Name______Test Date______Period______

Weathering, Erosion, and Soil Study Guide

Word Bank – Use each word once.

Abrasionangle of reposebreakingcoldcontinentaldeflationdeposition

differentdryduneserosionfasterfertileflatfossil fuels

glaciergravityhorizonshumusinfiltratesironleachinglitterloess

mass movementmoremorenutrientsoxygenparent rock

partially-weatheredpowerfulsaltationsandbarssidesslopesslowlyslowly

smallersubsoilsurfacetopsoilvalleyvolumewaterwaterwater

warmweakwetwindwind

  1. The texture of soil which would provide the most nutrients for plants would have a lot of ______or decomposed organic material, not many large rocks, is not too close to the bedrock, and will hold the right amount of water.
  2. Mechanical weathering caused by the repeated freezing and thawing of ______breaks down rocks and forms soil.
  3. Acid precipitation, plant acids, and oxidation are all examples of chemical weathering. Acid precipitation is created when ______are burned. Some plants create acids as they grow that dissolve the rocks they live on. Oxidation is a chemical reaction that happens when ______combines with ______and water.
  4. Soil is made of sand, silt, clay, humus, air, and water. Soil develops in layers called ______.

O – This horizon is covered with twigs, leaves, and bark called______. Organic material from dead plants and animals is also present. As this organic material decomposes, it turns into humus.

A – This is the ______. It is a dark color.

E – Intense ______happens here. Minerals dissolve out of the soil as water ______downward.

B – This is the ______. The dissolved minerals and nutrients from above collect here.

C – This is the ______bedrock.

R – Unweathered bedrock (also known as ______)

  1. Larger rocks weather ______because they have less surface area compared to their ______. ______pieces of rock weather ______because they have ______surface area compared to their volume.
  2. Remember differential weathering? Some rock material is harder than others and is more resistant to weathering. While the harder rocks weather ______, the softer surrounding rocks wear away, leaving the hard rock exposed at the ______.
  3. Abrasion happens when ______or ______moves sand and silt against exposed rocks which causes them to wear away. The longer a rock is exposed to ______, the more smooth and rounded it will become.
  4. Chemical weathering happens faster in regions that have a ______and ______climate. It happens more slowly where the climate is ______and ______.
  5. Contour plowing is when farmers plant rows of crops along the ______of hills to prevent erosion and conserve soil. Terracing is when farmers dig ______surfaces into the ______of steep hills or mountains. Crop rotation is a soil conservation strategy where farmers plant ______crops each year so they use fewer or different ______from the soil. Some crops even put nutrients back into the soil.
  6. ______soil has the ability to hold lots of nutrients for plants to use.
  7. Weathering is the ______down of rock material into smaller pieces. Erosion happens next when ______, ______, or ______move the small pieces to a different place. When the pieces get to a calm place, they drop out of the wind, water or gravity that has carried it, and that is called ______. ______are created when deposition happens in areas like the river deltas or inside the bend of a river.
  8. Water is ______dense than wind, so it is a more ______agent of erosion, and it works faster in shaping the Earth’s surface. Wind is a very ______agent of ______, so change in the Earth’s surface happens slowly over a very long time. ______happens when wind removes fine sediment. When the small particles bounce and skip in the direction of the blowing wind that is called ______. When sand is deposited, ______form. They are mounds of sand that constantly shift as the wind continues to blow. ______is a special kind of fine-grained glacial sediment that has been deposited by wind.
  9. Gravity also causes erosion. The ______is the steepest angle rock material can hold on without sliding downhill. When the angle is too steep, ______happens. Landslides, mudflows, slumps, and creeps are all examples of mass movement. Mass movement of ice is called a ______. ______glaciers cover a very large area with very thick ice. They create a flattened landscape with small, round lakes called kettles. ______glaciers build up in mountainous areas and carve out U-shaped valleys that rivers run through.