Weathering Hydrology NOTES PAGE 6 ©Mark Place, 2009-2010 www.LearnEarthScience.com

Weathering Physical ( Mechanical ) Abrasion Frost Action/ Frost Wedging Biologic Activity Exfoliation

Chemical Weathering occurs fastest in this type of environment: oxidation hydration Chemical Chemical Weathering occurs fastest in this type of environment: warm, moist

Plant Acids- Lichens produce weak acids that can dissolve certain minerals in a rock, weakening the rock.

Pebbles Sand Silt Clay Which will weather faster and why? Surface Area and Weathering Which will weather faster and why? Pebbles Sand Silt Clay Why will smaller particles weather faster? smaller particles have larger surface areas because it is the smallest

Soil 1. Soil is a combination of _____________ and _________________. 2. ____________ = decayed plant and animal material found in soil. Soil that contains 20-30% humus is considered a rich soil for plant growth. Weathered rock Organic matter Humus 3. Soil development

4. Soil layers- the soil profile Topsoil A Horizon ___________ or ___________ = the top layer of soil that contains more humus than the layers below. Sub soil B Horizon ___________ or ___________ = consists of clays and dissolved minerals that have been washed down from above. Contains less humus. C Horizon ___________ = consists of weathered rock fragments, usually from the parent rock below. Bedrock ___________ = the layer of rock beneath the soil. Frequently the parent rock of the soil above.

5. Residual Vs. Transported If the bedrock matches the rock fragments of the C horizon, the soil is most likely _________________. If it does not, the soil is most likely ____________________. Residual Soil Transported Soil NYS mostly has Transported Soil from continental glaciers moving soil from the north.

REGENTS REVIEW In which type of climate does chemical weathering usually occur most rapidly? 1. hot and dry 2. hot and wet 3. cold and dry 4. cold and wet 2

4 2.Which change in the climate of a location would most likely cause the greatest increase in chemical weathering of local bedrock? 1.lower temperature in winter 2.lower humidity in winter 3.higher atmospheric pressure in summer 4.greater precipitation in summer

3.Which type of climate has the greatest amount of rock weathering caused by frost action? a dry climate in which temperatures remain below freezing a dry climate in which temperatures alternate between below freezing to above freezing a wet climate in which temperatures remain below freezing a wet climate in which temperatures alternate between below freezing to above freezing 4

4. The diagram shows a process called frost wedging 4. The diagram shows a process called frost wedging.  Frost wedging is an example of weathering cementing metamorphism deposition 1

5. Landscapes will undergo the most chemical weathering if the climate is 1.cool and dry 2.cool and wet 3.warm and dry 4.warm and wet 4

6. Which activity demonstrates chemical weathering? 1.freezing of water in the cracks of a sandstone sidewalk 2.abrasion of a streambed by tumbling rocks 3.grinding of talc into a powder 4.dissolving of limestone by acid rain 4

4 7. Which process is best illustrated by the diagram? cementation erosion metamorphism weathering 4

8. As a result of the changes in temperature and amount of carbon dioxide, what probably happened to Earth's overall rate of chemical weathering during this time? 1.The rate of chemical weathering decreased. 2. The rate of chemical weathering increases. 3. The rate of chemical weathering remained the same 2

1 9. The diagram shows granite bedrock with cracks. Water has seeped into the cracks and frozen. The arrows represent the directions in which the cracks have widened due to weathering. Which statement best describes the physical weathering shown by the diagram? Enlargement of the cracks occurs because water expands when it freezes. This type of weathering occurs only in bedrock composed of granite. The cracks become wider because of chemical reactions between water and the rock. This type of weathering is common in regions of primarily warm and humid climates.

Where is the rock more resistant to weathering? F A C E B D

Where is the rock least resistant to weathering? F A C E B D

You might also see it like this…

You might also see it like this…