Lecture 5b, 6, & 7a: Soils I, II, & III Spring 2007 WVU GEOL 321 (J.S. Kite) Soil: Assemblage of natural bodies on the Earth s surface (natural or artificial) capable of supporting plant life outdoors Pedon: Area on Earth s surface w/ single type of soil Also: soil mapping unit. NSF-REU program "A Field-Based Study of Landscape Evolution in Western Colorado." Mesa State College is recruiting undergraduate Geology students for 2007 summer Provide undergraduate students (sophomore or junior standing in Fall 2007 preferred; students who WILL NOT graduate by Spring 2008) with opportunity to gain research experience. 8 weeks (May 21-July 13) training, field work, & data compilation. Students will present results of their research at 2007 GSA meeting in Denver. No course prerequisites, but would like students to have completed at least Physical and Historical Geology. Each student will receive a stipend ($2400 for the 8 wk period), housing, a meal allowance (~$1,000), & round-trip travel to & from Grand Junction, CO. Also a $600 travel allowance to attend the GSA meeting in Denver, CO (Oct 28-31, 2007 ). 1
Soil Development Is a Function of 5 Factors S = ƒ (Cl,O,R,P,T) 1. Climate 2. Organisms 3. Relief 4. Parent material 5. Time Factors of Soil Development 1. Climate Temperature & Moisture Affect Eh & Redox Reactions Fe (Iron) Depletions Gray Reduced Iron (Water-Logged) Fe (Iron) Concentrations Red Mottles of Oxidized Iron (= Redoximorphic features) Factors of Soil Development 2. Organisms - Microorganisms (Bacteria, Fungi) Decompose organic material into humus Macroorganisms Bioturbation by Trees, Worms, Crayfish, Groundhogs, Gophers, Grizzly Bears Organisms Supply material Leaves (Conniferous vs. Deciduous Forests) Roots (Grasslands) 2
Factors of Soil Development 3. Relief Slope Steep Slopes: Well Drained, Erosion Low Slopes: Poorly Drained, Deposition Aspect Direction slope faces affects temperature & moisture Factors of Soil Development 4. Parent Material Material from which soil develops Types of Parent Material Residual Soil = Residuum Bedrock weathers in situ, on low relief & little erosion Parent Material, (cont.) Colluvial Transported by Gravity Alluvial Material Transported by Streams Glacial Transported by Glaciers Eolian Transported by Wind 3
Factors of Soil Development 5. Time Needed to Form Soils Depends on Other Factors Warm Climates Form Soil Faster Than Cold Biological & Geochemical Reactions Act 2X Faster for Every 10 o C Increase Water = a must in Pedochemical Reactions, Translocation Parent Material Affects Time to Form Soil Soil Properties Through Time Increasing Soil Development Geometric Logarithmic Steady State Increasing Time Soil Characteristics 1. Color Typically Formed by three substances 1. Humus Decomposed organic material 2. Iron (Fe) 3. Carbonate Munsell soil color chart 4
Soil Characteristics cont. 2. Texture (USDA) = size of soil particles in matrix Sand = 2.0 to 0.05 mm Silt = 0.05 to 0.002 mm Clay = less than 0.002 mm Excludes particles >2 mm Loam = Significant percentage of all three (2 sand: 2 silt: 1 clay) Soil Characteristics cont. Textural Triangle Texture determined by two methods 1. Particle Size Analysis Laboratory method 2. By Feel (Field method) Takes lots of practice High clay content will cause soil to form ribbon when rolled. Soil Texture Triangle 60 100 90 80 70 Clay 10 20 Percent Silt 30 40 10 20 Percent Clay 50 40 30 Loamy Sand Sand 90 80 Sandy Clay Sandy Clay Loam Sandy Loam 70 60 50 40 30 50 Silty Clay Silty Clay Clay Loam Loam Loam 60 Silt Loam 20 70 80 Silt 10 90 100 100 Percent Sand 5
Soil Characteristics cont. 3. Soil Structure PEDS: aggregates of particles Types of Structure Blocky (well developed) Platy Prismatic Columnar Granular (high organics) Soil Horizons Soil Profile Described from the surface down Solum True soil = A &/or E & B horizons Soil & Ground Water Distribution Eastern USA Soil Moisture Belt Unsaturated (= Vadose = Aeration) Zone Capillary Fringe Water Table Saturated (= Phreatic) Zone 6
