Download Geology and Soil Formation: Definitions and Processes and more Quizzes Geology in PDF only on Docsity! TERM 1 Geologist definition of soil DEFINITION 1 -weathered rock / sediment TERM 2 Geologist definition of parent material DEFINITION 2 -unweathered rock / sediment TERM 3 Creation of soil DEFINITION 3 -Rock weathered into dissolved ions, clay minerals, quartz, Fe and Al oxides-Become mature soil and hard water thru leaching TERM 4 Leaching DEFINITION 4 -percolating water dissolving and removing material-changes soil chemistry-changes water chemistry TERM 5 zone of leaching DEFINITION 5 -sequence (from most to least likely present):1. soluble minerals (salts, calcite)2. organic matter3.Fe, Al oxides (carried by dissolved organics)4. clays (carried in suspension)5. quartz (extremely low solubility) TERM 6 zone of accumulation DEFINITION 6 -sequence (most likely to least likely present):1. Fe, Al oxides (organics that carried them decompose)2. clays (if water slows down)3. dissolved minerals (only if water evaporates; only occurs in desert conditions) TERM 7 Destruction of soil DEFINITION 7 -Thru removal by erosion and burial by sedimentation TERM 8 Soil Layer A DEFINITION 8 -zone of leaching-organic materials present-low solubility minerals present (quartz, some clay)-organics cause black color of upper layer-sometimes white below TERM 9 Soil Layer B DEFINITION 9 -zone of accumulation-Fe, Al oxides-clay usually present- some soluble minerals present-rust colored (due to Fe)- sometimes white colored (due to calcite) TERM 10 Soil Layer C DEFINITION 10 -partly weathered parent material-little leaching or accumulation TERM 21 Ultisols DEFINITION 21 -red clay soils**Most common in VA**-strongly leached-poor fertility (need lime, fertilizer)-no Ca ; acidic-Fe, Al in B layer; gives red color-clay accumulation in B layer-found in wet climates, forest envinronments-take 100k's years to mature TERM 22 Alfisols DEFINITION 22 -moderately leached-some Ca; mildly acidic-some Al, Fe oxides-some clay accumulation in B layer-fertile-found in moist climate, forest environments TERM 23 Inceptisols DEFINITION 23 -weakly leached-no clay or oxide accumulation in B layer-just starting to leach soils-weakly developed horizons-found in moist climate TERM 24 Entisols DEFINITION 24 -undeveloped soil-no leaching; only A horizon-rapid sedimentation TERM 25 Histosols DEFINITION 25 -peat / muck-organic-dominated soils-coal-forming envionments-found in bogs, swamps TERM 26 Clay minerals DEFINITION 26 -sheet silicates-microscopic, flat crystals-created by weathering-electrically negative mineral surface; attaches with cations and water TERM 27 Clay strength DEFINITION 27 -flocculated:The process by which individual particles of clay aggregate into clotlike masses or precipitate into small lumps-attached by Ca and Mg ions-mechanically weak- permeable-adding layers => cations leach out => particles dispersed-dispersed particles very weak, very low permeability TERM 28 Clay permeability DEFINITION 28 -very low permeability-used as groundwater flow barrier; separated aquifers, prevents flow of contaminated water- petroleum flow barrier; traps petroleum, shale acts as cap rock (impermeable layer) TERM 29 Clay and water DEFINITION 29 -clay mineral surface negatively charged; grabs water-high compressibility; slowly squeezes when load applied- expansive soil; expands when wet, contracts when dry TERM 30 Clay and soil fertility DEFINITION 30 -Negative surface charge grabs cations-slows leaching of elements; essential for fertility
