Geology 101, Chapters 8, 11, & 18 Labs & Quizzes

anticline, the limb, the axis

Complete the following statements based on the photo: This fold is a(n): The letter A is located on________ of the fold The letter B is located on the axis of the fold.

volume

Confining pressure causes rocks to change...

growth of new minerals

Consider a diorite (an igneous rock with plagioclase and amphibole) that is metamorphosed into a gneiss. When you look at the gneiss, you can see the minerals quartz, K-feldspar, and muscovite. This tells us that the rock experienced the metamorphic reaction of _____________ during metamorphism.

shape

Directed pressure (differential stress) causes rocks to change...

Compressional Stress

Each tectonic plate boundary is associated with a different kind of stress, based on the way in which the plates are moving relative to each other. Match the type of stress you'd expect to find with the appropriate plate tectonic boundary: Convergent Plate Boundary

Tension

Each tectonic plate boundary is associated with a different kind of stress, based on the way in which the plates are moving relative to each other. Match the type of stress you'd expect to find with the appropriate plate tectonic boundary: Divergent Plate Boundary

Shear

Each tectonic plate boundary is associated with a different kind of stress, based on the way in which the plates are moving relative to each other. Match the type of stress you'd expect to find with the appropriate plate tectonic boundary: Transform Plate Boundary

perpendicular to the direction of directed pressure.

Foliation in metamorphic rocks is always

From oldest: E, D, C, B, A, F

For the figure below, list the rocks (by their letter) in chronological order, with the oldest at the bottom. (Don't forget the dike, F.)

1. The identification of mineral resources. 2. Identifying areas where geothermal energy can be accessed. 3. Helping communities identify and prepare for natural catastrophes. 4. The identification of water resources.

From the video: Geological maps are used for which of the following tasks (there may be multiple correct answers).

1. Pairs of aerial photos 2. By each station where they identify different types of rocks

From the video: Identify two ways in which geologists obtain information about rock types and geologic structures to create geologic maps.

The ages of the rocks.

From the video: What do the colors on a geologic map represent?

The fossil bone is younger than E, but older than C, B, and A.

How old, relative to the other layers, is the dinosaur fossil bone? Hint: fossil bone is second to the last layer

Nonconformity

I already mentioned that rock layer F is a granite, and that layer A is a sedimentary rock (if you look at the Key you'll see that pattern is a sandstone). Given these two rock types, what kind of unconformity is E?

The Principle of Cross Cutting Relationships

In this chapter, you have read about a set of Relative Dating Principles. These are the rules we use to figure out what happened first and what happened next, etc., in a sequence of rocks. Below is a drawing of a sequence of sedimentary rock layers that have been tilted slightly and an igneous dike has intruded the layers. Which of the Principles of Relative Dating would you use to determine if the dike (labeled F) was younger or older than the rock layer C?

Rhyolite #1

Is this felsic ash layer the same age as Rhyolite #1 or Rhyolite #2 from questions 1-4?

5760 feet

(Using Topographic Map 1) What is the elevation of A?

The area around J is steeper because the contour lines on the map are much more condensed signifying a sharp change in elevation.

(Using Topographic Map 1) Which is steeper, the area around J or the area around E? Explain how you can tell from the map.

You are walking downstream because the elevation from I (5700) drops to G (5600)

(Using Topographic Map 1) You take a walk from I to G, along the stream. Are you walking upstream or downstream? Explain how you can tell from the map.

5780 feet

(Using Topographic Map 2) What is the elevation of D?

The elevation change is about 230 ft. Elevation is just a change in height, not about how steep or gentle the slope is.

(Using Topographic Map 2) You walk from A to J: Are you walking uphill or downhill? How much relief (change in elevation) do you experience on the walk?

Regional metamorphism.

A diorite is metamorphosed into a gneiss. This means it was metamorphosed through

skarn

A limestone is metamorphosed by coming into direct contact with a felsic magma. The resulting metamorphic rock will be:

Contact metamorphism.

A limestone is metamorphosed into a skarn. This means it was metamorphosed through

Quartzite

A quartz sandstone is metamorphosed as large quantities of sediment are deposited on top of it. Once the quartz sandstone is buried under 10 kilometers of rock and sediment, it becomes the metamorphic rock:

hornfels

A shale is metamorphosed by coming into direct contact with a hot magma. The resulting metamorphic rock will be

Regional metamorphism.

A shale is metamorphosed into schist. This means it was metamorphosed through

slate

A shale is metamorphosed when it is caught in a mountain-building event, where two continents have collided. The resulting metamorphic rock will be:

235U is the parent isotope. With 71% remaining, only 1/2 of a half-life has passed.

