Geosc 10 All

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An unconformity is:

A time gap in a sequence of sedimentary rocks caused by a period of erosion or nondeposition.

Tsunamis:

Are caused by earthquakes, undersea volcanic eruptions, or anything else that displaces a lot of water in a hurry.

In a glacier, the ice moves fastest:

At the upper surface, where ice meets air

Religion and science always disagree.

False

The glacier shown above:

Has retreated, because a decrease in snowfall to the accumulation zone (A) or an increase in melting of the ablation zone (B) occurred.

Any region of limestone bedrock containing caves, sinkholes, springs, etc. is called:

Karst

What is the "Ring of Fire"?

The complex of volcanic arcs fed by subduction zones encircling the Pacific Ocean

Which is more likely to contain reliable information?

A refereed article in a learned journal.

Look at the picture above. What type of volcano is this?

A subduction-zone-type, steep andesitic stratovolcano

Evolutionary theory is used in the real world for:

Fighting diseases, and in other practical ways including guiding some techniques in computer science.

Most Americans support science because:

Science has helped make our lives easier, safer, etc.

Glaciers form where:

Snowfall exceeds melting for a long enough time.

What do the ptarmigan and the marmot below have in common?

They are both standing on glacially eroded surfaces.

Which of the following was probably important in contributing to extinction of most species at the same time the dinosaurs became extinct?

"Impact winter" caused when tiny pieces of dust or other materials, which were put in the air by the impact, blocked incoming sunshine for months or years, after larger pieces had fallen back to Earth.

Which is younger:

the tree

Science professors teach certain theories and not others (Newton's physics, and not Aristotle's, or Darwin's evolution and not Lamarck's). If you were to ask the professors why, a majority would tell you (more or less; not using exactly these words but with this meaning):

"Nature has repeatedly been asked (through experiment) which is better, and we are teaching the ones that made successful predictions, and not teaching the ones that failed."

You start with 800 parent atoms of a particular radioactive type, which decays to give stable offspring. You wait just long enough for two half lives to pass. You should expect to have how many parent atoms remaining (on average):

200

If Central Pennsylvania had a really dry year, and received only one-third of our usual rainfall, we would be just dry enough to be called desert if such dry years stayed for a long time. How much rainfall per year would we be receiving per year then? (In an average year, Pennsylvania gets about the same amount of precipitation as the average for the world)

1 foot

Pictures 1 and 2 [See image: UNIT 6.12] show two very different looking rivers. What can you say about them?

1 is a meandering stream with clay-rich banks, and 2 is a braided stream with sandy or gravelly banks.

You start with 200 parent atoms of a particular radioactive type, which decays in a single step to give a stable offspring, and you start with none of those stable offspring. You wait just long enough for two half lives to pass. You should expect to have how many offspring atoms (on average)(remember that the number of parents and the number of offspring add up to 200, so if you have 10 parents, you have 190 offspring because 10 and 190 add up to 200, and if you have 20 parents you have 180 offspring, and so on):

150

Both of the above pictures are along the Colorado River. The clear water of picture 1 and the muddy water of picture 2 appear quite different. What's going on?

2 is upstream of the Glen Canyon Dam, and 1 is downstream of the dam.

If all the water that falls on central Pennsylvania's Happy Valley in a year as snow or rain stayed here as water without being used or evaporated, if spread uniformly over the land, it would make a layer about how thick? (Pennsylvania gets about the same amount of precipitation as the average for the world.)

3 feet.

You start with 400 parent atoms of a particular radioactive type, which decays in a single step to give a stable offspring, and you start with none of those stable offspring. You wait just long enough for two half lives to pass. You should expect to have how many offspring atoms (on average)(remember that the number of parents and the number of offspring add up to 400, so if you have 10 parents, you have 390 offspring because 10 and 390 add up to 400, and if you have 20 parents you have 380 offspring, and so on):

300

You start with 400 parent atoms of a particular radioactive type, which decays to give stable offspring. You wait just long enough for three half lives to pass. You should expect to have how many parent atoms remaining (on average):

The great diversification of shelly fossils that marks the beginning of the Paleozoic Era occurred about:

570,000,000 years ago

Rising air expands and cools; sinking air is compressed and warms. Typically, the size of the temperature change is:

5oF/1000 ft change in elevation if condensation or evaporation are not occurring; 3oF/1000 ft change in elevation if condensation or evaporation are occurring.

The extinction of many types of dinosaurs occurred about:

65,000,000 years ago.

Continents:

=re the "unsinkable" part of the solid Earth; although a little of a continent might go down, most continental material stays near the surface.

Dr. Alley is pointing to a brownish zone exposed in the low bluff along Coast Guard Beach, Cape Cod National Seashore. The brown zone is rounded on the bottom, flat on the top, rests on sand and gravel, and has sand dunes on top. In the lower picture, Dr. Alley is showing that the brown zone contains twigs and other organic material.What is the brown zone doing here?

An ice block from the glacier was buried in sand and gravel, then melted to make a lake that filled with organic material.

In the first picture, Dr. Alley is pointing to a brownish zone exposed in the low bluff along Coast Guard Beach, Cape Cod National Seashore. The brown zone is rounded on the bottom, flat on the top, rests on sand and gravel, and has sand dunes on top. In the lower picture, Dr. Alley is showing that the brown zone contains twigs and other organic material.What is the brown zone doing here?

A block of ice from the glacier fell into an outwash plain deposited by the glacier's meltwater streams, and the ice later melted to leave a lake, the lake filled with peat and other organic materials, and was later buried by sand dunes, with erosion of coastal bluffs now exposing the deposit.

You put some atoms together, and they share or trade some electrons. What just happened was:

A chemical reaction.

Near Aaronsburg, PA, a company wanted to start a limestone quarry, and planned to pump lots of water out of the ground to make things fairly dry near the quarry so it wouldn't fill with water. Concern was raised—would this affect the nearby trout streams? So, a little harmless dye was placed in a sinkhole next to the proposed quarry, and a fire-engine pumper added a lot of water to the sinkhole. How long did it take, or will take, for the dye to reach the trout stream?

A few hours to days.

Acadia National Park has a long, rich and varied geologic history. The large island marked "I" in the middle of the above picture is composed of resistant granite from the long-ago closure of the proto-Atlantic. However, the shape of the island was formed by much more geologically recent processes (within the last 100,000 years or so).What is primarily responsible for the beautiful shape of the island?

A glacier flowed over the island, moving from left to right, smoothing the rocks encountered first and plucking rocks free from the other side.

The above picture shows:

A glacier, which is generally flowing toward you, carrying rocks picked up from the ridges; the yellow arrow points up one of the stripes of rock, and you can follow the stripe to the ridge where the rocks started.

This rock in the picture above was modified by:

A glacier, which scratched and polished the rock at A and plucked blocks loose at B, as the ice moved from A to B.

Which is accurate about the Grand Canyon, in Arizona:

A great thickness of sedimentary rocks exists in Death-Valley-type faulted basins, which can be seen deep in the canyon in many places.

A widely accepted scientific idea usually is based on:

An interlocking web of important experimental results or observations that support the correctness of the idea.

Two yellow lines have been drawn on the picture by the instructional team. These lines follow an interesting surface, which separate flat-lying sedimentary rocks, on top, from slanting sedimentary rocks beneath. This surface is:

A great unconformity, with sedimentary rocks above resting on older sedimentary rocks below.

What is indicated by the yellow lines in the image above, which separate flat-lying sedimentary rocks, on top, from slanting sedimentary rocks beneath?

A great unconformity, with sedimentary rocks above resting on older sedimentary rocks below.

Look at the picture above. What happened here?

A great volcanic explosion occurred, spreading material across the landscape and leaving a hole.

In the photo above, [See image: UNIT 7.13] the letters A and B are in bowl-shaped features in east Greenland. The yellow arrow in the far upper right points to a peak between bowl B and two other bowls, one on the far side of the peak, and one on the right of the peak. What name should be applied to the peak between the three bowls?

A horn, left between the bowls that gnawed into the mountain.

What can you learn about past environments from sediments and sedimentary rocks?

A huge amount, including whether the environment was land or water, whether it was warm enough for crocodiles or cold enough for ice, and much more.

The picture above shows an odd cave on Hawaii. How did it form?

A lava flow solidified on the outside, and then the center drained out, leaving the space.

Geological evidence based on several radiometric techniques has provided a scientifically well-accepted age for the Earth. Represent that age of the Earth as the 100-yard length of a football field, and any time interval can be represented as some distance on the field. (So something that lasted one-tenth of the age of the Earth would be ten yards, and something that lasted one-half of the age of the Earth would be fifty yards.) On this scale, the time from when dinosaur extinction made space for large mammals, until today, would be represented by how far on the football field?

A little over 1 yard

The Marcellus shale is:

A major new source of gas that has become available because people developed the technological tools to recover the gas.

The ridge left behind by a glacier that outlines where the glacier had been is called

A moraine, composed of till (which is unsorted) and outwash (which is sorted).

The picture above [See image: UNIT 7.12] shows a glacier in eastern Greenland, in the world's largest national park, flowing from mountains at the top of Jameson Land (at the top of the picture) toward the lowlands of Kong Oskar Fjord (just out of the picture at the bottom).The yellow arrow from the letter C is pointing at a geological feature. What is that feature?

A moraine, left behind when the glacier retreated because of an increase in melting of the ablation zone or a decrease in snowfall in the accumulation zone.

When scientists agree that a particular scientific theory is a good one, and the scientists use that theory to help make new things, cure diseases, etc., that "agreement" came about because:

A number of different experiments by different people all had outcomes that were well-predicted by the theory.

Scientists often speak of consensus: the scientific community agrees that a particular theory is better than the competitors. What is such scientific consensus based on?

A number of different experiments by different people that all had outcomes that were predicted accurately by the favored theory and not by the competitors.

If North America and Asia continue drifting towards each other across the Pacific at their modern rates, they may someday experience the same type of tectonic activity that formed the Appalachians. What is this?

A push-together obduction boundary.

The picture above shows:

A right-side-up dinosaur track.

You see a hot-spot volcano on the surface of the Earth. What is under this volcano?

A rising tower of hot rock from deeper in the mantle, and perhaps all the way from the bottom of the mantle.

When we speak of the Mississippi Delta, most people mean some interesting region in Louisiana with good music and seafood. Geologically, however, the Mississippi Delta is:

A river-built deposit that is several miles thick at its thickest point, and extends from near St. Louis, Missouri to the Gulf of Mexico.

The pink arrows point to a barrier beach, formed when waves fromthe ocean (on the left) washed away mud and piled up sand, after themud and sand were delivered by the stream flowing in from the upperright. The yellow arrows point to interesting features.How did they form?

A storm broke through the barrier beach and pushed sand farther inland.

The picture above shows an outcrop along Interstate 70 in Utah. The green arrow points to a person, for scale. Between the pink arrows, there is an interesting surface. What is it?

An unconformity, where erosion occurred before the rocks above were deposited.

The peer review process, in which scientists submit write-ups of their ideas and experiments to a set of colleagues who judge how good the ideas are before the ideas can be published, is:

A useful and important, even if imperfect, mechanism of quality-control for the scientific literature.

Look at the picture above which shows a region just less than a foot across, of a stream deposit from the base of the same pile of rocks that show up in Bryce Canyon. This picture was taken in the face of a cliff in Red Canyon, just west of Bryce Canyon National Park. A indicates a piece of limestone that has been rounded off in a stream; B indicates a mass of sand glued together by hard-water deposits, and C indicates another such mass of sand glued together by hard-water deposits . In order of time of formation, they are:

A was formed first, then B was glued together by hard-water deposits, then C was glued together by hard-water deposits.

Which of the following is commonly expected near a "textbook" subduction zone (that is, near a subduction zone that is so perfect and free of confusing complications that you would use it in a textbook to teach students)?

