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Geology. APES. Geologic origin of rocks. Dynamic process…always changing. Geologic origin of rocks in Reference to SC Geologic Time sloooow process. Geologic Processes. Internal Processes Originating from Earth’s interior - PowerPoint PPT Presentation
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Geology
APES
Geologic origin of
rocks
Dynamic process…always changing
Geologic origin of rocks in
Reference to SC
Geologic Time
sloooow process
Geologic Processes Internal Processes
Originating from Earth’s interior Internal Processes drive plate tectonics, earthquakes, volcanoes
Plate Boundaries
Geologic processes (cont.) External Processes
Based on the energy from the sun and/or gravity Erosion and Weathering Erosion: material removed from one location and deposited
somewhere else. Weathering: produces the material to be eroded
Chemical Weathering
Limestone Statute, Bath, England
Limestone Cavern, KY
Lichens, Big Bend NP, TX
Physical Weathering
Columnar joints in the Tertiary intrusive Devils Tower at Devils Tower National Monument, WY. Note the talus derived from mechanical weathering of the columnar joints.
Weathering and Surface Area
Rocks vs. Minerals
Multiple rock types
Igneous, metamorphic or sedimentary
Low economic value
Uniform Igneous,
metamorphic, or sedimentary
Have significant value
Industrial Minerals in SC
Gold Mining in South Carolina
Haile Gold Mine, Kershaw Co.2.7 million ounces still there
Rock Types Sedimentary: formed
from sediments from pre-existing rocks
Igneous: pre-existing rocks melt below surface and are cooled
Metamorphic: pre-existing rocks are subjected to extreme pressure/temperature
Identifying Metamorphic Rocks
Type of parent material Color and thickness of
layers Angle of layers Evidence of folds and
faults Embedded material Type and impact of
weathering
Soil Mapping and Land Suitability
Potential future uses and therefore value
Building constraints (foundation stability, drainage)
Potential for erosion Types of crops Silviculture Regulatory constraints
(wetlands, steep slopes, groundwater recharge)
What is Soil?
Parent material is slate based metamorphic rock strongly influenced by millions of years of erosion
Typical soil is 45% geologic materials 25% water 25% air 5% organic matter
Soils at DFHS have high clay content, are blocky, and are friable (easily crumbled)
Typical Soil Profile
Soils Differ
Content: combination of sizes Clay – very fine particulate (sticky) Silt – fine particulate (smooth) Sand – medium sized particulate (gritty) Gravel – course particulate
This determines the soil texture Soils with equal mixtures are called loams
(best for plant)
Growth Suitability
Soil Permeability: determined by the spaces between the sediments. Measures the rate at which air/water can move through soil layers. Porosity – average distances. More porous can
hold more air/water Want to hold plenty of water, but not be too hard
where water cannot move through layers Soil Alkilnity: pH. Influences ability of plants to
get nutrients from the soil. Too alkaline or too acidic will not support plant
growth.
Soil Profile
5 major biomes related to soil profiles
Why Map Soils? Determine uses of land
and therefore its $$$ Locate building sites,
sewers, and septic tanks
Determine type of crops, grasses, and trees that can be planted
Comply with regulations protecting wetlands, steep slopes, and groundwater recharge areas
DFHS/DFMS Soil TypesSymbol Name Description
NaC Nason Deep, well drained, moderate to steep NaE Silt slopes, good for cotton, some limits NaB Loam on foundations due to clay and slopes
GeB Georgeville Moderately permeable, formed by GeC residual slate deposits, B horizon
more red than Nason soils, good for corn, soybeans, building foundations
USDA Soil Map of DFMS and DFHS Area
Old Tamah Road
DFMS
DFHS
Degradation of Soils How are soils degraded?
Over use: Farming Logging Grazing
Impacts? Loss of arable land
Erosion Desertification
What can be done?