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50 Cards in this Set
- Front
- Back
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What is weathering?
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Weathering is the physical, chemical, and/or biologicla processes that alter rocks and minerals at the Earth's surface
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What are the 3 types of weathering?
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1. physical(AKA mechanical): when rock is broken apart
2. biological: breaking rock by something living 3. chemical: disintigration of a rock |
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Types of physical weathering
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1. Pressure release(AKA unloading)
2. Abrasion 3. freeze thaw 4. Thermal expansion 5. Salt wedging 6.hydraulic weathering or hydraulic action |
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What is pressure release?
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overlaying pressure is reduced in a rock. Causes a fracture called joints
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What is an abrasion
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the removal of rock material by grinding. Often the result of one rock against another.
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What is a joint?
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parallel sets of fractures that further exposes crust to weathering. Horizontal fractures are called sheeted joints. Formed by tectonic uplift or erosion of the overlying rock or unloading of a glacier
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Types of abrasion
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Glacial abrasion - rocks in a glacier cuts grooves in the underlying grooves
sand blasting- flying sand hits rock hard |
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what is salt wedging?
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The growth of salt by evaporation of water. ions come together to form minerals. Growth of minerals breaks rocks.
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What is hydrolysis
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ions in mineral react with H+ and OH in water and acid helps this reaction to proceed.
Caves are formed this way |
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What 4 factors influence wathering?
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1 time
2rock type(minerals): minerals and how stable they are 3 rock texture: large or small grains 4 climate: precipitation, wather, environemtal factors |
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What are the major determinants on the rate of weathering?
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Climate and type of minerals are the primary factors that determine the rate of weathering.
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What minerals are less stable?
What minerals are mors stable? |
Minerals formed at high pressure and temperature are less stable at the surface.
Minerals formed deep in the earth are stable. Colent boned minerals form closer to the Earth's surfacce and are more stable |
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Describe a climate where temp and rainfall are high
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(tropics) chemical weathering is most important. Lots of calcite, iron and soil development.
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Describe a climate where temp is high but rain is low.
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(desert) low soil development and vegetation and water for chemical weathering to occur. weathering usuallt from wind or evaporation.
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what 4 ways does weathering affect the earth?
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1. soil - increased clay and organic material help cultivation
2. soluble salts - soluble ions of minerals (Na, Cl, Ca) are found in water and affect water usability 3. weakened materials - chemical reactions break down rocks 4. material for erosion |
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What is the lithification process?
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compaction, dewatering, cementation
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cross bedding
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where sediment accumulates on a steep slope of a ripple or sand dune or front of a delta so the beds form at an angle
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well-sorted is?
poorly sorted is? |
grains are of similar size
wide variety of grain size |
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What is a bioclastic sedimentary rock
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contains fossils(shell) fragments
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What is an A horizon?
Compare and contrast |
(semi-arid): contains organic matter; depth of the root zone. top soil where plants grow organic matter.
(arid): contains organic matter and vesicles (air bubble holes) |
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What is a B horizon?
Compare and contrast |
clays, subsoil, low inorganic material
(semi-arid): contains clays that have been leached from above (arid): zone where carbonate is precipitating |
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What is C horizon?
Compare and contrast |
(arid & semi-arid): parent rock
transitional area between the soil and the bedrock/parent rock. remember that A and B horizons were once parent rocks. |
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What are soil horizons?
set of hoizons? |
layers of soil
soil profile |
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What is Paleosol?
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soil horizon that has become rock. It is very old. buried soil preserved by being buried uner sediments and then lithified.
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What do soils do?
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change the surface conditions and increas or decrease
1 infiltration of water 2 erosion 3 plant growth |
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3 types of sedimentary rocks
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clastic
chemical biogenic |
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What are clasts?
what are chemcial sedimentary rocks? |
particles of rock
inorganic precipitation of minerals |
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What is lithification?
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Buried sediments experince heat and pressure
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What is compaction?
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Compression of sediment during burial
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clastic sedimentary are classified by?
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clastic sedimentary are classified by:
1. size 2. sorting 3. roundness 4. minerology |
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Do metamorphic rocks melt?
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No
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What is a protolith?
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The parent rock
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The two types of metamorphosis are?
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regional and contact
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What is regional metamorphism?
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metamorphism over large areas, high- low pressure and temperature
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Contact metamorphism is?
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metamorphism near an igneous intrusion; high temperature, low pressure
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What is foliation?
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Showing a distinct banding of different colored minerals or orientation of sheets
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What is oxidation?
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The loss of electron from the positively charged ion(cation) that allows cation to bond with oxygen to form a new mineral
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___________ metamorphic rocks form at temperatures above 200 degrees C.
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Both contact and regional rocks form a temperatures above 200 degrees Celsius
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___________ metamorphic rocks include granites.
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Neither contact or regional
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Metamorphism of limestone forms ____________
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Marble
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Metamorphism of sandstone forms ____________
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Quartzites
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____________ may form from a sedimentary rock.
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Both contact and regional metamorphism
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__________ is the planer alignment of minerals (like biotite) due to differential stress during metamorphism.
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Foliation
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Metamorphism may involve two main processes: __________________.
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mechanical deformation and chemical recrystallization
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____________ metamorphic rocks are found surrounding magma or lava.
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Contact
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Where two converging plate meet, like the Himalayas, you would expect to find _________ metamorphic rocks.
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regional
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Chemical weathering is?
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A reaction where the composition of the mineral is changed. Usually takes place in water.
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What is oxidation?
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Rust forming
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What is erosion?
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The transport of weathered material
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What is the finest grade of metamorphic rock?
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gneiss
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