Soil & Ground Water Distribution Western USA Soil Moisture Belt Phreatophytes Unsaturated (= Vadose = Aeration) Zone Capillary Fringe Water Table Saturated (Phreatic) Zone Soil Horizons Idealized Soil Profile Solum = A, E, and B { Surface L Horizon O Horizon A Horizon E Horizon B Horizon Leaf Litter Decomposed Organics Top Soil Leached Horizon Subsoil C Horizon Weathered (?) Parent Material R Horizon Bedrock Soil Horizons cont. L = New leaf litter In forest soils O = Organic Layer Partly decomposed organic matter A = Top Soil Mix of inorganic & organic material Eluvial horizon Most fertile soil horizon 7
E = Eluvial Horizon Soil Horizons cont. Organics & minerals even more elluviated, light color horizon B = Subsoil Illuvial horizon High clay content? Maximum soil development Soil Horizons (cont.) C = Weathered Parent Material or Unweathered Transported Material Has NOT undergone soil formation R = Bedrock Unweathered Bedrock EPIPEDONS Mollic: Diagnostic Horizons dark, > 1% O.M. in upper 7, >50% base saturation Ochric: light, < 1% O.M. Umbric: dark, <50% base saturation Histic: peaty surface layer Plaggen: >20 of manure applied over long time 8
Diagnostic Horizons cont. SUBSURFACE HORIZONS Spodic: buildup of humus Argillic: buildup of clay Cambic: incomplete argillic or spodic horizon Oxic: high clay, 1:1 clay, low CEC Petrocalcic: Concentration of carbonates Albic: light colored E horizon Other Common Soil Horizons Fragipan: brittle layer with high bulk density Saprolite: soil mineralogy w/ relict bedrock structure Fragipan:Top view of truncated soil - Canaan Valley Btx horizon J.S. Kite Photo Fragipan: Side view showing reduced tongues J.S. Kite Photo 9
Subdivisions of Horizons: A B 1 not written B2 B3 BC 2 BC Change in Parent Material 2 C 3 C Change in Parent Material lower case notations to horizons: Ap Bw C Ab Bt BC C p = disturbed (plowed?) A w = incipient (weak) B b = buried A t = argillic clay build-up Catena Sequence of soils of about the same age, derived from similar parent material, and occurring under similar climate conditions, but having different characteristics due to variation in relief and in drainage. SSSA Internet Glossary of Soil Science Terms http://www.soils.org/sssagloss/ 10
Catena, Alberta www.soils.rr.ualberta.ca/soa/catena3.cfm Fourth Annual Student Night joint meeting of the Association of Engineering Geologists, the Pittsburgh Geological Society, and the Geotechnical Group of the Pittsburgh Section of the American Society of Civil Engineers. CALL FOR ABSTRACTS! Students are invited to submit abstracts (no more than 350 words) of a Senior Research Project, Senior Design Project, Master s or PhD Thesis on the following topics : Geology, Engineering Geology, Geotechnical Engineering, Environmental Engineering, Hydrogeology, Hydrology Three students will be selected to give a 15-20 minute oral presentation based on their abstract submittal. Students not selected to give an oral presentation will be invited to present a poster summarizing their work. The students selected to give oral presentations will receive $100 awards. All students who present their research will receive a membership into PGS. Meeting Logistics April 18, 2007 6:00 p.m. Foster s Restaurant, Foster Plaza Bldg. 10, Green Tree, PA THE DUE DATE FOR ABSTRACT SUBMITTAL IS MARCH 9, 2007. Notification will be given to the selected speakers on March 16, 2007. Abstracts may be submitted via email to barnerwl@cdm.com. If you have any questions or require a mailing address for abstract submittal please call Wendell Barner at 412-208-2409. Soil and Soil Development Soil Handout 11
Soil Taxonomy 6 Levels of Classification Order Suborder Great Group Subgroup Family Series Soil Taxonomy Tucker County Mine Soil Loamy-skeletal, mixed, acid, frigid Typic Udorthent ent = Entisol (ent as in recent) [Soil Order] orth = Common (typical entisol) [Suborder] Ud = Humid climate [Great Group] Typic = Common (typical udorthent) [Subgroup] frigid = Cold climate acid = ph less than 4.0 mixed = mixed mineralogy of materials in the soil skeletal = greater than 35% rock fragments in soil Loamy = textural classification = LOAM ORDER FORMATIVE ELEMENT Entisol ent no horizons Inceptisol ept incipient horizons - Cambic horizon Alfisol alf argillic horizon, high B.S. >35% Ultisol ult argillic horizon, low B.S. <35% Oxisol ox oxic horizon Mollisol oll mollic epidedon Spodosol od spodic horizon Vertisol ert shrink-swell soils Aridisol id dry >50% of year Histosol ist >30% organic matter Andisols and tephras Gelisols el permafrost 12
