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?