A solidified lava flow containing zircon mineral crystals is present in a sequence of rock layers that are exposed in a hillside. A mass spectrometer analysis was used to count the atoms of uranium-235 and lead-207 (235U and 207Pb) in zircon samples from the lava flow. The analysis revealed the following: 71% of the atoms were 235U, and 29% of the atoms were 207Pb About how many half-lives of the 235U to 207Pb system have elapsed in the zircon crystals?

These streams are flowing north

Locate the streams indicated on this map, in blue. Assume north is toward the top of the map. Are these streams flowing north or south?

The Principle of Superposition

Looking at the same drawing, from question #1, which Principle of Relative Dating would you use to determine whether rock layer A is younger or older than rock layer B?

Disconformity

Match the description with the correct type of unconformity. The boundary between layers of sedimentary rock that are parallel to each other, but are significantly different in age.

Nonconformity

Match the description with the correct type of unconformity. The boundary between an unlayered crystalline rock and an overlying sequence of sedimentary rocks.

angular unconformity

Match the description with the correct type of unconformity. The boundary between sedimentary rock layers that have been tilted and eroded and later horizontal layers deposited on top.

A: alpine type B: andean type C: Cordilleran type

Match the diagram to the correct orogenic type. A: Has the slope going downwards and there is no lava B: Has lava igniting into the volcano

F, E, A, C, M, J, P, G, N, L, R, D, H, B, X, S, O Oldest to Youngest in Order

Now, using the same cross-section, list the remaining letters in order from oldest to youngest. Remember you are starting with F as the oldest and working your way forward in time. Note: My professor changed the letters and covered up the original letters. If the first letter at the top of the image is "O", then these are your answers

The age of the sandstone is between 1.4 billion and 570 million years old.

Now, using this same figure, express the numerical age of the sandstone layer as accurately as possible, by combining the relative ages with the numerical ages on the figure. The age of the sandstone is between_________ and____________

No

Are Rhyolite #1 and Rhyolite #2 (from questions 1-4) the same age?

If there are equal amounts of parent and daughter isotopes, then that means there is 50% of parent, and 50% of daughter. 50% of parent remaining means 1 half-life has passed. The half-life of this system (from the top table of the handout) is 4.5 billion years. 1 half-life x 4.5 billion years = 4.5 billion years. This is the age of the meteorite, and therefore also the age of the solar system.

Astronomers think that Earth formed at the same as all of the other rocky materials in our solar system, including the oldest meteorites. The oldest meteorites found on Earth contain nearly equal amount of both 238U and 206Pb. Using this information and your handout, what is the age of the Earth?

A: Foot Wall B: Hanging Wall Hanging Wall is moving: Down Type of Fault: Normal

Above is a drawing of a dip-slip fault. Match the correct pairs based on the diagram above: Hint: A is higher than B A: B: Hanging Wall is Moving: Type of Fault:

A: foot wall B: hanging wall Hanging wall is moving: up Type of fault is reverse

Above is a drawing of a dip-slip fault. Match the correct pairs based on the diagram above: Hint: B is higher than A

# of half-lives when 6.25% is left- 4 Take the formula t=n*h H=length of half-life, which is 25 million n= # of half-lives, which is 24 t=? So, t= 4* 25 million, which gives us the answer of 100,000,000 of the age of felsic ash.

Another parent-daughter pair is measured in the felsic ash. This pair has a half-life of 25 million years. There is (1/16) 6.25% of the parent remaining. How old is the felsic ash?

The fold axis is plunging, which is shown by the "v" pattern on the map.

Below is a geologic map, with the pattern of a fold in color. Is the axis of this fold plunging or horizontal?

Potassium-Argon Uranium-Lead

If layers C and E were volcanic rocks (lava flows or ashfalls), which of the three isotopic systems mentioned earlier would you be able to use to determine the age of the volcanic rock layers? (You may choose more than one.)

quartzite

If the parent rock is quartz sandstone the resulting metamorphic rock will be

The approximate age of the dinosaur bone would be between 80 to 90 Myrs old.

If volcanic rock layer E is 90 Myrs old, and volcanic rock layer C is 80 Myrs old, what is the approximate age of the dinosaur bone?

5600 feet

On Topographic Map 2, what is the elevation of A?

I used the formula n= t/h In this instance, we don't know what t is, so we're going to multiply n and h together. The half-life is 100,000,000 years. The number of half-lives in question 1 was one. So, I ended up getting, 100,000,000 years of age of Rhyolite #1.

Parent Isotope F in Question 1 has a half-life of 100 million years. Use your answer to question 1 to determine the age of Rhyolite #1.

reverse fault because the hanging wall is moving up.