Suborder Formative Elements Alb - White Albino Aqu - Wet Arg - Argillic Horizon Ferr - Iron etc. Examples of Suborders (2 Formative Elements): Albolls - Aquolls - Rendolls - Xerolls - Borolls - Albic Horizon Wet (Aqueous) Rendzina (Lots O. M. + Hi ph) Xeric Dry Season Boreal Cool Mon-Marion County Soil Survey See P. 157 13
West Virginia State Soil (1997) Monongahela Silt Loam feet Fine-loamy, mixed, semiactive, mesic Typic Fragiudults Source of image & text for 2 slides: www.statlab.iastate.edu/soils/ photogal/statesoils/wv_soil.htm Monongahela soils occur on >100,000 acres in 45 counties in West Virginia. These very deep, moderately welldrained soils are on alluvial or glaciallake terraces (after NRCS w/ JSK modif.) Generalized Distribution TYPE LOCATION: 2.7 mi E of Beverly, 100 ft N of church on N boundary of 4-H Camp, Randolph Co., WV; MLRA OFFICE: Morgantown, WV SERIES ESTABLISHED: Greene County, Pennsylvania, 1921. DIAGNOSTIC HORIZONS, etc. Ochric epipedon - 0 to 12 inches (Ap & BA horizons). Argillic horizon - 12 to 22 inches (Bt horizon). Fragipan - 22 to 52 inches (Btx horizon). Source of image and text for 3 slides: www.statlab.iastate.edu/soils/ osd/dat/m/monongahela.html 14
Ap--0 to 7 inches; dark grayish brown (10YR 4/2) silt loam; moderate fine granular structure; friable; many roots; slightly acid; abrupt smooth boundary. (6 to 10 inches thick) BA--7 to 12 inches; yellowish brown (10YR 5/4) silt loam; weak fine subangular blocky structure; friable; common roots; slightly acid; clear smooth boundary. (0 to 7 inches thick) Bt--12 to 22 inches; yellowish brown (10YR 5/6) silt loam; weak to moderate fine subangular blocky structure; friable; common roots; few distinct clay films on faces of peds; moderately acid; clear wavy boundary. (8 to 20 inches thick) Btx1--22 to 31 inches; yellowish brown (10YR 5/4) loam; common fine distinct yellowish brown (10YR 5/8) and light brownish gray (2.5Y 6/2) mottles; weak coarse prismatic structure parting to weak coarse platy; firm; few distinct clay films; very strongly acid; clear irregular boundary. (7 to 14 inches thick) Btx2--31 to 42 inches; light yellowish brown (10YR 6/4) loam; many medium distin\ct yellowish brown (10YR 5/8) and light brownish gray (2.5Y 6/2) mottles; weak very coarse prismatic structure parting to weak coarse platy; very firm, brittle; few distinct clay films; very strongly acid; clear wavy boundary. (8 to 15 inches thick) Btx3--42 to 52 inches; light yellowish brown (10YR 6/4) cobbly loam; many distinct yellowish brown (10YR 5/8) and light brownish gray (2.5Y 6/2) mottles; weak very coarse prismatic structure parting to weak coarse platy; very firm, brittle; few distinct clay films; numerous fine pores; 25 percent sandstones cobbles; very strongly acid; clear wavy boundary. (0 to 12 inches thick) C--52 to 65 inches; mixed strong brown (7.5YR 5/8) and light gray (N 7/ ) clay loam, pale yellow (2.5Y 7/4) crushed massive; firm; 35 percent weathered shale, sandstone fragments and cobbles; very strongly acid; clear smooth boundary. Ap--0 to 7 inches; dark grayish brown (10YR 4/2) silt loam; moderate fine granular structure; friable; many roots; slightly acid; abrupt smooth boundary. (6 to 10 inches thick) BA--7 to 12 inches; yellowish brown (10YR 5/4) silt loam; weak fine subangular blocky structure; friable; common roots; slightly acid; clear smooth boundary. (0 to 7 inches thick) Bt--12 to 22 inches; yellowish brown (10YR 5/6) silt loam; weak to moderate fine subangular blocky structure; friable; common roots; few distinct clay films on faces of peds; moderately acid; clear wavy boundary. (8 to 20 inches thick) Btx1--22 to 31 inches; yellowish brown (10YR 5/4) loam; common fine distinct yellowish brown (10YR 5/8) and light brownish gray (2.5Y 6/2) mottles; weak coarse prismatic structure parting to weak coarse platy; firm; few distinct clay films; very strongly acid; clear irregular boundary. (7 to 14 inches thick) Btx2--31 to 42 inches; light yellowish brown (10YR 6/4) loam; many medium distinct yellowish brown (10YR 5/8) and light brownish gray (2.5Y 6/2) mottles; weak very coarse prismatic structure parting to weak coarse