Andesitic stratovolcanoes, such as Mt. St. Helens, fed by melt from the slab being subducted.

When considering the land surface:

Deposition of sediments occurs in only a few places, with erosion or nondeposition occurring in most places to produce unconformities, and one must piece together geologic history from rocks in many places.

Oxygen (O2) and nitrogen (N2) do not have much greenhouse effect, but several trace gases including carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and various chlorofluorocarbons are important greenhouse gases. The primary mechanism by which these greenhouse gases warm the Earth is:

Absorbing some of the infrared radiation emitted from the Earth.

Regions with mountain glaciers that experience much surface melting in the summer typically are eroded:

At a faster rate than regions with streams but no glaciers.

Which of the following was probably important in contributing to extinction of most species at the same time the dinosaurs became extinct?

Acid rain, from sulfuric acid from the meteorite hitting sulfur-bearing rocks, and from nitric acid from the heat of the meteorite burning the air.

Air moves in from the Pacific, over the Sierra Nevada (a mountain range), and down towards Death Valley. What happens?

Air moving down the east slope toward Death Valley is compressed, and warms by about 5 degrees F per thousand feet downward.

We now know a lot about the big processes that shape the Earth's geology. Which of the following is NOT correct about that knowledge?

Almost all of the motion of lithospheric plates is vertical, with almost no horizontal motion.

Humans (and our crops and pets and farm animals) now use:

Almost half of the things the planet makes available and that we like to use.

What is accurate about the planet's climate system?

Almost the same amount of energy is received from the sun as is sent back to space, but shortwave radiation is received and longwave radiation is sent back to space.

Suppose that tomorrow someone bulldozed all the rocks in the Appalachians, right down to sea level, and shipped all of those bulldozed rocks to Uzbekistan to build ski slopes. A few thousand years from now, we probably would find that the surface of the Earth exposed by the bulldozers was:

Almost, but not quite, as high as the Appalachians are today, because the roots of the mountains bobbed up.

Death Valley National Park preserves the lowest-elevation, hottest piece of the U.S. The park is fascinating for many reasons. What is accurate about volcanoes and Death Valley National Park?

Although no volcanoes are actively erupting at the moment this is being typed, eruptions have occurred in the geologically recent past (the most recent centuries or millennia), demonstrating the presence of hot rock at shallow depth beneath the valley.

In the photo above, the letters A and B are in bowl-shaped features in east Greenland. If you were to walk along the ridge just below the yellow line, you would be balanced on a knife-edged ridge between the two bowls. That ridge is called:

An arête, left between the bowls formed by two glaciers that gnawed into the mountain from either side.

Chemists recognize many different elements, such as gold, or oxygen, or carbon. Suppose you got some carbon, and started splitting it into smaller pieces. The smallest piece that would still be called "carbon" would be:

An atom

You get some stuff, and start taking it apart. But, you are restricted to the use of "ordinary" means (fire, sunlight, your digestive system) and you cannot use atom smashers or atom bombs. What is the smallest piece that you are likely to be able to produce:

An atom

The picture above shows Telescope Peak, towering above Death Valley.The straight edge of the alluvial fan in the foreground is:

An earthquake fault, where the valley has dropped relative to the mountains.

In 2005, Hurricane Katrina brought a storm surge that overtopped the levees and flooded New Orleans, causing over 1400 deaths and perhaps $100 billion in damages. This flooding of New Orleans from a big storm was:

An event that scientists had warned about for decades, based on the known size of hurricanes, and the sinking of the city and the Delta.

The age of the Earth can be estimated in many ways. Which statement below is most accurate (remember that uniformitarian calculations involve looking at the thickness and type of sedimentary rocks, and similar things, but do NOT include radiometric dating or counting of annual layers)?

Annual-layer counting shows that the Earth is more than about 100 thousand years old, uniformitarian calculations show that the Earth is more than about 100 million years old, and radiometric techniques tell us how old the Earth is.

Heating of some materials produces coal. The most-heated is the most valuable. In order, from the MOST-VALUABLE/MOST-HEATED (FIRST) to the least-valuable/least-heated (LAST), the coals (and material that gives coal) are:

Anthracite, bituminous, lignite, peat.

If you get some of the right sort of organic material, and heat it in the right sort of way, perhaps with a little squeezing, you will end up with coal. The most-heated is the most valuable. In order, from the MOST-VALUABLE/MOST-HEATED (FIRST) to the least-valuable/least-heated (LAST), the coals (and material that gives coal) are:

Anthracite, bituminous, lignite, peat.

Most earthquakes:

Are caused when rocks on opposite sides of a break, or fault, in the Earth's crust move in different directions, and the fault is poorly lubricated, so the rocks along the fault get stuck for a while and bend their neighbors before breaking free and moving.

When geologists consider sedimentary rocks, those rocks:

Are classified first based on origin (clastic or chemical precipitate).

Transitional forms between distinct types (species) of different ages in the fossil record:

Are common for commonly fossilized types, but rare for rarely fossilized types.

Tsunamis:

Are like tornadoes; they can be predicted with some accuracy seconds to hours before they strike in most cases, allowing quick warnings to save many lives.

The volcanoes on the island of Hawaii (and the Loihi seamount, a submerged volcano to the southwest of Hawaii):

Are not located at a subduction zone or other plate boundary, but instead poke through a plate drifting over the Hawaiian hotspot.

Air moves in from the Pacific, over the Sierra Nevada (a mountain range), and down towards Death Valley. What happens?

As the air rises up the Sierra, the air expands, making rain and snow, and cooling by 3 degrees F per thousand feet upward.

What geological processes have caused the Grand Canyon to be wider at the top than at the bottom?

As the river cuts down, the steep walls of the canyon experience mass movement (rocks fall, slump, creep or otherwise move off the walls and down to the river), so the top of the canyon is widening as the river deepens the bottom.

The recent changes in the amount of ice on Earth over time occurred:

At regular and repeating times, controlled by redistribution of sunlight on the surface of the Earth in response to features of Earth's orbit, even though total sunshine received by the planet didn't change much.

Which is the correct age progression, from younger (first) to older (last)?

B F E D C

The above diagram is from one of the Geomations in the unit. It shows three possible fault styles. A and B are cross-sections, with a collapsed building on top to show you which way is up—the yellow band is a distinctive layer of rock that was broken by the earthquake that also knocked down the building. C is viewed from a helicopter, looking down on a road with a dashed yellow line down the middle; the road was broken by an earthquake along the green fault, and the earthquake knocked down a building to make the funky-looking brown pile in the upper right.What is accurate about the different earthquake styles?

B is pull-apart, C is slide-past, and A is push-together.

Two neutral atoms have the same number of protons in the nucleus, but different numbers of neutrons. These are:

Different isotopes of the same element.

Which of the following is part of the modern theory of evolution?

Diversity exists within a species, and "experiments" that tend to promote diversity sometimes occur during reproduction.

Which of the following is not expected very often near a "textbook" subduction zone(that is, near a subduction zone that is so perfect and free of confusing complications that you would use it in a textbook to teach students)?

Basaltic hot-spot volcanoes such as Hawaii.

The sea floor that forms at spreading ridges and then moves away will:

Be subducted, with most of the material going back into the mantle, balancing the material coming out to make the new sea floor.

The recent changes in the amount of ice on Earth over time occurred:

Because changes in the Earth's orbit have caused changes in the amount of sunshine received during certain seasons at different places on Earth.

Convection occurs:

Because hotter things are less dense and tend to rise.

The above picture shows ocean in the upper right, a beach, andland (lower left). The red dashes trace the crest of a wave. Wavesmove perpendicular to their crests.What principle is illustrated by the picture?

Because waves go slower in shallower water, waves turn and move almost directly towards the beach, but the little bit of along-beach motion remaining drives longshore transport.

You are flying along the coast, and you observe a sort of dam or wall, called a groin, sticking out from the coast. Sediment has piled up on one side of the groin, with erosion on the other side. You can reasonably infer that:

Before the groin was built, sediment transport in the longshore drift was dominantly from the side with the sediment deposit to the side with the erosion, and the groin has interrupted some of this transport.

Extinction removes biodiversity, and evolution generates biodiversity. The balance between extinction and evolution controls the Earth's biodiversity. Based on the scientific evidence summarized in the text and in class:

Biodiversity fluctuates about a balance, with short-lived mass extinctions lowering biodiversity and subsequently evolution exceeding extinction over tens of millions of years to increase biodiversity until a new balance is reached.

If you were looking for different types of coal, you likely would find:

Bituminous in the sedimentary rocks of western Pennsylvania, and anthracite in the metamorphic rocks of eastern Pennsylvania.

Some natural resources are renewable—nature produces them fast enough that humans can obtain valuable and useful supplies of a resource without depleting it. Other natural resources are nonrenewable—if we use the resource at a rate fast enough to matter to our economy, the resource will run out because use is much faster than natural production. What do we know about oil and coal?

Both oil and coal are nonrenewable resources, and at current usage rates and prices similar to today, oil will run out in about a century and coal will run out in a few centuries.

What do we know about the effects of humans on extinction of plant and animal species on Earth?

Both prehistoric and modern humans have been responsible for extinctions.

You are the chief biodiversity officer for the National Park Service in the eastern US, responsible for maintaining as much diversity as possible, and your boss has told you to focus on maintaining biodiversity of things big enough to see with the naked eye (so you don't need to worry about microorganisms). You have two parks, and enough money to buy 10,000 acres of land. You may add the 10,000 acres to one of the parks, add 5,000 acres to each park while leaving them as isolated parks, or buy a 10,000-acre corridor connecting the two parks. All of the land for sale is now wilderness, but the land you do not buy is going to be paved for a super-mega-mall. You would be wise to:

Buy the corridor connecting the two parks; this keeps one big "island" rather than two smaller ones, and so keeps more species.

The diagram above shows a geologic cross-section of some rocks, such as you might see in a cliff. The tree is growing on top of the modern surface. Rock layers A, B, C, D, E, and F are sedimentary; E contains mud cracks and fossil footprints as shown. G is igneous rock that hardened from hot, melted rock. H, I and J are faults, and K and L are unconformities. Sedimentary rocks are right-side-up unless there is some indication given to show something else. Referring to the rocks you see here ......Which is the oldest sedimentary rock layer?

Clay consists of new minerals commonly formed by:

Chemical weathering of feldspar (feldspar contains silica, aluminum, potassium and other things)

If you went swimming in the single channel of this river, and grabbed a sample of the river bank, what would you likely come up with?

Clay, that sticks together and can hold up steep slopes.

Chemical weathering of a continental rock such as granite in a climate such as that of Pennsylvania or other places where a good bit of rain falls, produces:

Clays and rust, that do not wash away easily, and soluble ions, that do wash away easily

Regarding global warming, most scientists (including those who have advised the United Nations through the Intergovernmental Panel on Climate Change) agree that if we continue to burn fossil fuels at an accelerating rate:

Climate changes will primarily hurt poor people in warm places, but the climate changes are primarily being caused by wealthier people in colder places.

Which is the correct age progression, from older (first) to younger (last)?

C,D,E,F,B

Which formula describes the chemical changes that occur and release energy when you start with plant material and then burn it in a fire or "burn" it in a stomach?

CH2O + O2 → CO2 + H2O

Which formula most closely describes the process by which plants make more of themselves:

CO2 + H2O + energy → CH2O + O2

The idea that human activities will cause global warming is well over a century old now. The United Nations has been sponsoring studies of this idea for almost two decades. The assembled scientists have concluded, with high confidence, that:

CO2 levels in the atmosphere have been rising, warming the planet a degree or so, and burning all the remaining fossil fuels likely will raise the Earth's temperature many degrees or more.

The great disaster at Lake Nyos in Cameroon, Africa, in which hundreds of people died, occurred when this material was released from the volcano:

Carbon dioxide (CO2) that suffocated the people.