The fault in the photo above is a: Hint: The first arrow is down and the second is up

Angular unconformity

Using the cross section in the previous question, what type of unconformity is C?

about the same change in both.

Using the gray arrow within the metamorphic field from the graph, a rock metamorphosed during regional metamorphism will experience:

greater change in pressure than temperature.

Using the gray arrow within the metamorphic field from the graph, a rock metamorphosed during subduction zone metamorphism will experience:

The fold is plunging south?

Using the rules and map in the previous question, determine the direction of plunge for the fold.

They all have the same parent rock

What do slate, phyllite, and schist all have in common?

20 feet

What is the contour interval for Topographic Map 1?

marble

calcite-rich and nonfoliated

gneiss

composed of alternating bands of light and dark silicate minerals

Phylitte

represents a grade of metamorphism between slate and schist

# of half-lives when 25% is left- 2 half-lives Take the formula t=n*h H=length of half-life, which is 50 million n= # of half-lives, which is 2 t=? So, t= 2* 50 million, which gives us the answer of 100,000,000 of the age of felsic ash.

One hundred kilometers (60 miles) from Rhyolite #1 and Rhyolite #2, the geologist found an ash layer in the rocks. In order to determine how explosive the volcano could be, the geologist wanted to know if the ash came from the same eruption as either of the rhyolites. A different parent-daughter pair in the felsic ash has a half-life of 50 million years. There is 25% of this parent still remaining. How old is the felsic ash?

E because it's at the bottom

Relative dating gives the ages of rocks relative to the ages of other rocks (e.g., This rock is older than that rock or fossil.) In undeformed sedimentary rocks, the oldest rock layer is found on the bottom, and the youngest rock layer is found on top (Principle of Superposition). The figure to the left is a cross section through sedimentary rock layers. Which layer is oldest?

Rhyolite #1 has 50% of the Parent Isotope F remaining. How many half-lives have occurred? The answer is simply 1. Take 50% and make it into a decimal. Then, you're going to divide it by (log) 0.5. That's how I got my answer.

Rhyolite #1 has 50% of the Parent Isotope F remaining. How many half-lives have occurred?

The answer is 2 half-lives. How did I get my answer? Convert 25% to (Log) 0.25. Then, divide it by (Log) 0.50.

Rhyolite #2 has 75% Daughter G and 25% Parent H. How many half-lives has the rock gone through?

A was deposited directly on top of F, so it is younger than F.

So, now we know that F is the oldest layer in the drawing above. Which of the following layers is the next layer of rock that was deposited, after F?

Correlate rocks that are physically separated by large distances.

The Principle of Lateral Continuity allows geologists to

anticline and horizontal

The block diagram below illustrates a block of the crust, with rock layers indicated by different colors. Complete the statements, based on the block diagram below: The fold is a: The fold axis is a:

anticline and plunging

The block diagram below illustrates a block of the crust, with rock layers indicated by different colors. Complete the statements, based on the block diagram below: The fold is a: The fold axis is a:

can not

The carbon-14 system [ Select ] ["can", "can not"] be used to date dinosaur fossil bones because dinosaurs lived between 65 and 245 million years ago.

normal fault because the hanging wall is moving down.

The fault (indicated by the white dashed line) in the photo above is a: Hint: A man is standing under the wiggly line that is going from top to bottom

normal fault because the hanging wall is moving down.

The fault in the photo above is a: Hint: It's the one where there's a lady standing underneath the normal fault Hint 2: The first arrow is up and the second is going down

recumbent

The fold above is: Hint: it's going in an almost zig-zag pattern

anticline

The fold above is: Hint: the pattern of the rock is going in a downwards slop direction

Syncline

The fold above is: Hint: the pattern of the rock is going in an upwards motion

We're gonna use the same formula- n=t/h However, we need to determine the time. Instead, we're gonna use t=n*h Multiply 2 and 200,000,000 together. The length of the half-life (h) is 200,000,000 years. The number (n) of half-lives in question 2 was two. So, I ended up getting, 400,000,000 years of age of Rhyolite #2.

The half-life of Parent H/Daughter G in Question 2 is 200 million years. Use your answer to Question 2 to determine the age of Rhyolite #2.

The map shows a syncline because the dip symbols are pointing toward the axis of the fold. The map shows a syncline because the youngest rocks are in the center.

