GEOG 300 Exam #3

Which is a true statement regarding mass movement events (e.g. rockfalls, landslides, mudflows, etc)?

Highly loose and weathered slope materials will significantly increase the likelihood of mass movement events. They are commonly triggered by earthquakes

What its the driving force behind mass movement?

Gravity

Glaciers will tend to form at:

High elevation and high latitude

Which landform is definitely NOT associated with alpine glaciers?

Drumlin

What do large, visible crystals in an igneous rock indicate?

Rock cooled slowly

What type of forces are evident at convergent plate boundaries?

compressional

What type of faulting is shown in this profile (sideview) diagram here?

reverse

Which is an example of an exogenic process?

a river carving though a mountain

at what type of plate boundary might I find reverse faulting?

any convergent boundary

Where is there likely a chain of explosive volcanoes? (You will be shown a map on the exam.)

any subduction zone!!!

the outermost layer of the earth is the

crust

What was the name for Wegener's original supercontinent ?

pangaea

Which of the following sediments are listed in order from largest to smallest? (You will be given the following terms in different orders - sand, pebble, clay, and silt)

pebble, sand, silt, clay

What type of forces are evident at divergent plate boundaries?

extensional

What type of weathering is process that dissolves limestone and marble?

Carbonation

Which type of weathering involves minerals in a chemical reaction with water?

Hydrolysis

Starting at Earth's surface and moving downward, wh at is evident when passing through the Mohorovicic Discontinuity (Moho for short)?

a significant increase in density

At what type of plate boundary might I find reverse faulting?

convergent

If this is an example of a right-lateral strike slip fault (seen from above), which two locations will become adjacent (next to each other) in the shortest amount of time? ( v and y)

v w x ----------------- y z

What is the important function of the asthenosphere?

It is plastic and allows the lithosphere to move over it

Marble, a metamorphic rock, likely originated as what type of rock?

Limestone

Which is an example of an endogenic process?

a volcanic eruption on the ocean floor

What type of moraine forms where two lateral moraines join together?

medial

Where is subduction occurring? (You will be shown a map on the exam.)

at Peru-Chile, Japan, Marianas, and Aleutian Trenches

Which of the following factors is UNLIKELY to cause (or worsen) a mass movement event (landslide, mudflow, etc)?

combined wind and heat

Gneiss, a metamorphic rock, likely originated as wh at type of rock?

conglomerate

Which list of Earth's internal layers is placed in order from highest to lowest density?

core, mantle, crust

Which list of Earth's internal layers is placed in order from lowest to highest density?

crust mantle core

What are the two main components of lithosphere?

crust plus uppermost mantle

A glacial erratic is an example of a/an

depositional landform

At what type of plate boundary might I find normal faulting?

divergent

What characteristic (or characteristics) would you expect to find in a composite volcano?

extremely explosive with steep slopes

What type of faulting is shown in the diagram below?

normal Fault, Reverse Fault, Strike-slip fault (see exam 3 sheet)

In classifying clastic sedimentary rocks, what important quality did we focus on?

size of sediment

What are the classic characteristics of glacial till?

the sediment is Unsorted and UNlayered

Which of these processes is probably most responsible for driving (or causing) tectonic plate movement?

upwelling of magma at divergent boundaries

Which of these processes is probably most responsible for driving (or causing) tectonic plates movement?

upwelling of magma at divergent boundaries

If this is a portion of the San Andreas Fault (seen from above), which two locations will become adjacent (next to each other) in the shortest amount of time? (wz is right)

v w x ----------------- y z

If this is an example of a left-lateral strike slip fault (seen from above), which two locations will become adjacent (next to each other) in the shortest amount of time? ( w z is right)

v w x ----------------- y z

Felsic minerals tend to be

light color, lower density

What is happening to the glacier in the ablation zone?

Snowmelt and icemelt exceed snowfall

Which of the following IS one of the eight most common elements in Earth's crust?

Sodium

where on the ocean floor will I find the oldest rock?

Far from sea floor spreading centers

When studied over time, it was discovered that the center of an alpine glacier will move:

Faster than the side

Which list of intrusive, igneous rocks is placed in order from highest to lowest density?

Periodtite, Gabbro, Diorite, Granite

POSSIBLE ESSAY QUESTION: List and fully explain th e factors which lead to mass movement events (such as rockfalls, landslides, etc).

1.Oversteepening of Slope: Slope refers to a tilted land surface. Above a certain degree of steepness (which depends on what the slope is made of), the slope is said to be overstepped and is prone to mass movement. a) Natural Causes of Oversteepening (i) Mountain Building (ii) Reverse Faulting (iii) Glacial Erosion (iv) Fluvial Erosion (Rivers and Streams) (v) Coastal Erosion (Waves) b) Human Causes of Oversteepening (i) Roadbuilding (ii) Construction 2. Loose/Weak Slope Materials: Loose (or unconsolidated) materials become oversteepened at lower angles, while hard bedrock can maintain stability at higher-angles. Weathering (discussed previously) causes rock to become loose and weak! As such, highly weathered materials are prone to mass movement. 3. Saturation of Slope Materials a) Water lubricates b) Water adds weight 4. Earthquakes and Heavy Construction: Sudden shaking or vibration can initiate movement.