You watched online as Dr. Alley carved a sand canyon with his finger. Based on what you saw, and on what you know about slopes, stability, mass movement, etc., if a landslide happened someplace last week, you would tell the neighbors:

Care is required; landslides are removing instabilities and moving things towards stability, but a second landslide, or a flood, or other problems are real possibilities.

One way that sediment is changed to sedimentary rock is by:

Cementation, a process that occurs in nature, and that is similar to processes that can occur in plumbing and other things humans make. Cementation, a process that occurs in nature, and that is similar to processes that can occur in plumbing and other things humans make.

The geologic time scale is, starting with the youngest and ending with the oldest:

Cenozoic, Mesozoic, Paleozoic, Precambrian.

During the most recent ice age:

Central Pennsylvania was just beyond the edge of the Canadian ice.

Volcanic eruptions cause many hazards to humans, and many geologists are employed to study these hazards and warn people. For a single, large, explosive volcanic eruption, which of the following is not a worry that these volcanic-hazards geologists would warn people about?

Climatic warming, with the volcano causing a sudden heat wave that would harm people around the world living in big cities.

Which of the following is NOT a job that geology graduates commonly get hired for:

Cloning new biological organisms for use in international terrorism.

Among fossil fuels:

Coal is made by heating of woody plant material, and oil is made by heating of algae.

What cause probably was not important in contributing to extinction of most species on Earth, including the dinosaurs, in a very short interval of time at the end of the Mesozoic Era?

Cold from the change in Earth's orbit caused when the meteorite shoved the planet farther from the sun.

Air can be heated in many different ways. At night, if air moves up one side of a mountain range such as the Sierra Nevada, raining or snowing on the way, and then down the other side, the air is hotter after moving over than it was before. What is the main reason, as discussed in the class materials?

Condensation of water vapor to form clouds and rain releases heat that was stored when the water evaporated.

Heat is moved around by convection, conduction and radiation (and by lemmings carrying space heaters, if lemmings ever carry space heaters). Which statement is more nearly correct?

Convection moves heat efficiently through the soft, hot rocks of the Earth's mantle, but is not efficient at moving heat through the space between the Sun and the Earth.

You find an atom, and you want to learn what element it is (its fundamental type). If you are efficient, you first should:

Count the number of protons contained in the nucleus of the atom.

Considering long-term averages, and assuming that we don't deploy space-based defenses against incoming meteorites, a reasonable estimate of the chance of an average U.S. citizen being killed by the effects of a meteorite or comet impact is that this risk is about the same as the chance of being killed by:

Crash of a commercial airplane.

When humans build or raise levees along big rivers such as the lower part of the Mississippi, we are likely to cause:

Fields and roads on the flood plain to drop below the surface of the river, because compaction of flood-plain mud will no longer be balanced by sediment accumulation during floods.

Which of the following is part of the modern theory of evolution?

If a reproductive "experiment" is successful, it will be passed to more and more children in successive generations until all members of a population have it.

Which of the following is not a part of the modern theory of evolution?

If the body of an adult living thing is changed by its environment, those changes usually are passed on biologically to children.

The processes that made Death Valley continue to operate today. For this question, ignore the sand and gravel moved by water and wind, and think about the big motions of the rocks beneath. Choose the best answer: what are they doing to the valley?

Death Valley is getting wider and deeper.

Subduction zones produce an amazing variety of geological features. These include:

Deep trenches in the sea floor, formed by the bending of the downgoing plate, and sometimes filled with sea water but sometimes filled with sediment eroded from nearby land.

Glaciers move by:

Deformation within the ice, and sometimes sliding over materials beneath or deformation within materials beneath.

The North Pole sticks up out of Dr. Alley's bald spot, and the equator crosses his nose and cheeks.

Dr. Alley may get a sunburned nose, and the equator is hotter than the pole on the real Earth, primarily because the sun hits the equator directly but the sun hits the pole a glancing blow.

The volcanoes of the island of Hawaii eventually will:

Drift off the hot spot and cease to erupt, while a new volcano grows to their southeast.

To get gas from the Marcellus shale, drillers:

Drill into and then along the shale, and then pump in high-pressure fluids to fracture the rock and release the gas.

Some eruptions come out of volcanoes really rapidly and shoot really high because:

Dropping pressure as the melt rises allows volatiles including water vapor and carbon dioxide to make bubbles that lower the density and make the melt rise even faster.

What is one of the main, common-sense ideas that geologists use to learn what happened first and what happened later in geologic history?

If you see a push-together fault cutting a clastic sedimentary rock, you know that the sediment was deposited, and then broken by squeezing, because something must exist before you can break it.

Look at the picture above, from the coast of Olympic National Park. What happened here?

Earthquakes knocked loose undersea muds that raced down the slopes of the west coast into the subduction zone, making rocks that were then scraped off the downgoing slab to make part of Olympic National Park.

Heat transfer by convection is:

Efficient through hot, soft rocks such as the deep mantle, but inefficient through outer space.

You are asked to assign as accurate a numerical age as possible (how many years old) to a sedimentary deposit. You would be wise to use:

Either counting of annual layers or radiometric techniques if the deposit is young (less than about 100,000 years), and radiometric techniques if the deposit is old (more than about 100,000 years).

A common way in which Philadelphia-size or bigger bodies of rock that were heated and squeezed deep in a mountain range then end up at the surface of the Earth is:

Erosion removes the overlying mountains, and the deeper rocks float to the surface.

You get in your Magic School Bus, drive down the throat of a volcano, and find that you are driving through melted rock that flows with much greater difficulty than does most melted rock, because the melted rock you are driving through is lumpier than typical for melted rock. It is likely that the melted rock you are driving through is:

Especially low in water and carbon dioxide compared to most melted rocks.

In the photo above, Dave and Kym are discussing a model of the Waterpocket Fold in Capitol Reef National Park. The Waterpocket probably formed in the same way as the Front Range of the Rockies.This involved:

Especially warm sea floor in the subduction zone off the west coast rubbed along under western North America and squeezed or wrinkled the rocks, folding them (probably with a push-together fault somewhat deeper under the fold).

Evolution produces new types, and extinction gets rid of them. The scientific evidence summarized in the text and in class shows that:

Evolution and extinction are usually more-or-less in balance, but occasional mass extinctions reduce biodiversity, and subsequent evolution faster than extinction increases biodiversity until a new balance is reached.

Which of the following is not a part of the modern theory of evolution?

Evolution proceeds in the direction desired by members of a generation.

Scientists promote the teaching of evolutionary theory, in part to raise new scientists to help use evolutionary theory. How are scientists using evolutionary theory in efforts that can help people?

Evolutionary theory is being used to understand, and help fight, the emergence of antibiotic-resistant diseases and other new diseases, and even to guide thinking in computer science.

Which of the following is not a scientifically accepted statement about the occurrence of transitional forms in the fossil record?

Evolutionary theory shows that many lineages should have developed by "Ford Mustang" evolution without transitions.

What probably happened to create the two rocks with the orange surfaces, seen in the center of the above picture from Greenland?

Expansion from water freezing in the crack wedged the rock apart.

What is accurate about the history of extinction of species:

Extinction happens at a slow, "background" rate, punctuated by rare "mass extinctions" during which many types are eliminated rapidly.

What is accurate about humans and extinctions?

Extinction has always happened naturally, but humans have accelerated the rate of extinction; both early humans and modern humans have contributed to extinction.

If you are drilling a well to reach water, you usually will have to drill:

Farther into the ground to make a deeper well on a ridge than in a valley.

If you hike down into Bryce Canyon, and you look up the correct stream bed, you'll see this.The trees lying across the stream bed in the photo above (between the pink arrows) are a small dam. What has happened here?

Fast-flowing floods have lost their debris when slowed by the dam, filling the space above the dam with rocks. This basic pattern—dams collect debris and release clean(er) water that can erode more, is seen over and over in geology. And, marmots don't dig that much at Bryce!

Hot spots usually:

Feed basaltic volcanoes (composition similar to sea floor), unless the hot spot is altered in composition coming through a continent, in which case the volcano may be more andesitic.

If humans change the composition of the atmosphere in a way that would warm the world by one degree if everything else in the Earth system remained unchanged, most studies indicate that over the next years to decades:

Feedback processes will enhance this warming a little, causing the total warming to be a few degrees.

Your job depends on you finding the best available information on a particular technical topic. Where should you concentrate your search if you want to do it right and keep your job?

Find and study refereed scientific articles in learned journals.

The jobs of geologists include:

Finding valuable things in the Earth, warning about hazards, learning how the Earth works, and educating and entertaining people.

In the picture above, the ice that modified the rock moved:

From left to right, striating the surfaces the ice reached first and plucking blocks loose from the far sides of bumps.

A glacier almost always flows:

From where the glacier's upper surface is high to where the glacier's upper surface is low.

As water from rain soaks through the soil, the water typically:

Gains carbon dioxide (CO ) from the air and then gains more carbon dioxide in the soil, becoming more acidic.

As rain falls through air, the water typically:

Gains carbon dioxide (CO2) from the air, becoming a weak acid

Pure water can cause changes in some rocks, but real natural rainwater is more effective than pure water at changing rocks. This is because rainwater typically:

Gains carbon dioxide (CO2) from the air, becoming a weak acid

The New Madrid Fault Zone in Missouri has had some surprisingly big earthquakes. A magneto-hydro-astronomer at a small university near the fault zone reports that the gravitational effects of the coming alignment of several planets, together with the weakening of the magnetic field, will cause a giant earthquake on the fault zone on Wednesday morning between 1 and 4 am. Based on materials covered so far in this class, you would be wise to:

Get back to whatever you were doing and ignore the forecast; although there might be a very small effect of planetary gravity or magnetic fields on earthquakes, no one has ever demonstrated the ability to make such detailed forecasts accurately, and many such forecasts have proven to be wrong.

In affecting the landscape:

Glaciers that are frozen to their beds don't do much, but glaciers that are thawed at their beds and have a lot of meltwater change things rapidly.

Most U.S. beaches are shrinking or encroaching on the land rather than growing or moving seaward, so the land of the U.S. is getting smaller, not bigger. Causes include:

Global sea level is rising, covering more land.

Sedimentary rocks composed of clasts or chunks are usually subclassified by geologists based on:

Grain size—rocks made of big pieces are given different names than are rocks made of little pieces.

Which is the youngest fault:

The Mississippi River:

Has built a delta, which is several miles thick at its thickest point, from near St. Louis, MO to the Gulf of Mexico over millions of years.

Volcanoes in Death Valley:

Have erupted recently (within the last centuries or millennia) showing that hot rock occurs at shallow depth beneath the valley

Continents:

Have grown in area over time primarily by addition of island arcs, seamounts and sediments scraped off subducting slabs.

Which statement is true about the physical conditions required for convection to occur?

Heating from below, which reduces density and causes a tendency for the heated material to rise.

The law that established the National Parks gave them a hard job, because it required that they:

Help people enjoy the parks today, but also save the parks for the future.

The above picture is from the Escalante-Grand Staircase National Monument. The pink arrows point along some interesting features.What are they?

Joints, formed when the sedimentary rocks were broken by physical-weathering or other processes.

Which of the following is not part of the evidence that the odd layer marking the extinction of the dinosaurs was caused by a large meteorite impact?

High concentrations of iron found in the layer

Which of the following is not part of the evidence that the odd layer marking the extinction of the dinosaurs was caused by a large meteorite impact?

High concentrations of silica found in the layer.

What geologic setting is primarily responsible for producing Hawaii's volcanoes?

Hot Spot

Yellowstone is in some ways similar to Hawaii. This is because both are:

Hot spot volcanic regions

Lithospheric plates move on the surface of the planet. Plates meet at long plate boundaries. The types of interactions at these boundaries are very important. Which is NOT an interaction type commonly observed along the length of one of these boundaries?

Hot spot.