The map below has strike and dip symbols which can help you determine if it is an anticline or syncline. Additionally, the green rock layer is the youngest rock layer. Using the rules above, this information can also help you determine if this is an anticline or syncline. Choose the two correct statements about this map from the choices below.

limestone

The metamorphic rock marble is made from the parent rock

shale

The metamorphic rock phyllite is made from the parent rock

subduction zone metamorphism

The name of the metamorphic environment that involves mountain building, where large areas of continents are metamorphosed by the collision of two continents is

contact (or thermal) metamorphism

The name of the metamorphic environment that involves rocks of the ocean floor being subducted is

burial metamorphism

The name of the metamorphic environment that involves ten kilometer-thick layers of additional sediment and rocks being deposited on top of a rock layer is

regional metamorphism

The name of the metamorphic environment that involves ten kilometer-thick layers of additional sediment and rocks being deposited on top of a rock layer is burial metamorphism .

can not, volcanic rocks

The potassium-argon system [ Select ] ["can", "can not"] be used to date dinosaur fossil bones because it is only useful for_______________

When the planar and linear minerals in the rock are aligned with each other, giving the rock a layered look.

The texture that is developed in some metamorphic rocks that form under directed pressure (differential stress) is called foliation. Foliation is

Elastic, ductile and brittle deformation

The three types of strain are

compression, tension, shear

The three types of stress are

large lake bed

There is a large area made up of the metamorphic rock schist. What is the most likely paleo-environment for this rock?

Nonconformity

There is an unconformity marked on the drawing above (dark black line), between the bottom layer (a granite) and the gray layer above it. The granite is a crystalline rock. The gray layer of rock is a shale (a sedimentary rock). Use the rocks types to determine the type of unconformity.

Left-lateral

This photo is of a strike-slip fault: Which type of strike-slip fault is this? Hint: Crop pattern seems to be more to the left

Student 2: The bone is between 80 and 90 million years old. You can't be more specific because you can't determine how fast the layers in this stratigraphic section were deposited.

Two students are debating the age of the dinosaur bone. Which student is correct?

Disconformity

Using the cross section in the previous question, what type of unconformity is D?

a greater change in temperature than pressure.

Using the gray arrow within the metamorphic field from the graph, a rock metamorphosed during contact metamorphism will experience:

Answer 1:K was cut by the fault S. Answer 2:the erosion surface (unconformity) R. Answer 3:the sandstone layer X was deposited. Answer 4:the rock layer A was deposited. Answer 5:the rock layer P was deposited. Answer 6:the rock layer G was deposited. Answer 7:the dike F intruded. Answer 8:the erosion surface (unconformity) C. Answer 9:the rock layer M was deposited. Answer 10:the rock layer H was deposited. Answer 11:the rock layer O was deposited. Answer 12:the fault L cut through. Answer 13:the erosion surface (unconformity) N. Answer 14:the rock layer E was deposited. Answer 15:the erosion surface (unconformity) Z. Answer 16:the rock layer D was deposited

Using the same steps that you used in the previous questions, determine the chronological order of events for the stratigraphic section below. To get you started: both B and K are at the bottom. Notice that a piece of B is inside K. The principle of inclusion tells us that a piece of rock included in another rock must be older than its host rock. Therefore, B is the oldest rock, and K happened next. What happened directly after K?

1/2 of a half-life has passed, and the specific half-life for this isotope pair is 713 million years. Therefore the age of the lava flow is 1/2 x 713 million years = 356.5 million years.

What is the absolute age of the lava flow based on its zircon crystals? (In the previous question you determined how many half-lives have passed, and in the top table of the handout, you can find the half-life of this specific isotope system: 235U - 207Pb.)

Compressional

What type of stress can cause folding?

Angular Unconformity

What type of unconformity is shown in this figure?

recrystallization

When looking at the quartzite, you notice that the quartz crystals are larger than the quartz crystals in the quartz sandstone parent rock, and the crystals in the quartzite have an interlocking pattern. This tells us that the rock experienced the metamorphic reaction of ___________ during metamorphism.

The angles of the layers above and below the unconformity.

Which of the following information helped you identify the type of unconformity in the previous question?

Skarn, Quartzite, and Marble

Which of the following rocks are non-foliated? (Choose all that apply.)

Blue

Which set of arrows (red or blue) best represents the direction of maximum differential stress (directed pressure)? (Hint: which arrows squeezed hardest?) Hint 2: Red arrows are on the side and blue arrows are on the top and bottom

Ductile & Brittle

Which two of the types of strain cause permanent deformation of the rock?

Convergent plate boundaries

Which type of plate tectonic boundary will contain folded rocks?

geologic map

a graphic representation of the geological architecture both above and below ground.

schist

foliated and composed dominantly of medium-to-large platy grains

there is a greater change in temperature than pressure.

in Hydrothermal metamorphism on the graph below (circled in red), which of the following descriptions correctly describes the path of the gray arrow within the hydrothermal metamorphism field?