Which land mass was once connected to Gondwanaland?

Antarctica

At which location is a continental rupture (split)occurring? (You will be shown a map on the exam.)

B Africa low

Where is there likely a chain of explosive volcanoes?

B south America

POSSIBLE ESSAY QUESTION: In the future the Atlantic Ocean will likely become larger than the Pacific. Explain this statement and give details and examples.

B. Processes Critical to Understanding Plate Tectonics 1. Sea Floor Spreading (accretion): Magma rises along zones beneath the sea floor. It then splits the plate, fills the new gap, and finally cools, creating new ocean floor made of mostly basalt. Accretion refe rs to the addition of new crust material. The Atlantic Ocean is growing due to this process (e.g. at the Mid Atlantic Ridge). 2. Subduction (consumption): Where one plate dives beneath another and is consumed (melted). Consumption is the subtraction (or destruction) of plate material. The Pacific Ocean is shrinking due to this process. (e.g. at the Peru-Chile, Japan, Marianas, and Aleutian Trenches).

What type are evident at convergent plate boundaries?

Compressional

A chain of volcanoes such as the Cascade Range is formed at what specific type of plate boundary?

Convergent (oceanic vs contiental)

A volcanic island chain such as the Marianas Islands is formed at what specific type of plate boundary?

Convergent (oceanic vs oceanic)

which of following is not one of the eight most common elements in earth's crust ?

Copper

Which is NOT a natural cause of oversteepening?

Effusive volcanic eruptions

Which type of plate boundary will generally have no volcanic activity associated with it?

Transform

For a glacier to form:

Snowfall must exceed snowmelt

Under what circumstances will a lahar most likely occur?

Eruption of an ice covered volcano or heavy rain on a volcano made of lots of loose ash and rock...

Assume that an earthquake with a magnitude of 4.6 and a depth of 14 km occurs in Smithville. Where is the focus of the earthquake?

14 or 13 km beneath Smithville

Much of north America (Canada and North US) was covered by glaciers as recently as ________ years ago.

15,000-18,000

You are on the island of Arewedoneyet. It is a volcano currently forming at an active "Hot Spot" (which means it is zero years old). Approximately 1750km away there is another island, which was formed 18.1 million years ago by the same hot spot. Based on these facts, how fast is the plate moving over this hot s pot?

1750km x 100,00cm/km / 18,100,000yrs = 9.6685

According to most geologists, planetary physicists, widely respected Earth scientists, and your textbook, the age of the Earth is:

4.6 billion years or 4,600,000,000 years

Approximately how fast do lithospheric plates move across the earth?

5 cm/yr

You are on the island of Imsotired. It is a volcano which was formed at a "Hot Spot" 5.7 million years ago. Approximately 650km away there is another island, which was formed 14.7 million years ago by the same hot spot. Based on these facts, how fast is the plate moving over this hot spot?

650km x 100,000cm/km / 9,000,000yrs = 7.222

POSSIBLE ESSAY QUESTION: How does studying the position and age of the Hawaiian Islands help us understand plate tectonics? Provide details.

A hot spot represents a single point of volcanic activity, also referred to as a "stationary mantle plume". As a plate moves across a hot spot, a chain of islands is formed (the Hawaiian Islands is a great example), with the youngest island is over the currently active hot spot, while the older islands have since moved away.

Assuming these rocks have the same size and shape, which one has the least amount of potential energy?

A is at the top of the slop then B C D D is right

Assuming these rocks have the same size and shape, which one has the greatest amount of potential energy?

A is top of the slop then b c d A is right

Which the following was not used as evidence in support of plate tectonic theory?

Global map showing the location of landslides and mudflows Global map showing the location of large continental and mountain glaciers

Which list of extrusive, igneous rocks is placed in order from lowest to highest density?

Greenstone, quartz gneiss galena peridotite

What characteristic (or characteristics) would you expect to find in a shield volcano?

Made of basalt, gently sloped, effusive (quiet) eruptions, thin/runny lava... thin, runny lava and magic minerals

What type of moraine forms where two lateral moraines join together?

Medial

Which land mass was once connected to Laurasia?

North America

What type of weathering involved minerals in a chemical reaction with oxygen?

Oxidation

In which eon (or era, or period, or epoch) do humans live?

Phanerozoic eon, Geologic Epoch: Holocene Geologic Period: Quaternary Geologic Era: Cenozoic

The San Andreas Fault of California is an example of what type of fault?

Right lateral strike slip Fault

POSSIBLE ESSAY QUESTION: Thoroughly compare and contrast the characteristics and results of explosive and effusive volcanic eruptions (as covered in class!!!).

See diagram "VOLCANIC ERUPTIONS AND VOLCANO TYPES OVERSIMPLIFIED" in exam 3 sheet

Which is the best definition of the term "snowline" ?

The elevation line above which snow accumulates. the elevation above which at least some snow remains all year.

Imagine a huge lava flow formed thousands of years ago that is hundreds of feet thick. What will I find?

The most highly weathered material will be at the surface, with evidence of weathering becoming less and less apparent as you drill downward into the rock.