Definitions
the mechanical weathering process in which water in the cracks of rocks freezes and expands, widening the cracks
ice wedging
Gullies are created when the wind deposits particles picked up during deflation.
False. Dunes are created when the wind deposits particles picked up during deflation.
The type of rock most easily weathered is
a sedimentary.
b igneous.
c metamorphic.
d quartz.
A
Explain two ways continental glacial erosion may have formed kettle lakes.
Continental glacier erosion could have scooped out the lake beds for kettle lakes. They also could have formed when sediment covered a block of ice that was separated from a retreating glacier. When the sediment fell in on itself as the ice melted, it would have created a water-filled pit
the wearing down of rock surfaces by other rocks or sand particles
Abrasion
Shoreline erosion increases during summer months.
False. Shoreline erosion increases during winter months.
Where might water slow down enough to deposit its load?
a along the inside curve of a bend
b on a floodplain
c at a river’s mouth
d all of the above
d
Describe how the rate of mechanical weathering can be increased.
The following increase the rate of mechanical weathering:
temperature extremes;
activities of living things (tree roots infiltrating rock crevices);
climate factors, including ice wedging, frequent precipitation, and rapid temperature increases; t
he amount of exposed surface area;
high elevation; and gravity.
Imagine life without soil. If such conditions existed, what would life be like?
Answers will vary but should include that soil is the foundation of physical life on Earth. The primary role of soil is to provide an environment and resources that foster the health and growth of the plant kingdom, bacteria, protists, and other small organisms. If a variety of ecosystems was disrupted by a lack of soil, catastrophic effects would be witnessed. Life on Earth would not exist. The food chain would completely unravel and the supply of oxygen needed to sustain life would be severely depleted. The planet would be subject to more prevalent drought and flooding and would not be able to adapt to climate changes.
the breaking down of rocks by chemical processes
the breaking down of rocks by physical processes
chemical weathering
mechanical weathering
Clay particles are smaller than silt particles.
true
Landslides, mudflows, and soil creep are all similar in that
a they all involve soil moving downhill.
b they require freezing and thawing of
ice to occur.
c they are all triggered by earthquakes
and volcanoes.
d they require steep slopes to occur.
a
Describe two types of unconformities.
disconformities: occur when a there is an eroded portion of rock between two horizontal sedimentary layers;
nonconformities: occur when there is an eroded portion of rock between a sedimentary layer and a layer of igneous or metamorphic rock;
angular unconformities: occur when the horizontal layers of rock that are brought to the surface tilt or fold, are exposed to the effects of erosion, and are covered by a new horizontal layer of sedimentary rock
the eroded surface that lies between two groups of strata
a narrow ditch cut in the earth by runoff
Unconformity
gully
Climate, a major factor of mechanical weathering, helps determine the type of soil created.
true
Most fossils are found in rock.
a igneous
b sedimentary
c felsic
d metamorphic
b
Explain why river bends are affected by both erosion and sediment deposition.
Water flows slowly along the inside of the bends, depositing sediment, but water flows quickly along curves’ outer edges, which causes erosion.
It has been Angelica’s dream to build a secluded beach resort. However, past entrepreneurs have built resorts in similar locations only to be out of business in a few years because of erosion. The beach has been restored and Angelica would like for her beach resort to serve guests for many years to come. What environmental factors must she consider when developing a plan to build her beach resort? What steps should she take to prevent her resort from being washed out to sea?
Answers will vary but should include the following: the force and frequency of ocean waves; the mechanical and chemical weathering; the climate, including the amount of precipitation and temperature extremes; the amount and strength of wind gusts; the biological factors; the possibility of mass wasting. Possible solutions to the erosion problem are to build a wall to deflect waves and currents or encourage sand deposits, to bring in sand from nearby locations, or to encourage the formation of beach dunes by building fences or planting vegetation to hold the sand in place.
a fossil that is useful for dating and correlating the strata in which it is found
a process in which the organic portion of an organism is infiltrated or replaced with minerals
a fossil of a track, trail, or burrow
index fossil
Petrification
trace fossil
Old-earth scientists theorize that lower layers of strata found in a geologic column are younger than strata layers found closer to the surface according to the law of superposition.
False. Old-earth scientists assume that lower strata layers found in a geologic column are older than strata layers found closer to the surface according to the law of superposition.
What three factors other than climate and slope of land help determine the type of soil in a region?
type of vegetation, parent rock material, and time
Describe in detail two types of mass wasting.
Landslides are the rapid downhill movement of a large amount of rock and soil along a distinct plane. They occur when topsoil and rock overcome the gravitational forces that hold them to a lower layer. If landslides occur as large blocks of soil and rock that slide down a concave slope, they are called slumps. Rock slides are landslides that primarily involve rocks. These usually start on steep slopes when huge chunks of rock come loose from the bedrock and slide downhill.
Mudflows are the rapid downhill movement of large masses of mud and debris. They occur when a large amount of water mixes with soil and rock. Mudflows are different from landslides because of their high water content, which causes them to behave more like rivers.