The interactions at the edges of plates are very important. Which is NOT an interaction that is commonly observed all along the length of one of the edges where two plates meet?

Hot spot.

The consensus of the world's climate scientists, as generated by the UN-sponsored Intergovernmental Panel on Climate Change (IPCC), is that:

Human activities have raised CO2 levels in the atmosphere, warming the planet, and the changes so far have been small compared to the changes that are likely over the next centuries unless we humans alter our behavior.

Examine the two pictures above, labeled I and II. They are from the same sediment core collected in sea-floor muds from beneath the Atlantic Ocean off the coast of South Carolina. (The pictures are scanning electron micrographs by Brian Huber of the Smithsonian Institution, and the scale is the same on both, as shown at the bottom of each.) One picture shows a sample from just below the unique layer marking the extinction that killed the dinosaurs, and the other picture shows a sample from just above that unique layer. Which is which?

I is from below the unique layer, and II is from above the unique layer.

The pictures labeled I and II show fossils from a sediment core collected from the floor of the Atlantic ocean, east of South Carolina. The sediment has not been disturbed by landslides or mountain building or other processes. The pictures were taken by Brian Huber, of the Smithsonian Institution, using a scanning electron microscope. The two samples in the sediment core were separated by the unique layer marking the extinction that killed the dinosaurs.Which is correct?

I is older than the unique layer, and thus sat below the unique layer in the sediment on the sea floor.

Which correctly gives the order of the faults, from oldest (first) to youngest (last):

I,J,H

During the most recent ice age:

Ice from Canada advanced across the Great Lakes and into the northern states of the US, but not farther.

Icebergs float in water and continents float above the mantle because:

Icebergs/continents are less-dense than the stuff they float in.

You hear an astronomer on the evening news, pointing out a coming alignment of planets and predicting that the extra gravitational attraction is sure to trigger a huge earthquake in California during the few hours of alignment. Based on what has been covered in this class, a reasonable approach is to:

Ignore it; although gravitational forces such as tides and planetary pulls might possibly exert a very small effect on earthquakes, no one has successfully predicted the where-and-when of earthquakes.

A University of Michigan student visiting Penn State's University Park campus drinks too much Diet Pepsi, wanders out in a pouring rainstorm, and takes a leak in a sinkhole behind the nearby Nittany Mall. The trout in the stream to which the sinkhole drains will notice the dastardly deed:

In a few hours to days.

What is an important idea that geologists use to put sedimentary rocks in order from older to younger?

In a normal pile of sedimentary layers, the layer on the bottom is the oldest, and the layer on the top is the youngest.

Given the materials presented in this class about the formation of caves, it is likely that most large caves are formed:

In limestone in moist climates.

Which is accurate about the history of the Grand Canyon:

In the deepest part of the canyon, the river cuts through rocks formed by metamorphism of older sedimentary rocks in the heart of a mountain range.

The best description of a scientist's job is that she or he:

Invents new ideas, and shows that some ideas are false.

The Mesozoic:

Is "middle life", the age of dinosaurs.

The Cenozoic:

Is "new life", the age of mammals.

The Paleozoic:

Is "old life", the age of shellfish.

Mt. St. Helens, in the state of Washington:

Is a medium-to-high-silica andesitic volcano, different from the lower-silica basaltic volcanoes of Hawaii.

If you watched a sand grain moved by waves on a beach on the U.S. east coast, you would usually see that most of its motion:

Is alternately toward and away from the shore, causing little net change.

Most commonly, a hot-spot volcano:

Is basaltic in composition.

Early geologists did not have radiometric dating techniques, or long layer-counted histories. Instead, they followed William Smith in putting things in order, and then used uniformitarian calculations based on modern rates of processes and observed results of processes in the geologic record. These early geologists, using these techniques, found that the Earth:

Is more than about one-hundred-million years old.

Using only uniformitarian calculations from the thickness of known sedimentary rocks, likely rates at which those rocks accumulated, and features in and under those sedimentary rocks, geologists working two to three hundred years ago estimated that the Earth:

Is more than about one-hundred-million years old.

The gas from the Marcellus shale:

Is produced by "fracking", which uses high-pressure water and chemicals to make new "fractures" in the shale that allow the gas to escape to wells.

The Precambrian:

Is the age of algae, and occurred just before the Paleozoic.

Calcium released by chemical weathering is transported by streams to the ocean, where much of it:

Is used by clams, corals, etc. to make their shells

Silica released by chemical weathering is transported by streams to the ocean, where much of it:

Is used by sea creatures to make their shells

One way to treat a dying beach is to dig up sand somewhere and dump it on the beach. What is this likely to accomplish?

It causes the beach to lose the new sand over the next year or years, as the extra sand is washed back to deep water by waves and currents.

What is accurate about peer review of scientific papers?

It provides quality control by eliminating many mistakes.

Geological evidence based on several radiometric techniques has provided a scientifically well-accepted age for the Earth. Represent that age of the Earth as the 100-yard length of a football field, and any time interval can be represented as some distance on the field. (So something that lasted one-tenth of the age of the Earth would be ten yards, and something that lasted one-half of the age of the Earth would be fifty yards.) On this scale, how far on the football field would represent the time between the first appearance of abundant shelly creatures and today?

Just over 10 yards.

Most U.S. beaches are shrinking or encroaching on the land rather than growing or moving seaward, so the land of the U.S. is getting smaller, not bigger. Which of the following is a likely cause for loss of at least some of our beaches:

Land is sinking in some places as it recovers from being bulged up beyond the edge of the ice-age ice sheets.

A grand piano in a house in one of the lowest-elevation regions of New Orleans protected by the human-made levees is:

Lower in elevation than a kayaker on the river when the river is carrying its average water flow.

It would be really nice to know whether an earthquake is coming, so we could prepare for it. At this time, we are able to:

Make reasonably accurate estimates of where earthquake damage is likely, and how bad earthquake damage is likely to be, but not exactly when an earthquake will occur.

The above picture shows a region a bit under a foot across, in a cliff in Red Canyon, just west of Bryce Canyon National Park. The rocks in the picture are the same as the rocks at the bottom of the beautiful Bryce Formation, the pastel rocks in Bryce Canyon. The red arrows surround a very interesting, reddish clast.What is the geological interpretation of this picture?

Many older rocks, some with interesting histories, were rounded in a river, then mixed with sand and glued together by hard-water deposits; the resulting rock layer was broken into pieces, which were rounded in a stream, mixed with other rocks and sand and glued together by hard-water deposits, and the resulting rock layer was raised out of the river, and eroded to yield the modern outcrop.

What is accurate about the scientific results learned by counting annual layers in ice cores?

Many tests show that some ice cores have reliably preserved annual layers, and the longest record extends back more than 100,000 years.

What is accurate about the scientific results learned by counting tree rings and other annual layers?

Records in tree rings, lakes and ice all reach beyond 12,000 years, and some of them reach beyond 40,000 years.

In the picture above, the dark stripes on the surface of the glacier are:

Medial moraines, rocks picked up from points where tributary glaciers flow together.

You are told that a region has no glaciers. What does the lack of glaciers tell you about the climate of that region?

Melting removes all of the snowfall.

What sort of rock is pictured above?

Metamorphic; The rock separated into layers as it was cooked and squeezed deep in a mountain range.

What sort of rock is the dark material very close to the pink granitethat Dr. Alley is pointing to in the picture above?

Metamorphic; The rock separated into layers as it was cooked and squeezed deep in a mountain range.

A larger national park and a smaller national park, otherwise identical, are completely surrounded by cornfields and Walmart parking lots, and have been surrounded for a century. You count the number of species of trees in each park. You probably will find:

More species in the larger park, because it can hold more individuals thus reducing the risk of extinction

Which is not part of our modern view of geology?

Most mountain building occurs in the centers of lithospheric plates.

A place such as central Pennsylvania, home of Penn State's University Park campus, is fairly typical of the world in terms of rainfall. What happens to the rain that falls on central Pennsylvania each year?

Most of it is evaporated.

During chemical weathering, sodium is released as dissolved ions and transported to the ocean, where:

Most of it stays in the water for a while, making the water salty.

Bigger earthquakes occur less frequently, but a bigger quake releases more energy and does more damage. An interesting question to ask about earthquakes (and about almost anything else!) is whether the increase in energy release and damage done is larger or smaller than the decrease in frequency as one looks at bigger earthquakes. Asked a different way, is most of the damage done by the many little earthquakes or by the few big earthquakes?

Most of the damage is done by the few, big earthquakes.

You wander around the world for a while and take pictures of many typical living things. If you then were to follow those living things to see what would happen to them after they die, and they behaved naturally, it is likely that:

Most of the living things would be "burned", combining with oxygen to fuel some other living thing, or would be burned in a real fire.

Weathering attacks a granite in Pennsylvania or Washington, DC, or a similarly rainy place. The feldspar grains in the granite primarily:

Mostly make clay that stays in the soil for a while, although some chemicals also dissolve and wash away to the ocean.

Major differences between Mt. St. Helens and Hawaiian volcanoes include:

Mt. St. Helens is a medium-to-high-silica stratovolcano, and Hawaii has low-silica shield volcanoes.

National Parks are:

Regions containing key biological, geological or cultural resources that have been set aside for the enjoyment of the present generation and future generations.

Much less than the thickness of a sheet of paper.

Dr. Alley has helped drill many holes in ice sheets. Special tools can be lowered down the holes on cables, and tracked to learn the shapes of the holes. Initially, the holes are straight up and down. Years later, the holes are bent, because the ice in the ice sheet is flowing. What does it mean to say that the ice is flowing?

Much like rocks in the mantle or iron heated by a blacksmith, the ice is almost hot enough to melt, and deforms as gravity pulls on it, without breaking into loose chunks.

The processes that made Death Valley have been operating for millions of years, and continue to operate today. For this question, ignore the sand and gravel moved by water and wind, and think about the big motions of the rocks beneath. If you had visited DeathValley 1 million years ago, you would have found the valley then to have been (choose the best answer):

Narrower and shallower than it is today.

Soil is produced by weathering of rocks, and moved to streams by mass-movement. Our understanding of nature and humans shows:

Naturally, soil thickness reaches an approximate balance, with soil production and loss about equal if averaged over an appropriate time, but human activities have upset this balance and caused soil to thin.

The final arbitrator between two alternate theories (for example Aristotle's and Newton's ideas) is:

Nature, and experiments conducted to test each idea.

In the photograph above, a portion of cliff about 30 feet high is shown.From what location in the Grand Canyon did Dr. Alley take this image?

Near the bottom, where the river has cut through rocks that were cooked, squeezed, and partially melted deep in an old mountain range.

If two drifting continents run into each other:

Neither will be subducted back into the deep mantle; instead, they will form an obduction zone.

Newton's ideas on physics "won", and Aristotle's ideas were kicked out of science and over into history. Why?

Newton's ideas did a better job of predicting how nature would behave.

You are a famous scientist, renowned for the well-accepted idea you developed over the last 15 years. A new idea suddenly appears from some upstart junior scientist. For the new idea to overthrow your well-accepted idea and gain widespread scientific acceptance, what must happen?

No matter how hard you and your friends wish that your children will be born with the ability to fly unassisted, the kids will have to use airlines like the rest of us. You can get a tattoo without worry that your children will be born with that same tattoo. A hopeful monster would have no one to mate with. And while sometimes bigger or more-complex kids do better, sometimes smaller or simpler ones do better. But, biological "experimentation" promoting diversity does occur, providing the variability on which natural selection occurs to cause evolution.

Extinction of existing species:

Occurred at a low level throughout geologic history, punctuated by mass extinctions when many types were killed over very short times.

At current rates of use, and at prices not greatly higher than those of today:

Oil will run out in a century or so, and coal will run out in a few centuries.

Rocks in continents are on average much older than sea-floor rocks. The likely explanation is:

Old sea floor is recycled back into the deep mantle at subduction zones at the same rate that new sea floor is produced, but continents are not taken into the mantle and so remain on the surface for a long time.

