MasteringGeology HW 04

What is the relationship between water currents and cross beds? Cross beds sit at an angle to current direction. Cross beds sit parallel to current direction. Cross beds sit perpendicular to current direction.

Cross beds sit at an angle to current direction.

Which of the following statements characterizes ephemeral streams? Ephemeral streams don't have any life in them. Ephemeral streams generally depend on groundwater in the desert to flow year round. Ephemeral streams flow all the time in the desert. Ephemeral streams flow only at certain times of the year. Ephemeral streams are streams that flow through deserts, but have their origins outside of the desert.

Ephemeral streams flow only at certain times of the year.

What type of rocks would you expect to find in a playa lake depositional environment? evaporites and claystone poorly sorted conglomerates interbedded sandstones and conglomerates fossiliferous limestone cross bedded sandstone

Evaporites and claystone

What are cross beds? inclined layers in sediment or sedimentary rocks that reveal the direction of wave transport inclined layers in sediment or sedimentary rocks that reveal the direction of wave or wind transport inclined layers in sedimentary rocks that reveal the direction of wave transport inclined layers in sediment or sedimentary rocks that reveal the direction of wind transport inclined layers in sedimentary rocks that reveal the direction of wave or wind transport

Inclined layers in sediment or sedimentary rocks that reveal the direction of wave or wind transport

An isolated, heavily eroded hill or mountain that rises abruptly from a plain is a(n) __________. fault block inselberg alluvial fan playa bajada

Inselberg

In the desert environment, how are ventifacts created? Ventifacts are produced on the surface of a rock by the continued impact of very small particles carried by the wind. Ventifacts are produced by mass wasting when very small particles continue to drop off steep slopes and abrade the underlying rock. Ventifacts are formed as rocks are dissolved by groundwater and the particles produced are removed by wind activity. Ventifacts are produced on the surface of a rock by the continued impact of very small particles carried by running water. Ventifacts are produced by precipitation of mineral matter on the surface of a rock when water evaporates in a desert.

Ventifacts are produced on the surface of a rock by the continued impact of very small particles carried by the wind.

Which of the following statements about deserts is true? Water is the most significant agent of erosion in deserts. Deserts are dominated by sand dunes. Deserts are always hot. Deserts are lifeless. Wind is the most significant agent of erosion in desert regions.

Water is the most significant agent of erosion in deserts.

Most of the erosion that took place during the "Dust Bowl" years of the 1930s in the Great Plains of North America was the result of which of the following processes? livestock herding flooding heavy rainfall wind urban development

Wind

Why do desert dunes migrate? Water erodes material on the back side of the dune and deposits it on the front side of the dune. Wind erodes material on the back side of the dune and deposits it on the front side of the dune. Wind erodes material on the front side of the dune and deposits it on the back side of the dune. Water erodes material on the front side of the dune and deposits it on the back side of the dune.

Wind erodes material on the back side of the dune and deposits it on the front side of the dune.

You are working in a field area that you think at one time contained valley glaciers. What evidence would you look for to determine this? You should see little evidence of mass wasting in the valleys. You would look for rounded, U-shaped valleys. You would look for deep, V-shaped valleys. You should expect a lack of sediment in the area. You would expect to find broad floodplains on either side of valleys.

You would look for rounded, U-shaped valleys.

If all the ice that currently exists on Earth were to melt in the next 300-400 years, which of the following cities would have the least difficulty? Memphis Miami San Diego St. Louis Denver

Denver

Which of the following is true about sand dunes? Dunes move over time. Dunes move as a single bodily mass. Dunes are stationary features. Dunes are more affected by water than wind. Dunes are erosional landforms, not depositional landforms.

Dunes move over time.

Which of the following accurately describes the Basin and Range region of the western United States? a region formed by tectonic extension that includes perennial rivers and extensive channel networks a region with alternating mountains and basins that have been produced by reverse faulting an area with alternating mountains and basins in a humid climate a region with alternating mountains and basins that have been produced by normal faulting a large area characterized by large mountains and rivers that reach the Pacific Coast

A region with alternating mountains and basins that have been produced by normal faulting

Which of the following statements characterize the activity of glaciers and their impact on the landscape? Glaciers are capable of moving large amounts of sediment. Glaciers can disrupt the hydrologic cycle. Glacial activity can change the position of sea level relative to present conditions. Glaciers are capable of oversteepening slopes. All of the responses are valid.

All of the responses are valid.

A(n) __________ is a cone-shaped deposit of sediment that is deposited when a stream exits the mouth of a canyon. playa bajada inselberg alluvial fan dune field

Alluvial fan

Compared with the amount of ice that existed during the last glacial maximum, how much exists today? approximately 1/8 as much approximately 1/3 as much approximately 1/5 as much approximately 1/2 as much approximately 1/4 as much

Approximately 1/3 as much

During the last glacial maximum, the position of sea level occurred at what elevation relative to its position today? At the last glacial maximum, sea level was about 25 meters (~75 feet) lower than it is today. At the last glacial maximum, sea level was about 50 meters (~150 feet) lower than it is today. At the last glacial maximum, sea level was about 10 meters (~30 feet) lower than it is today. At the last glacial maximum, sea level was about 1000 meters (~3000 feet) lower than it is today. At the last glacial maximum, sea level was about 100 meters (~300 feet) lower than it is today.

At the last glacial maximum, sea level was about 100 meters (~300 feet) lower than it is today.

What is cross bedding? Large mound or ridge-like features dominantly composed of sand grains. Sand carried as bed load across the windward side and avalanching down the slip face. Layers deposited on the windward side of a dune that are inclined in the direction of wind transport. Planar layers deposited in low energy, interdune areas. Layers deposited on a dune slip face that are inclined in the direction of wind transport.

Layers deposited on a dune slip face that are inclined in the direction of wind transport.

The __________ of a dune is characterized by a decrease in energy and sand avalanches, which occur due to oversteepening. avalanche leeward side windward side ripple marks gently sloping side

Leeward side

A __________ is defined as a chain of glacial lakes where each lake flows into the next. tarns pater noster lake hanging valleys cirques glacial trough

Pater noster lake

What is the term for the rolling and bouncing of sand grains during transport? suspension traction bed load creep saltation

Saltation

Other than the landforms you learned about in the video, what is another landform present in the Basin and Range Province? deep lakes sand dunes vegetated hillslopes perennial streams integrated drainage networks

Sand dunes

Cross-bedded sandstone shows inclined beds in a downward direction. What part of the ancient dune do these features represent? the whole dune windward side angle of repose crest slip face

Slip face

What do cross beds represent? the orientation of Earth's surface the moving front of a ripple or dune the moving back of a ripple or dune the orientation of the moving Earth's surface

The moving front of a ripple or dune

When desert pavement is produced in a desert, why do the larger particles accumulate on the surface? Wind is capable of moving the large particles to a site where they are deposited. The wind can move particles of only a very specific size and it takes away these small particles, concentrating the larger ones. Particles are cemented together as water evaporates. Running water carries away all the smaller material. Large particles fall from the nearby slopes due to mass wasting.

The wind can move particles of only a very specific size and it takes away these small particles, concentrating the larger ones.

What is the best way to describe the shape of a glacial valley? U-shaped irregular rectangular triangular V-shaped

U-shaped