X1016061229-00281-56729</DOCNO> Soils Soils Subtopics Making soil Weathering Erosion Soil-forming processes Soil profiles Soil classification and soil maps Soil problems Soil erosion Soil salinization Soil pollution Soil mining Soil problems as creeping environmental problems Coping with soil problems Making soil Weathering decomposition of rocks and minerals at surface may be chemical or mechanical Chemical weathering requires water especially water that is slightly acidic due to contact with atmospheric CO 2 works best with warmer temperatures feldspars become clays limestone dissolves quartz is unaffected dissolved constituents end up in water: Na+, Ca++, Mg++, (HCO3)- plants may secrete chemicals that enhance chemical weathering Mechanical weathering (= physical weathering) fractures frost fire salt crystallization plant roots and burrowing animals Chemical and mechanical weathering work together mechanical weathering provides pathways for water, enhancing chemical weathering chemical weathering weakens the rock, enhancing mechanical weathering Weathering is a function of: climate (14.7) rock type / structure topography hydrology vegetation time / geologic history Erosion the transport of material at the earth's surface Agents of erosion gravity (mass-wasting) water (streams and oceans) suspended material dissolved material ice (glaciers) wind Erosion is a natural process but erosion of soil can be greatly accelerated by human activities (see below) Weathering and erosion work together, but they are two completely different concepts: weathering = decomposition erosion = transport Soil-forming processes An amazing set of astro-geo-bio-atmo-hydro-logical processes create the world's second-most valuable substance----DIRT Soil is a complex function of: climate topography hydrology parent rock vegetation and soil biota (esp.
(Soils Soils Subtopics; Making; ) Context(Soils Soils Subtopics Making,List([32, 60))):(soil; Weathering; Erosion Soil-forming processes Soil profiles Soil classification and soil maps Soil problems Soil erosion Soil salinization Soil pollution Soil mining Soil problems) Context(Soils Soils Subtopics Making,List([32, 60))):(Soil problems Soil erosion Soil salinization Soil pollution Soil mining Soil problems as creeping environmental problems; may be; with warmer temperatures) Context(Soils Soils Subtopics Making Soil problems Soil erosion Soil salinization Soil pollution Soil mining Soil problems as creeping environmental problems may be,List([32, 379))):(chemical or mechanical Chemical weathering; requires; water especially water that is slightly acidic due to contact with atmospheric CO 2) (suspended material; dissolved; ) (they; are; two completely different concepts: weathering = decomposition erosion = transport Soil-forming processes) (chemicals; enhance; chemical weathering Mechanical weathering) Context(chemicals enhance,List([700, 722))):(chemical; weathering; Mechanical weathering) (water; is; slightly acidic) (DIRT Soil; is; a complex function of: climate topography hydrology parent rock vegetation and soil biota (esp) Context(DIRT Soil is,List([1748, 1760))):(suspended material dissolved material ice (glaciers) wind Erosion; is; a natural process) Context(suspended material dissolved material ice ( glaciers ) wind Erosion is DIRT Soil is,List([1312, 1760))):(chemical weathering chemical weathering; weakens; the rock) Context(chemical weathering chemical weathering weakens suspended material dissolved material ice ( glaciers ) wind Erosion is DIRT Soil is,List([975, 1760))):(chemical; weathering; chemical weathering) Context(chemical weathering chemical weathering weakens suspended material dissolved material ice ( glaciers ) wind Erosion is DIRT Soil is,List([975, 1760))):(Na+, Ca++, Mg++; fractures; frost fire salt crystallization plant roots and burrowing animals) Context(chemical weathering chemical weathering weakens suspended material dissolved material ice ( glaciers ) wind Erosion is DIRT Soil is,List([975, 1760))):(plants; may secrete; chemicals that enhance chemical weathering Mechanical weathering (= physical weathering)) Context(chemical weathering chemical weathering weakens suspended material dissolved material ice ( glaciers ) wind Erosion is DIRT Soil is,List([975, 1760))):(Chemical and mechanical weathering work together mechanical weathering; provides; pathways) Context(suspended material dissolved material ice ( glaciers ) wind Erosion is DIRT Soil is,List([1312, 1760))):(enhancing mechanical weathering Weathering; is; a function of: climate (14.7) rock type / structure topography hydrology vegetation time / geologic history Erosion the transport of material at the earth's surface Agents of erosion gravity (mass-wasting) water (streams and oceans) (erosion of soil; can be accelerated; by human activities) (An amazing set of astro-geo-bio-atmo-hydro-logical processes; create; the world's second-most valuable substance) (soil problems; Making; soil Weathering decomposition of rocks and minerals at surface)
Soils Soils Subtopics Making,List([32, 60)) Soils Soils Subtopics Making,List([32, 60)) Soils Soils Subtopics Making Soil problems Soil erosion Soil salinization Soil pollution Soil mining Soil problems as creeping environmental problems may be,List([32, 379)) chemicals enhance,List([700, 722)) DIRT Soil is,List([1748, 1760)) suspended material dissolved material ice ( glaciers ) wind Erosion is DIRT Soil is,List([1312, 1760)) chemical weathering chemical weathering weakens suspended material dissolved material ice ( glaciers ) wind Erosion is DIRT Soil is,List([975, 1760)) chemical weathering chemical weathering weakens suspended material dissolved material ice ( glaciers ) wind Erosion is DIRT Soil is,List([975, 1760)) chemical weathering chemical weathering weakens suspended material dissolved material ice ( glaciers ) wind Erosion is DIRT Soil is,List([975, 1760)) chemical weathering chemical weathering weakens suspended material dissolved material ice ( glaciers ) wind Erosion is DIRT Soil is,List([975, 1760)) suspended material dissolved material ice ( glaciers ) wind Erosion is DIRT Soil is,List([1312, 1760))
Soils Soils Subtopics soil Soil problems Soil erosion Soil salinization Soil pollution Soil mining Soil problems as creeping environmental problems chemical or mechanical Chemical weathering suspended material they chemicals chemical water DIRT Soil suspended material dissolved material ice (glaciers) wind Erosion chemical weathering chemical weathering chemical Na+, Ca++, Mg++ plants Chemical and mechanical weathering work together mechanical weathering enhancing mechanical weathering Weathering erosion of soil An amazing set of astro-geo-bio-atmo-hydro-logical processes soil problems
Making Weathering may be requires dissolved are enhance weathering is is is weakens weathering fractures may secrete provides is can be accelerated create Making
Erosion Soil-forming processes Soil profiles Soil classification and soil maps Soil problems Soil erosion Soil salinization Soil pollution Soil mining Soil problems
with warmer temperatures
water especially water that is slightly acidic due to contact with atmospheric CO 2
two completely different concepts: weathering = decomposition erosion = transport Soil-forming processes
chemical weathering Mechanical weathering
Mechanical weathering
slightly acidic
a complex function of: climate topography hydrology parent rock vegetation and soil biota (esp
a natural process
the rock
chemical weathering
frost fire salt crystallization plant roots and burrowing animals
chemicals that enhance chemical weathering Mechanical weathering (= physical weathering)
pathways
a function of: climate (14.7) rock type / structure topography hydrology vegetation time / geologic history Erosion the transport of material at the earth's surface Agents of erosion gravity (mass-wasting) water (streams and oceans
by human activities
the world's second-most valuable substance
soil Weathering decomposition of rocks and minerals at surface