A scientist gains knowledge about how the world works and uses that information to successfully predict what will happen in an experiment. This proves that the scientist's knowledge is:

One or more of True, lucky, or close to being true (or cheating), but we can't tell which.

In the map above, blue shows the Mississippi River, and the Gulf of Mexico, around the Birdfoot Delta of the river. The USGS image uses different colors to indicate changes in the delta. Orange and red both indicate change in one direction, whereas yellow and green indicate change in the other direction. Based on the material presented in this class:

Orange and red indicate loss of wetlands over time, whereas yellow and green indicate gain of wetlands over time.

We saw when we studied weathering that physical weathering makes little pieces from big, and that chemical weathering dissolves some things and makes other chunks. The different chemicals went into different places, dissolved or in chunks. When geologists classify sedimentary rocks, the first divisions are based on:

Origin—rocks made from pre-existing pieces are separated from rocks made from precipitation of dissolved things.

Suppose that the sun suddenly became a little brighter, which would warm the world a little. Over the next few hundred years, what would you expect to happen?

Other things would change in the Earth system, and these feedbacks would amplify the warming from the sun a little and cause the Earth to end up somewhat warmer than before the sun changed.

Human population continues to grow. Looking at many of the things we use on Earth (farmland and land for wood and other things, fish in the sea, etc.):

Our use is large but not everything; we are approaching use of half of all that is available.

What is accurate about seismic waves moving through the Earth?

P-waves (also called push-waves or sound waves) move through liquids, but s-waves (also called shear waves) don't.

Geology departments are seeing a lot of recruiters recently, because geology is an in-demand major. Which of the following is NOT a job that geologists commonly end up doing?

Packaging substandard mortgages into "securities" and trying to sell them to unsuspecting people.

Heating of some materials produces coal. With increasing temperature and time, one observes:

Peat, lignite, bituminous, anthracite.

Large rivers have many interesting features, including:

The flood plain, the nearly flat region farther from the river than the natural levees and composed of mud deposited by the river's floods.

You start with some of the right kind of dead material, and heat this material in the right way, perhaps with a little squeezing. As the material changes, you end up with coal, and the name scientists give to the material changes. In order, from coolest (first) to warmest (last) the names given are:

Peat, lignite, bituminous, anthracite.

The pictures show famous volcanoes, that are discussed in the class materials. Which statement is most accurate about these?

Picture II shows a hot-spot-type shield volcano, and picture I shows a subduction-zone-type stratovolcano.

Many plants are hard to get along with. Imagine crashing pell-mell through a thicket of devil's club (pictured above),in coastal Alaska, to get away from a charging brown bear. The native people use devil's club for medicinal purposes.We now know that:

Plant protection by thorns is supplemented by chemicals that are poisonous to many things that would eat the plants; those chemicals are sometimes harmful to humans (poison ivy, for example) but sometimes beneficial to humans, and have given us many of our medicines.

The above photograph was taken in the Grand Canyon, and shows a cliff that is approximately 30 feet high. What are the rocks in the cliff?

Precambrian metamorphic rocks with some igneous rocks intruded; the folding was caused by mountain-building processes when the rocks were very hot deep in a mountain range.

The geologic time scale is, starting with the oldest and ending with the youngest:

Precambrian, Paleozoic, Mesozoic, Cenozoic.

Extinctions have occurred throughout Earth's history. What is accurate about the history of extinctions?

Prehistoric humans cause extinctions faster than is typical naturally, and modern humans are also causing extinctions.

Nuclei of atoms are made up of:

Protons, usually with neutrons added.

Ignoring good manners, you start rooting around in the nucleus of a poor, unsuspecting atom, to see what is in there. What are you most likely to find?

Protons, usually with some neutrons hanging around among the protons.

The picture above shows a fault in a place where mountains come down near the coast. What likely happened to form the ramp (also called a scarp) behind the person?

Pull-apart forces pulled the rocks apart, making the break, and allowing one side to drop relative to the other.

The picture above shows a view in the Earthquake Lake region just northwest of Yellowstone. The ramp or slope (often called a scarp) formed in an earthquake.What likely happened?

Pull-apart forces pulled the rocks apart, making the break, and allowing one side to drop relative to the other.

What tectonic setting is primarily responsible for producing the Appalachian Mountains and Great Smoky Mountains National Park?

Push-together Obduction

What tectonic setting is primarily responsible for producing Mt. St Helens?

Push-together Subduction

The arrows point to an interesting feature, high in a road cut in the folded Appalachians of western Maryland.What happened here?

Push-together forces broke a layer during folding and shoved one side over the other side.

The rocks in the above picture sit along the side of the Blue Ridge Parkway in Virginia. The layers started out horizontal, but now are vertical.What happened?

Push-together forces when Africa and Europe ran into the Americas bent the rocks, tipping these up on end.

This is a photo of a road cut through a mountain called Sideling Hill, in Western Maryland.What happened here?

Push-together forces when Africa and Europe ran into the Americas bent the rocks, which later were exposed at the surface by erosion.

What tectonic setting is primarily responsible for producing Crater Lake?

Push-together subduction.

What tectonic setting is primarily responsible for producing Olympic National Park as well as the hills on which San Francisco is built?

Push-together subduction.

Lithospheric plates can interact in many ways at the long boundaries where they meet. Which of the following options includes the main patterns of interaction that are observed along these boundaries:

Push-together, pull-apart and slide-past.

In a humid-temperate climate such as that of Pennsylvania or Washington, DC, weathering breaks down granite to produce:

Quartz sand, clay, and rust, that stay to help make soil, while some ions dissolve and wash away.

In age dating, geologists use:

Radiometric techniques and layer-counting for absolute dating of events that happened in the last 100,000 years, and other radiometric techniques for absolute dating of much older events.

A dam is built on a river, forming a reservoir. Over time, this likely will cause:

Rapid erosion of sand downstream of the dam, because the clean water coming out of the reservoir will be able to pick up the small sand grains.

Reasons why fossils of transitional forms are missing in some lineages that humans especially care about include:

Rapid evolution often occurred in small populations, and fossilization is less likely in smaller populations.

Soil thickness:

Reaches a natural balance between production by weathering and loss by mass movement, and humans have upset this balance, primarily by increasing mass movement so that soils are thinning.

Sometimes, people with scientific backgrounds say bad things about religion, and sometimes people with religious backgrounds say bad things about science. This is because:

Religion and science do not need to disagree, but sometimes science-background and religion-background people choose to disagree.

Fossil fuels are usually formed from:

Remains of formerly living things buried by sediments in regions with little oxygen.

The picture above shows a muddy limestone that was deposited in shallow water of a lake. The pocket knife is sitting on a high region of the rock. The pink arrow points along a low trough or groove in the rock, and several other such grooves are evident. The rock is:

Right-side-up; you are looking at the side that was facing up toward the sky when the rock was deposited.

Hot spots:

Rise from as deep in the mantle as the core-mantle boundary to the surface of the Earth, bringing up heat and feeding volcanoes.

Geologically speaking, the water table:

Rises during or soon after rainstorms as spaces fill up, and sinks during droughts as water drains away.

Globally averaged, the level of the oceans is:

Rising, as warming causes the ocean to warm and expand, and as glaciers melt.

What happened in the picture above?

Rivers have delivered sediment to the sea, forming deltas that built up as they built out so that they still slope slightly downhill toward the sea.

You decide to get "back to nature", so you dig a well in your back yard in the limestone rocks there, install a hand pump, and pump the water from your well into a basin to which you add a little soap when you want to wash dishes. After a while, you notice white scum on your glasses, which gets worse and worse with time. This probably is:

Rock that had been dissolved in the water, and that probably is building up inside your pump and elsewhere as well.

Geophysical evidence indicates that convection is occurring in the Earth's mantle. What is the most likely physical explanation for why convection can occur in the mantle?

Rocks deep in the Earth expand and so become lower in density and tend to rise as they are heated, and the deep rocks are warm enough to flow slowly even though they are mostly solid.

You drill through the muds at the bottom of the sea floor and sample the rocks beneath, and you then determine the ages of those rocks, using standard scientific techniques. As described in the course materials, you will find that:

Rocks farthest from spreading ridges are oldest, with ages decreasing as you move toward a ridge.

When discussing earthquakes that happen in the upper part of the Earth's crust, geologists believe that most are caused by elastic rebound. This means:

Rocks on opposite sides of a break, or fault, move in opposite directions, get stuck against each other for a while, bend, then "snap back" when something breaks or gives along the fault.

During weathering, iron in minerals typically:

Rusts, becoming part of the soil, later to be transported as solid particles to contribute to sediment in the ocean.

What is accurate about seismic waves moving through the Earth?

S-waves (also called shear-waves) move through solids but not liquids.

The two pictures above, I and II, show fossils inrocks from the Grand Canyon. Each is "typical"; the rocks near sample Icontain fossils similar to those shown in sample I, and the rocks nearsample II contain fossils similar to those shown in sample II. It is likely that:

Sample I is from high in the cliffs of the Grand Canyon, and sample II is from much lower, near the river.

Humans often try to change coastal processes to benefit us. One of the many things we do is to build walls, or groins, or jetties, to interrupt waves and currents and sediment transport. This example is from the coast of Washington.What has happened here?

Sediment transport is typically from the right, causing deposition to the right of the jetty but erosion to the left

In the picture above, the yellow arrow points at a jetty, a sort of sea wall or groin or dam, that was constructed along the coast of Washington.A likely interpretation of what you see here is:

Sediment transport is typically from the right, causing deposition to the right of the jetty but erosion to the left

Acadia is beautiful even in the rain and fog, but the park still doesn't have many sandy beaches, and this is surely not a sandy beach, the rocks are granite, broken off the granite bedrock. Why aren't there sandy beaches?

Sand is produced or supplied slowly enough, and sand loss to deep water is fast enough, that sandy beaches do not form.

Sometimes, science and religion come into conflict. This is because:

Science and religion can coexist just fine with a little effort, but sometimes choose not to do so.

Opinion polls show most residents of the US do not believe they understand science very well, but they do favor more government support of science. Why do most US residents favor government support of science?

Science has helped make our lives healthier, wealthier, easier, safer, etc., and people hope that more funding of more science will provide even more health, wealth, ease, safety, etc.

Years may pass with no major damage to the US mainland from hurricanes, but other years bring huge damages. A terrible event happened in 2005, when levees around New Orleans failed in the rising waters of Hurricane Katrina. More than 1400 people died, and the damages were in the neighborhood of $300 for each person in the US, or about $100 billion. As discussed in the text, history shows that:

Scientists and serious planners had warned about such an event for decades, based on the known size of hurricanes and the sinking of the Mississippi Delta and much of New Orleans.

What is more accurate about the Earth?

The Earth is formed of concentric layers (something like an onion--a central ball with a shell around it, and a shell around that...); when the planet melted, it separated into layers.

The US government, and most other governments of the world provide support for scientists but not for astrologers, palm readers, or telephone "psychics". Why do governments support scientists?

Scientists help humans do useful things, which makes the humans healthier, wealthier, etc., and governments often like to support health and wealth.

The picture above is of the coast at Acadia National Park. Look at the shape of the rocky island marked with the big "I" in the middle of the picture.The most likely interpretation is that this was caused primarily by:

Sculpting of the rocks by a glacier, which flowed from the left to the right.

On average around the world:

Sea level is rising, as warming causes ocean water to expand, and glaciers to melt.

Most U.S. beaches are shrinking or encroaching on the land rather than growing or moving seaward, so the land of the U.S. is getting smaller, not bigger. Causes include:

Sea-level rise as the last ice age ended flooded river valleys to form bays, and sediment now is deposited in these bays rather than being delivered to beaches

In the picture above, the big W is in ocean water, while the little w is in water in a bay cut off from the ocean by the bar indicated by the pink dashed arrow. A stream flows toward the bay along the blue arrow, and coastal bluffs are indicated by the dashed yellow arrow.What probably happened here?

