Geology Test 3
A stream begins at an elevation of 200 meters and flows a distance of 400 kilometers to the ocean? What is the average gradient?
0.5 m/km
Which of the following statements about deposition and erosion around meander loops is true
Deposition occurs where water is moving the slowest along the inside of the loop; Erosion occurs where water is moving the fastest along the outside of the loop.
Double-click the Drainage Pattern F placemark. Which type of drainage pattern is this?
dendritic drainage
Excessive groundwater withdrawals can cause ________
the water table drops or declines in elevation
What is the stream gradient of the Arkansas River between the two placemarks in the Stream Gradient folder?
7.22 meters/kilometer Submit
Which one of the following statements correctly describes how stream terraces can form?
A temporary base level is eliminated; the stream downcuts upstream from the old temporary base level, and the former floodplain is left well above the present elevation of the stream.
Which portion of the stream is the most likely to become an oxbow lake in the near future?
An oxbow could form if the two cut banks at the end of section D eroded all the material in between.
Which of the placemarks in the Stream Types folder represents an ephemeral stream?
B
Which of the labeled placemarks in the Floodplain Landforms folder would have the highest active rate of deposition?
D
What is the relationship between drawdown and the cone of depression associated with a pumping well?
Drawdown is the distance between the original water table and the water level in the well
Which of the following placemarked locations in the Davis' Geomorphic Cycle folder best illustrates Davis' idea of an old age landscape?
E
Which one of the following is not a speleothem?
Geyserite
________ are characteristics found in all good aquifers
High porosity and high permeability
Which one of the following best describes how urbanization affects small-stream watersheds?
Infiltration decreases; lag time between storms and peak runoff shortens
How many stream terraces can exist along a single valley?
No limit exists. Stream terraces will keep forming as long as lateral erosion and downcutting continue
At which of the following locations is erosion occurring?
Points A, C and E all represent cut banks, or locations along a meandering stream where erosion occurs.
At which of the following locations is deposition occurring?
Points B and D represent point bars, or locations along a meandering stream where deposition occurs.
Which one of the following statements is correct?
Sea level drops when water is stored in expanding ice sheets and continental glaciers
Which of the following was a major factor leading to the Gros Ventre, Wyoming, slide?
Soils and shallow bedrock were very wet and locally saturated
Are stream terraces depositional or erosional landforms?
Stream terraces can be either depositional or erosional.
generally constitutes the highest percentage of the annual sediment load moved by a stream
Suspended load
Which of the following can logically be concluded by speleothems/dripstone hanging from a cave roof?
The cave roof was above the water table when the speleothems formed
How does the number of tributaries change for a stream that has had part of its flow captured (A in the example) and a stream that has pirated another stream (B in the example)?
The number of tributaries for the captured stream (A) decreases and the number of tributaries for the pirating stream (B) increases.
What is a stream terrace?
a remnant of an older floodplain that sits above the stream valley
Double-click the Drainage Pattern E placemark. Use the visibility slider to adjust the transparency of the map overlay from opaque to transparent and back so that you can view the terrain as well as the stream channels. Which type of drainage pattern is this?
annular drainage
Which common, rock-forming mineral or mineral group is most readily dissolved by groundwater?
calcite
Double-click the Drainage Pattern D placemark. Which type of drainage pattern is this?
deranged drainage
The unsaturated zone ________
lies above the water table
Which of the following geologic materials would have the highest groundwater velocities and be least effective in removing unwanted pollutants from the water?
limestone; numerous solution channels and fractures widened by dissolution
Where is erosion concentrated along a meandering stream?
on the outer parts of the meander loops or bends
Consider a steep highway cut made by removing slightly weathered to fresh, fractured, granite bedrock. Which of the following situations is most stable against rockslides?
one set of widely spaced, sub-horizontal fractures
Double-click the Drainage Pattern B placemark. Which type of drainage pattern is this?
parallel drainage
What force pushes groundwater from pore to pore below the water table?
pressure gradient or hydraulic gradient
Double-click the Drainage Pattern A placemark. Which type of drainage pattern is this?
radial drainage
Double-click the Drainage Pattern G placemark. Which type of drainage pattern is this?
rectangular drainage
Which of the following must result in a lower base level for rivers and streams?
sea level falls; land rises
A stream is said to be a losing stream when
the channel bottom is above the local water table
Imagine a valley containing four stream terraces. Where would the youngest stream terrace be found?
the lowest terrace
Double-click the Drainage Pattern C placemark. Which type of drainage pattern is this?
trellis drainage
An artesian well is one in which ________
water rises above the top of the aquifer without any pumping
When do streams erode laterally?
when downcutting is occurring in easy-to-erode sediment or rock
When do stream terraces form?
when streams exist under alternating erosional and depositional conditions
Using the example below, determine how flow will change as a result of stream piracy. The arrows indicate the original flow directions and the dotted line indicate where headward erosion has occurred.
Water would now flow from point A to point C.
