Georgia Geology Flashcards
What is soil comprised of?
weathered minerals, organic matter, air, and water
Ideally, what additional elements are in soil?
Microflora and microfauna (fungi, bacteria, and small animals)
What soil has the finest sized particles?
Clay (<0.002 mm)
What soil has the second smallest size particles?
Silt (0.002 mm - 0.05 mm)
Silt transported by water creates what type of soil?
Alluvial soil
Silt transported by wind creates what type of soil?
Loess soil
What soil contains the largest particle size?
Sand (0.05 mm -2 mm)
define ‘fines’
soil particles smaller than sand, these could include both silt and clay
What size range is gravel?
2 mm - 3 inches (larger pieces are either cobble or boulders)
What range is a neutral pH?
6.6-7.3
What pH is an acidic soil? (acid)
below 6.5
What pH is an alkaline soil?
above 7.4
At what pH (both acidic and alkaline) will few plants survive?
less than 4.0 (acidic) and more than 8.5 (alkaline)
How do you raise low acidic soil pH levels?
add lime
How do you lower high alkaline soil pH levels?
add sulfur or sulfuric acid
soil association vs soil series
soil association is a landscape that has a distinctive proportional pattern of soils, consist of one or more major soils and at least one minor soil. Soil series are groups of soil that have profiles that are almost alike, differing in surface layer texture or underlying material; named for town or geographic feature near first soil observation.
What is a geologic map?
map that indicates the rock types underlying an area
How are geologic areas described and analyzed on a geologic map?
geologic areas are often described and analyzed in terms of the extent of soil cover overlying the rock and general physical properties of the soil cover and rock.
What is a physiographic section?
these sections represent the major geological regions of the state.
Erosion definition
process by which soil and rock are worn away by the action of wind, water, ice, or gravity
What is the most damaging action that causes erosion?
water
What soils are the most erodible? The least?
fine sand and silt are the most erodible, clay soils are least erodible
How does vegetation aid in E&S control?
vegetation can absorb energy of rain drops, bind soil particles, slow velocity of runoff water, increase the ability of soil to absorb, remove subsurface water between rainfalls.
What rock materials are clay evolved from?
feldspar and mica
What rock minerals so silt come from?
silica or feldspar
What mineral is sand comprised of?
any mineral, but mostly quartz
what are the US Dept of Agriculture 6 soil types?
Sand, Sandy Loam, Loam, Silt Loam, Clay Loam, Clay