Sediment has been eroded from the land by waves crashing against the bluffs, and the sediment has been transported along the shore by longshore drift to build the bar.

Think about Pennsylvania, or other places in the eastern US. What is accurate:

Sediment is accumulating in a few places, with erosion in most places, and this has been the pattern for a long time, so the geologic record in any township or similar-sized area is notably incomplete, and you need to combine observations from many places to get a reasonably complete geologic record.

What is accurate about the land surface today, that you can observe in places such as Pennsylvania?

Sediment is being deposited in a few places, but most places are eroding.

Often, building a groin or "dam" sticking out into the water from a coast in a region where longshore drift is moving sand from "upstream" to "downstream" only partially solves the problem for which the groin was designed, because:

Sediment is deposited upstream of the groin but eroded downstream of the groin.

How is sediment related to sedimentary rock?

Sediment is gradually hardened to sedimentary rock by various processes, and the point where the name changes from sediment to sedimentary rock is somewhat arbitrary.

Which of these is an important idea that geologists use in learning which clastic sedimentary rocks are older, which younger, and what has happened to those rocks?

Sedimentary layers start our nearly horizontal.

A dam is built on a river, forming a reservoir. Over time, this likely will cause:

Sedimentation to bury farmer's fields upstream of the reservoir, and erosion of sand downstream of the dam.

Geologic history involves learning the order of events in the past (which came first?), and, what happened. Part of "what happened" is reconstructing what the environment was like in the past. What is accurate about the human effort to learn about past environments?

Sediments and sedimentary rocks provide much information about whether they were deposited in the ocean or on land, whether the climate was hot or cold and wet or dry, and more.

Geologically speaking, the water table:

Separates the water-filled region below the Earth's surface from the region closer to the surface in which some air exists in the spaces.

Evidence that there was much more land ice about 20,000 years ago than there is now includes:

Shells of creatures that lived in the ocean about 20,000 years ago indicate that the ocean water was especially isotopically heavy then.

Which is not evidence that glaciers were much bigger about 20,000 years ago than they are now?

Shells of creatures that lived in the ocean about 20,000 years ago indicate that the ocean water was especially isotopically light then.

Sandy beaches:

Shrink if the sand supply from rivers or coastal erosion is smaller than the sand loss to deep water, and grow if sand supply exceeds the sand loss, remaining in balance if sand supply equals sand loss.

What tectonic setting is primarily responsible for producing the great San Francisco earthquake and the San Andreas Fault?

Slide Past

Slide-past (or transform, with horizontal but no vertical movement) earthquakes and faults such as the San Andreas.

In childhood stories (such as Little Red Riding Hood), we humans worry about predatory mammals such as wolves or tigers rather than worrying about predatory dinosaurs such as allosaurs or tyrannosaurs. This is because:

Small mammals coexisting with the dinosaurs were not able to outcompete the dinosaurs for big-animal jobs, but after the dinosaurs were killed, some large mammals evolved from small mammals to fill the large-animal jobs, including the big-predator job.

There are many large mammals on Earth today. This is because:

Small mammals were not able to outcompete the dinosaurs for big-animal jobs, but after the dinosaurs were killed, some large mammals evolved from small mammals to fill the large-animal jobs.

In the picture above, the pink and yellow arrows in front of Dr. Alley point to two rather different deposits from an eruption of the Hawaiian Volcano Kilauea. As described in the class materials, these materials are:

Small pieces thrown through the air, and frozen "waterfalls" of lava that flowed quietly before freezing.

Mass wasting delivers sediment to streams. We believe that in regions such as Pennsylvania or the hills around Washington, DC, most of the mass that is delivered to streams arrives by:

Soil creep, slow motion of pieces from freeze-thaw action, throw by falling roots, downhill motion of rocks during digging of gopher holes, etc.

In the Great Smokies:

Some older rocks were shoved on top of younger ones by push-together thrust faulting.

Before they can be published, scientific papers must be peer-reviewed. This means that:

Some other scientific experts read the papers and provide quality control by eliminating many mistakes.

What causes the great majority of earthquakes?

Stick-slip behavior across faults

What is accurate about the scientific results learned by counting tree rings?

Study of tree rings and associated geology shows that the Earth is more than 12,429 years old.

The stiff basaltic rocks of the sea floor are bent as they enter subduction zones. This means that:

Subduction zones produce sea-floor trenches, which may be filled with water or with sediment washed from nearby land.

Beaches change as seasons progress. A typical change is (note: a breaking wave curls over and the top falls down, making spectacular movie footage if a surfer is in the way; a surging wave hangs together and the top doesn't fall over):

Surging waves bring sand in during summer, and breaking waves take sand out during winter, so summer beaches are large and sandy while winter beaches are small and rocky.

Suppose that CO2 in the atmosphere was held at a constant, natural level for a few thousand years. Then, CO2 was added to double the atmospheric level rapidly, and this new, doubled level was maintained for a few thousand years. What was the most likely change in the typical average temperature of the planet?

Temperature after the increase in CO2 was a few degrees higher than temperature before the increase.

What is not accurate about the "Law" of Faunal Succession:

The "Law" was developed by Darwin to help his geological colleagues put rocks in time order.

What is not accurate about the "Law" of Faunal Succession:

The "Law" was developed from evolutionary theory to allow fossils of formerly living things (fauna) to be placed in order or succession based on their characteristics, and this in turn allowed early geologists to figure out which rocks were older and which younger.

What is accurate about the "Law" of Faunal Succession:

The "Law" was developed from the observation that using geologic reasoning to put rocks in order from oldest to youngest also put the fossils in those rocks in order.

The Earth has a fascinating history, which this class has just begun to explore. Which is more nearly correct, according to the scientific interpretation presented in the text?

The Earth formed about 4.6 billion years ago, well after the Big Bang, as materials made in stars fell together to form the planet.

The scientific study of the origin of the planet has taken a lot of effort, and still generates much discord outside the scientific community although almost no discord within the scientific community. The scientifically accepted history is:

The Earth formed from older materials that fell together under gravity about 4.6 billion years ago.

Geologists get to play with chemistry, physics, biology... and history! And what a history you will meet as you work your way through the course. Starting at the beginning, the textbook provides the scientifically accepted start of the story... and promises that you'll get to explore some of the evidence for that scientific view, later in the semester. Meanwhile, which is more nearly correct of the scientifically accepted view?

The Earth formed from the falling together of older materials, about 4.6 billion years ago.

The Earth is layered. Most geologists believe that this layering originated primarily because:

The Earth is layered. Most geologists believe that this layering originated primarily because: The Earth partially or completely melted soon after it formed, and the denser materials fell to the center.

We humans are changing the composition of the atmosphere in many ways. Those changes will directly affect the planet's temperature, but the resulting change in temperature will affect other things on the planet that also affect the planet's temperature. Suppose that we could magically change the composition of the atmosphere enough to raise the temperature one degree if all other parts of the Earth system were held fixed, and after the warming, we allowed the other parts of the Earth system to react for a few years or decades. At the end of that time, what would be the total change in the Earth's temperature?

The Earth would end up a few degrees warmer than before the human influence, because positive feedbacks would amplify the original change.

We humans are on track to increase the amount of CO2 in the atmosphere so that the concentration in the future more than double the atmospheric CO2 concentration that existed for the few millennia before the industrial revolution. If we could cause just a doubling and then hold the CO2 level constant at that doubled level for the next thousand years, we very likely would see:

The Earth would warm a few degrees, and then the temperature would stabilize at that new, warmer level.

The top picture from the coast of Greenland, and the bottom picture from Bear Meadows Natural Area in central Pennsylvania, are geologically related. How?

The Greenland picture shows rocks that have been creeping downhill on permafrost, and Bear Meadows probably was formed when such a creeping mass dammed a stream during the ice age.

In the picture above, when Dr. Alley slices his finger through the sand, he is recreating on a smaller scale what type of geologic process?

The action of mass wasting, as soil and rock collapses off of newly steep canyon walls initially carved out by water.

Your boss has assigned you to get the low-down on the latest wonder-drug, and to be darn sure to get it right.You would be wise to consult:

The article in the Journal of the American Medical Society, a peer-reviewed scientific journal, reporting on the discovery and testing of the drug.

Which is accurate about the Earth?

The asthenosphere is the soft part of the mantle below the lithosphere. The lithosphere is a layer containing both the uppermost part of the mantle and the crust, where breaking is more common than flowing.

Beaches change size with every storm, but if you average over a few decades, the size of a typical sandy beach is usually controlled by:

The balance between sand loss to deep water, and sand supply from rivers or from coastal erosion.

The size of a typical sandy beach, averaged over a few decades, is usually controlled by:

The balance between sand supply from rivers or from coastal erosion, and sand loss to deep water

People sometimes take machines out into deep water to "mine" sand, and bring it back to beaches. Dumping a lot of new sand on a beach usually causes:

The beach to lose the new sand over the next year or years, as waves and currents move the sand back to deeper water.

What happens to most of the water that falls as rain on central Pennsylvania's Happy Valley each year (or any similar place, such as Washington, DC or other places with trees)?

The biggest amount is re-evaporated, mostly through trees, and most of the remainder soaks into the ground and then flows through the ground to streams.

which is not accurate about the grand canyon, in arizona?

The canyon is wider at the top and narrower at the bottom because the river was wider when the region was wetter, and has narrowed as deserts spread recently.

The dam has trapped sediment upstream, and the clean water coming over the dam has picked up sediment downstream of the dam and lowered the stream bed there.

The map above shows the Birdfoot Delta of the Mississippi River, where it empties into the Gulf of Mexico. The river is shown in blue, as is the Gulf of Mexico. The river "wants" to leave this delta, and flow somewhere else, far to the west of the area covered by this map.Why?

The delta has built up as well as out, and that makes some other path to the Gulf steeper and shorter than the one now being taken, and during a flood the river tends to take that shorter path and cut a new channel.

Melting happens in association with a subduction zone. What is going on to cause this?

The downgoing slab takes along water, and that water lowers the temperature at which rock melts to allow melting in and near the slab.

Volcanoes occur above the downgoing slab of a subduction zone. Why?

The downgoing slab takes water and other things along, which lower the melting point down there enough to make melt that feeds the volcanoes.

The picture above illustrates what scientific principle?

The equator is hotter than the pole because the sun hits the equator directly but the sun hits the pole a glancing blow

On the left, red rocks deposited in a lake extend off to Bryce National Park. On the right, black lava flows, now cooled and hardened, are visible. The rocks meet at the Sevier Fault. What happened here?

The fault formed during Death-Valley-type spreading in the west, with the younger, black lava flows dropping along the fault to lie next to the older, red lake sediments.

The cartoon above illustrates a specific geologic process. Which of the additional geologic images DOES NOT feature this same process at work?

The folded Appalachians, including the region of central Pennsylvania around Penn State's University Park campus, shown in the satellite image here, as well as the Great Smokies and the Blue Ridge, formed when Africa and Europe collided with the Americas, much as the two cars in the picture collided. Crater Lake records different processes.

A glacier does flow "downhill". Which is correct about the hill?

The glacier flows from where its upper surface is high to where its upper surface is low, and thus flows down the hill of the ice surface.

The picture above shows a glacier in eastern Greenland, in the world's largest national park, flowing from mountains at the top of Jameson Land (at the top of the picture) toward the lowlands of Kong Oskar Fjord (just out of the picture at the bottom).Based on what the picture shows, what has happened over the last century or so?

The glacier has become shorter, because of a decrease in snowfall to the accumulation zone (A) or an increase in melting of the ablation zone (B).

In the photo above, Sam Ascah is standing on sand and gravel in a pothole, where a stream swirls during the short but intense thunderstorms of Zion National Park. And next to that stream, the other picture shows the sandstone and the hang-on-so-you-don't-fall-over-the-cliff chain along the trail. A likely interpretation of these features is:

The grooves behind the chain have been cut over decades by motion of the chain as hikers grabbed it, and the potholes were cut by water swirling rocks around during the rare floods over much longer times.

On the Richter scale of earthquake intensity:

The ground is shaken 10 times more by a magnitude-8 quake than by a magnitude-7 quake.

Air that passes over the Sierra Nevada from the Redwoods to Death Valley is warmed by roughly 30 F, even if the air goes over at night. Where does the energy come from?

The heat that had been stored during evaporation from the ocean and was released when clouds formed on the west side of the Sierra

The picture doesn't even show all of the rock above ground, and there is as much rock below ground as above. Great Rock sits well north along the Cape, just inland of Coast Guard Beach. Most of the Cape there is sand and gravel. So why is the rock there?

The ice carried the rock here—glaciers carry big as well as little rocks, and can leave big ones even if most of the material carried by the glacier is then sorted in outwash.

When a scientist says that a glacier flows, the scientist means that:

The ice is almost warm enough to melt, and deforms slowly like hot iron in a blacksmith shop or a chocolate bar in your pocket.

If you went to Greenland and drilled a hole in the ice sheet, then came back later and surveyed the hole, you would find that the shape of the hole had changed. If you asked Dr. Anandakrishnan why the shape changed, he would tell you that the ice sheet was flowing. He would be correct. What does he mean by this?

The ice is not too much colder than its melting point, and deforms something like hot rocks in the mantle or a chocolate bar in your pocket.

In the picture above, Dave Janesko holds two rocks next to each other. The black one (to the upper left in the picture) is from a lava flow, and is much younger than the red one (to the lower right in the picture), which is a lake sediment. In nature, these rocks are found the way Dave is showing, with the younger black one next to the older red one rather than being on top of the older red one. As described by Dave Janesko in the online video, what happened here?

The lake sediments were deposited, then the lava flowed on top, and then a pull-apart Death-Valley-type fault formed, breaking the rocks and dropping the lava flow to be next to the lake sediments.

In Pennsylvania today (or at most other places on the world's land surface):

The land surface is accumulating sediment in a few small places, building up records of geologic history, but most places are eroding.

Often, landowners along eroding beaches will build groins, which are walls or dams sticking out into the ocean or lake from the beach. Why are these built, and what happens?

The landowners are trying to catch sediment from the longshore drift to add to the beach; this can work, but often erosion on the "downstream" side of the groin makes the neighbors mad.

Look at the picture above. Here is new land forming in Hawaii, where lava enters the sea. What is happening here?

The lava flow has cooled on the sides and is draining out the middle. Eventually, if more lava is not supplied at the other end of the tubes to replace the lava that is draining out, the lava tubes may empty and leave caves.

What is accurate about a typical volcano formed by eruptions from a hot spot?

The lava of the volcano is mostly basaltic in composition, with gradual sides where the volcano projects above sea level, but steeper sides on undersea portions.

Which is accurate about the Earth?

The lithosphere normally breaks, and the asthenosphere normally flows.

Which is accurate about the Earth?

The lithosphere usually breaks rather than flows, and the asthenosphere usually flows rather than breaks.

The big W is in ocean water, while the little w is in water in a bay cut off from the ocean by the bar indicated by the pink dashed arrow. A stream flows toward the bay along the blue arrow, and coastal bluffs are indicated by the dashed yellow arrow.What probably happened here?

The low bluffs show that erosion has been occurring as waves hammer the shore, and the bar shows that longshore transport is moving the sediment from that erosion along the shore.

It is almost always interesting to ask whether most of the "action" comes from the few, rare events, or the many common events. For earthquakes, we saw that most of the energy is released by the few, big events. For mass movement, averaged over the land surface and over thousands of years, which moves the most material:

The many, small events (often lumped together as soil creep) move the most material.

What type of mass movement moves the most material, averaged over the Earth's land and over long times?

The many, small events move the most material.

Most of the island of Greenland is covered with a great ice sheet, but rocks and soil stick out in some coastal regions, such as the one in this picture in the great Northeast Greenland National Park. The picture above shows a hillslope that is about ½ mile across. The hill slope towards you, so the lowest part of the hill is at the bottom of the picture, and the highest part is at the top of the picture.What is likely to be true?

The materials on the hillside are moving toward you at an inch or so per year.

Dr. Randall Irmis is a famous paleontologist, who has gone on to make important discoveries since he showed the Penn State CAUSE class this fossil plate from the armored vertebrate Buettneria.Based on the discussions in the class materials on the topic of evolution, it is likely that:

The most similar species alive today are related to but recognizably different from Buettneria.

Large rivers have many interesting features, including:

The natural levees, formed when flood waters leaving the channel slow down and drop much of their load near the channel; beyond the natural levees is the flood plain, where much of the rest of the mud in a flood is deposited in a thin layer.

The new idea must explain the things that your old idea explained, and do a better job than your old idea in predicting the outcomes of many new experiments designed by various people to test the ideas.

In chemistry, the type of an atom (what element it is) is determined by:

The number of protons it contains in its nucleus.

The United Nations-sponsored Intergovernmental Panel on Climate Change shared the 2007 Nobel Peace Prize. The information that the Panel has supplied to policymakers includes:

The observed rise in atmospheric CO2 levels has been caused primarily by human fossil-fuel burning, and very likely is causing warming of the climate that is likely to become much larger if we continue our current behavior.

The above Landsat image from NASA shows Cape Cod, Massachusetts.The short yellow arrow indicates new sand deposits, which have formed over the last decades. The long pink arrow indicates underwater sand deposits. The dotted blue arrow points to the great Outer Beach of the Cape.Based on material presented in this class, what is going on?

The ocean is eroding the blue-arrowed outer beach, and the yellow-arrowed end is growing more slowly, with some sand falling off to the pink-arrowed deposits and then off into deeper water, so the Cape as a whole is shrinking.

At Cade's Cove in the Great Smoky Mountain National Park, there is an unusual arrangement of rocks where older rocks are sitting on top of younger rocks, though neither layer has been overturned. This is because:

The older layer was thrust over the younger layer by the forces of obduction.

Which is not accurate about the Grand Canyon, in Arizona:

The oldest rocks are on top, with younger ones beneath, as shown by all of the footprints being upside-down in the rocks of the canyon walls.

What is indicated by the arrows?

The pink arrows point to a barrier beach or outer beach piled up by waves, and the yellow arrows point to a "washover" where a storm broke through the outer beach and moved sediment inland.

Earthquakes can be caused in many different ways. The best interpretation of the planet's earthquakes is that:

The rare, deepest ones are caused by "implosion" as minerals in downgoing slabs of subduction zones suddenly switch to a denser arrangement, whereas common shallower ones are caused by elastic rebound of bent rocks when a fault breaks.

Soil is produced by weathering of rocks. In the natural state of affairs, on a hillside covered by soil:

The soil thickness tends to a nonchanging value as production is balanced by removal, but you may have to watch for a while, as sometimes production may go faster and sometimes removal may go faster.

Dr. Alley once helped a Grand Canyon ranger answer a tourist's question: "Why is the Canyon wider at the top than at the bottom?"The tourist had their own favorite theory. Based on the materials that have been presented to you've in this class, what geologically accepted answer would Dr. Alley and the ranger have given the tourist?

The river cuts down, and that steepens the walls of the canyon, which fall, topple, slump, creep or flow into the river to be washed away, thus widening the canyon above the river.

Stephanie and Topher are standing next to the Colorado River in the Grand Canyon. What can be said of the water here?

The river was naturally muddy, but has been made clear because most of the sediment is settling out in the reservoir behind the dam upstream.

The picture above shows a very hard piece of rock about six inches across, in the Grand Canyon.The surface of the rock looks rather different from the surfaces of many other rocks.What made this odd-looking surface?

The river, which blasted the rock with sand- and silt-laden water during floods; this shows that even hard rocks can be eroded by rivers.

Shown above is Great Rock, Cape Cod National Seashore, with some of Dr. Alley's relatives for scale. The rock is metamorphic. The picture includes most but not all of the above-ground portion; the rock goes about as far below ground as above. What is the rock doing here in the middle of Cape Cod?

The rock was carried here by glacier ice and left when the ice melted.

The picture above shows an outcrop along Interstate 70 in Utah. The green arrow points to a person, for scale. The pink arrows pointto the ends of an interesting surface. Some rocks are below this surface, and other rocks above it. What happened to make this outcrop?

The rocks below were deposited, hardened, turned on end, eroded to make an unconformity with a soil developing on top, and then other rocks were deposited on top of the soil.

Pieces of bedrock from Canada are spread across large areas of northwestern Pennsylvania, even though the Great Lakes are between Pennsylvania and Canada. How do geologists explain this?

The rocks were carried into Pennsylvania by a glacier flowing from Canada; the base of the ice was able to flow uphill from Lake Ontario into Pennsylvania because the top of the ice sloped down toward Pennsylvania.

Suppose you wrote a big check to someone to go out into deep water and haul sand up to replenish your private beach along the Atlantic coast. What is this most likely to cause?

The sand will be moved back into deeper water by waves and currents over the next year or years.

A scientist successfully predicts the outcome of an experiment. You watch carefully and know he didn't cheat. The scientist's success shows that:

The scientist may know the truth, or at least know something that is close to the truth, or the scientist may have gotten lucky this time; you can't be absolutely sure

Dave Janesko is explaining the great Sevier Fault to Dr. Alley and the CAUSE class. [See image: UNIT 2.1]Dave has just informed everyone that the black rocks, which formed by cooling of a very hot lava flow, are much younger than the red rocks, which formed from sediments deposited in a lake. He has examined the red rocks and found that they have not been "cooked" by heat from the black rocks, so the red and black rocks must have been placed together after the black rocks cooled. And, he has examined the contact between red and black rocks and found that it is a fault that has been scratched by the motion of the rocks along the fault. It is likely that:

The scratches are nearly vertical, because the black rocks were dropped down along a pull-apart fault to lie next to the red rock.

Sea level can change locally for many reasons, but averaged over all of the oceans of the world:

The seas are rising, because warming is causing the ocean water to expand and mountain glaciers to melt.

In the image above, a stream from the land on the right enters the ocean on the left in the lower part of the picture, and another does the same near the top of the picture. What happened where the streams met the ocean?

The sediment carried by the streams settled out in the slower-moving ocean water, forming deltas that built up as they built out so that they still slope slightly downhill toward the sea.

Dust and shells and fish poop and all sorts of things fall to the sea bed to make sediment. Across broad central regions of the ocean, the sediment accumulates at a uniform rate—piling up about as rapidly here as it does over there. And, in most places, the currents don't move the sediment around much, so that it stays where it falls. Thus, the thickness of the sediment is related to the age of the rocks beneath the sediment. If you go around an ocean and measure the thickness of the sediment in lots of places, you are likely to find:

The sediment is thin near spreading ridges, and thicker away from the ridges.

One practical radioactive system used to date lava flows involves:

The solid potassium-40, which decays to the gas argon-40.

The concentration of CO2 in the atmosphere rose as the last ice age ended, and then stabilized for thousands of years, until humans became serious about changing the atmosphere with the start of the industrial revolution. Suppose that we succeed in raising the CO2 concentration in the atmosphere to a level twice as high as occurred for the thousands of years after the ice age and before the industrial revolution, and then we hold the concentration constant at that new, higher level for the next thousand years. What would happen to the average temperature of the planet?

The temperature would increase to a few degrees above the pre-industrial-revolution level, and then stabilize at that new, warmer level.

If you could jump in a time machine and zoom back to when the Earth was only half its current age, you would probably find:

The total area of continents then was smaller than now; continents have grown over time as material scraped off downgoing slabs of subduction zones has been added to the continents.

You are told that you are going to visit a region that was under a glacier for many thousands of years ending about 20,000 years ago, but was near where the glacier ended by melting, so lots of meltwater streams flowed through the glacier to the bed and out the front. What will you probably find in the landscape?

The tracks of the glaciers will be easy to see, although minor modification by streams, wind and mass movement will have started.

What probably happened in the above picture?

The tree started with its roots underground, but erosion washed the dirt away from them, so now they stick out.

You find two neutral atoms. Each has 8 protons in its nucleus, but one has 7 neutrons, and the other has 8 neutrons. It is correct to state that:

The two atoms are from the same element, but are different isotopes of that element.

Most landslides happen when:

The unconsolidated materials on hillslopes are very wet and thus heavy and slippery, and the water doesn't have to "break" as the grains move.

You build and maintain two biologically diverse terrariums that are identical in every way at the beginning, except that one is divided in half by an unbreachable glass wall. After some time (long enough for many generations to pass, but not long enough for much evolution to occur), it is most likely that:

The undivided terrarium will have more species than the divided one.

If you took your helicopter and landed on a mountain peak next to Death Valley, then took off and flew at exactly that mountain-peak elevation out over the valley, and lowered a rope to a person standing on the floor of the valley, you would find that you would need a two-mile-long rope to reach the valley floor. How did this immense difference in elevation come about?

The valley floor dropped downward along earthquake faults by more than two miles relative to the mountain peaks, but rocks eroded from the peaks have been carried down and deposited in the valley, so that the vertical distance from valley to peaks is now only two miles.

The picture above shows river gravels in the bottom of Death Valley.Based on the lesson materials for this unit, a likely explanation for this occurrence of river gravels in the valley bottom is:

The valley was dropped relative to the mountains by faulting, and rivers now are carrying gravels down from the mountains into the valley.

Statistically, and based on how many people are likely to die if they engage in or are exposed to the following problems, which is most dangerous to residents of the United States:

The various diseases that come from smoking, overeating and under-exercising for a long time.

People visit Death Valley for all sorts of reasons. Some people even go there to study volcanoes. What is accurate about those Death Valley volcanoes?

The volcanoes near the edges of Death Valley produce rocks that are similar in composition to the rocks made by volcanoes at undersea spreading ridges, because Death Valley is in many ways geologically linked to undersea spreading ridges.

Suppose that all the rainfall that fell during an average year on a typical surface in central Pennsylvania just stayed there as a layer of water (and all the snow melted, and the melt just stayed there). If at the end of the year you were standing on that surface (assuming you are a typical-sized human being), what would be true? (Pennsylvania gets about the same amount of precipitation as the average for the world.)

The water would be up around your waist or chest, but you'd still be able to breathe.

What is accurate about the planet's climate system?

The wind blows because heating near the equator drives convection cells in the atmosphere, and the winds appears to curve to the left or right over the surface of the planet because of friction produced by the spherical planet's rotation beneath the atmosphere.

The age of rocks near a sea-floor spreading ridge can accurately be described as:

The youngest rocks are near the ridge, and the rocks get progressively older as you go away from the ridge in both directions.

Above is a "beach" at Acadia National Park. The pieces are granite.

There is no sand here, so sand must be lost to deep water fast enough in comparison to sand supply that sandy beaches have not formed.

The photograph above shows some rocks in Great Smoky Mountains National Park.From looking at the rocks, and what you know about the park, a likely story is that:

These rocks were buried deeply and squeezed in a continent-continent collision, and then brought to the surface as overlying rocks were eroded.

Which is most accurate about tsunamis?

They are big waves caused by very rapid displacement of a lot of water, which may occur in response to an undersea landslide, earthquake, volcanic eruption, or other cause.

What is known scientifically about transitional forms in the fossil record?

They are found frequently for those general types of living things (such as shelly shallow-marine creatures) that commonly produce fossils, but are not found as frequently for other general types.

What happens to most living things, after they die?

They are recycled, usually by being "burned" with oxygen to provide energy for other living things, or to provide energy to fires.

Look at the picture above of a small dam across a stream bed (between the pink arrows) just above one of the trails into Bryce Canyon. When floods happen in the stream bed:

They flow toward the camera; floodwaters have filled the space upstream of the dam and debris has started to cascade over the dam, so the dam is not serving to trap sediment any more.

Scientists receive government funding primarily because:

They help humans do useful things

One of the big problems faced by National Parks is that:

They must allow people to enjoy things today, and preserve those things for the future, but achieving both of these is not easy.

High temperature and pressure tend to favor flow rather than breakage, so it is surprising that large, very deep earthquakes are sometimes observed, occurring in warm places where the pressure is high. What is accurate about these rare, deep earthquakes?

They occur at subduction zones, where the rising pressure on rock as it is taken deeper seems to cause "implosion" of minerals as they rearrange to take up less space.

The things that glaciers deposit include:

Till (which is unsorted) and outwash (which is sorted).

Your friend wants to see some real Pennsylvania coals. Where should you send your friend to see coal in the rocks of Pennsylvania (if you honestly are being helpful), and what coals would your friend see?

To the sedimentary rocks of western Pennsylvania to see bituminous, and to the metamorphic rocks of eastern Pennsylvania to see anthracite.

Scientists promote the teaching of evolutionary theory, in part to raise new scientists to help use evolutionary theory. How are scientists using evolutionary theory in efforts that can help people?

Today in Pennsylvania (and across most of the land surface of the planet), sediments are accumulating in a few human-made lakes, a few natural wetlands or natural lakes, along some streams and in some caves, but almost everywhere else is eroding. This is the typical state of affairs, so you need to correlate events across large regions to get a good geologic record.

You are magically able to map where the sand grains go for over a few years on an east coast beach. MOST of the motion is:

Toward and away from the shore with individual waves.

Araucarioxylon arizonicum was a beautiful tree of the Mesozoic, and is the most common tree found fossilized in Petrified Forest National Park. A spectacular specimen is shown above.Based on the discussions of evolution in the textbook and lectures, it is likely that:

Trees alive today are related to Araucarioxylon arizonicum, but even those modern trees most similar to Araucarioxylon arizonicum are recognizably different from it.

Most earthquakes in the upper part of the Earth's crust are caused by elastic rebound, according to geologists. What do those geologists mean when they say this?

Try sliding a boulder over the ground, and you'll find the boulder gets stuck for a while. Lean harder, the boulder jerks forward suddenly, and you just had a tiny earthquake. Implosion earthquakes probably exist, but the rocks don't bounce back to their original size, and such quakes only can happen deep.

John Wesley Powell, who led the first boat trip through the Grand Canyon, called the feature marked by the yellow lines "The Great _________". What did he put in the blank?

Unconformity

Which is older:

Unconformity L

Uniformitarian calculations show that the Earth is more than about 100 million years old, and radiometric techniques tell us how much older.

The picture above shows a muddy sandstone that was deposited on a flood plain. Dr. Alley's index finger in the lower left points along a ridge on the surface of the rock (shadows are to the lower right of Dr. Alley's finger and to the lower right of the feature he is pointing along; his finger is above the rock, so the feature must be a ridge and not a trough). The rock is:

Upside-down; you are looking at the side that was facing down toward the center of the Earth when the rock was deposited.

A nighttime picture of Earth shows human-controlled lights spread across most of the land surface, and a few out in the ocean on ships. In round numbers, humans (and the things we grow, or the pets we live with):

Use almost 50% of everything the world makes available and that we find useful.

The "Law" of Faunal Succession:

Was developed by an engineering geologist to aid in construction projects.

The picture above shows a region of hard rock about six inchesacross from the Grand Canyon. The shape and polish of the rock areinteresting.\ It is likely that the rock:

Was scratched and polished by silt-laden river water, during carving of the Canyon by the Colorado River.

The law that established Yellowstone as the first national park:

Was written to help people today and in the future, by requiring that the parks provide enjoyment today while preserving the parks for the future.

In the picture above, Dr. Alley is on the South Rim of the Grand Canyon. What problem with the Canyon is he discussing?

Water is being pumped out of the ground on the plateau south of the Canyon, and used by humans and evaporated or dumped in streams, so the water does not flow to the springs in the Canyon.

In the picture above, Dr. Alley is discussing events that are happening outside of Grand Canyon National Park, which may impact the park. What are the issues he is discussing?

Water pumped out of the ground for golf courses and other uses evaporates, so less water flows through the ground to the springs of the canyon.

Large rivers sometimes have natural levees because:

Water slows and deposits sediment as the water leaves the main river channel during floods.

Much melting in the mantle occurs near subducting slabs primarily because:

Water taken down subduction zones lowers the melting temperature in and near the slabs.

Old, cold ocean floor sinks at subduction zones. Why does this cause melting to feed volcanoes?

Water taken down subduction zones lowers the melting temperature in and near the slabs.

In the photo above, the jetty (which is a big wall, and could also be called a groin) was constructed out from the coast in the state of Washington. The water is shallow very close to the jetty, and deeper as you move away to left, right, or off the end of the jetty at the lower right.

Waves go slower in shallower water.

The great scientist Alfred Wegener proposed that continents have moved, while other scientists such as T.C.Chamberlin argued against Wegener. Wegener's ideas eventually won, and are now widely accepted, because:

Wegener's ideas did a better job of predicting the results of new observations and experiments.

The mountain range that contains the folded Appalachians, including Mt. Nittany near Penn State's University Park Campus, and the Great Smoky Mountains, was raised to high elevation primarily:

When the proto-Atlantic ocean closed, at a push-together boundary.

In the picture above, the yellow line lies along the contact between sandstone (on the left) and reddish mudstone (on the right). The red arrows point along a place where the sandstone continues into the mudstone. The four sides of the picture are labeled A, B, C and D. What is most likely correct about these rocks?

When the rocks were deposited, side D was the lowest (it was on the bottom).

At the beach, you can build really good sand castles:

When the sand is damp, because water is attracted to sand grains and to other water; thus, pulling sand grains apart when damp requires "breaking" the water, which is not easy.

Which of the following was probably important in contributing to extinction of most species at the same time the dinosaurs became extinct?

Wildfires caused by great heat from rocks warmed by atmospheric friction while falling back to Earth after being blasted high in the atmosphere by the impact.

Can a good geologist ever find a material that is somewhere between sedimentary rock and sediment, loose stuff somewhat stuck together but not really hard?

Yes, because sediment is changed to sedimentary rock by heat, pressure, and hard-water deposits, and intermediates exist.

Can a good geologist ever find a material that is somewhere between sedimentary rock and metamorphic rock?

Yes, because squeezing and heating sedimentary rock makes metamorphic rock, and intermediates exist.

A dam is built on a river that has a river bed that is primarily sand. You have a house just downstream of the dam, and you like to go trout fishing in the river in front of your house. A few years after the dam is built, it is likely that:

You will have built a ladder or steep path to get down to the river, because the clean water released by the dam will have washed a lot of the sand away and lowered the elevation of the river in front of your house.

You are dating a lava flow by the potassium-argon system. However, the offspring in this system are leaking out of the minerals. Which is accurate?

You will think that the lava flow is younger than it really is, but you will be able to detect the error by comparing concentrations of offspring from the edges and centers of grains.

If you could drill a hole straight to the center of the Earth, and keep track of what the hole is going through, you would find:

You would go through one sort of material, and then a different, denser material, and then a still-different, still-denser material, because the planet is made of concentric layers, sort of like an onion.

A 100-foot-high tsunami wave nearly kills you in your boat. It is likely that:

Your boat was in shallow water near the shore, because tsunami waves are usually long and low out in the deep water of the central ocean, but pile up to become high when slowed by the friction in shallow water near the shore.

You develop a new idea, which is in conflict with a widely accepted scientific idea. For your new idea to gain widespread acceptance, you probably will need to show that:

Your new idea does a better job than the previously accepted idea in predicting the outcomes of an interlocking web of important experiments or observations.

Geosc 10 All

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