platy; very firm, brittle; few distinct clay films; very strongly acid; clear wavy boundary. (8 to 15 inches thick) Btx3--42 to 52 inches; light yellowish brown (10YR 6/4) cobbly loam; many distinct yellowish brown (10YR 5/8) and light brownish gray (2.5Y 6/2) mottles; weak very coarse prismatic structure parting to weak coarse platy; very firm, brittle; few distinct clay films; numerous fine pores; 25 percent sandstones cobbles; very strongly acid; clear wavy boundary. (0 to 12 inches thick) C--52 to 65 inches; mixed strong brown (7.5YR 5/8) and light gray (N 7/ ) clay loam, pale yellow (2.5Y 7/4) crushed massive; firm; 35 percent weathered shale, sandstone fragments and cobbles; very strongly acid; clear smooth boundary. Ap--0 to 7 inches; dark grayish brown (10YR 4/2) silt loam; moderate fine granular structure; friable; many roots; slightly acid; abrupt smooth boundary. (6 to 10 inches thick) BA--7 to 12 inches; yellowish brown (10YR 5/4) silt loam; weak fine subangular blocky structure; friable; common roots; slightly acid; clear smooth boundary. (0 to 7 inches thick) Bt--12 to 22 inches; yellowish brown (10YR 5/6) silt loam; weak to moderate fine subangular blocky structure; friable; common roots; few distinct clay films on faces of peds; moderately acid; clear wavy boundary. (8 to 20 inches thick) Btx1--22 to 31 inches; yellowish brown (10YR 5/4) loam; common fine distinct yellowish brown (10YR 5/8) and light brownish gray (2.5Y 6/2) mottles; weak coarse prismatic structure parting to weak coarse platy; firm; few distinct clay films; very strongly acid; clear irregular boundary. (7 to 14 inches thick) Btx2--31 to 42 inches; light yellowish brown (10YR 6/4) loam; many medium distinct yellowish brown (10YR 5/8) and light brownish gray (2.5Y 6/2) mottles; weak very coarse prismatic structure parting to weak coarse platy; very firm, brittle; few distinct clay films; very strongly acid; clear wavy boundary. (8 to 15 inches thick) Btx3--42 to 52 inches; light yellowish brown (10YR 6/4) cobbly loam; many distinct yellowish brown (10YR 5/8) and light brownish gray (2.5Y 6/2) mottles; weak very coarse prismatic structure parting to weak coarse platy; very firm, brittle; few distinct clay films; numerous fine pores; 25 percent sandstones cobbles; very strongly acid; clear wavy boundary. (0 to 12 inches thick) C--52 to 65 inches; mixed strong brown (7.5YR 5/8) and light gray (N 7/ ) clay loam, pale yellow (2.5Y 7/4) crushed massive; firm; 35 percent weathered shale, sandstone fragments and cobbles; very strongly acid; clear smooth boundary. 15
Distribution of Soil Orders The distribution of Soil Orders depends on all of the 5 factors of soil formation S = ƒ (Cl,O,R,P,T) Climate has the most influence on a global or continental scale Climate Climate Soil Orders Soil Orders - USA 16
Soil Orders. Entisols Ent For Recent; Very Little Development New Surficial Deposits Soil Orders cont. Inceptisols Incept for inception Cambic Horizon Soil Orders cont. Alfisols Alf for Aluminum Al and Iron Fe Argillic horizon, high (>35%) base saturation Well-developed soil Common West Virginia soil 17
Alfisol Wisconsin J.S. Kite Photo Ultisols Soil Orders cont. Ult for ultimate Highly weathered, but less than Oxisols Argillic horizon & low (<35%) base saturation Dominant soil type in SE USA Ultisol http://www.statlab.iastate.edu/ soils/photogal/orders/soiord.htm 18
Ultisol Shenandoah Valley, Virginia 70 ft J.S. Kite Photo Soil Orders, cont. Oxisols oxi for oxides Red soils due to oxidized iron Highly weathered Warm, moist tropics Oxisol 19
Oxisol Cornfield Mollisol Shenandoah Valley, Virginia J.S. Kite Photo Mollisol Great Plains Calcite 20
Soil Orders cont. Spodosols Light-colored E horizon & Dark illuvial B horizon Mostly loamy to sandy soils Common in acidic soils of coniferous forests - organic acids aid translocation Spodosols at high elevation in WV J.S. Kite Photo Spodosol Allagash River Terrace, Maine Soil Orders cont. Vertisols Vert for invert Contain smectite Shrink-swell properties causes Turnover Slickensides, Tee-pee Structures Texas Gulf Coast 21
Vertisol, Zambia Soil Orders cont. Aridisols Dryland Soils Highly alkaline (high ph), commonly saline Typical in SW U.S. 2008 Find Better aridisol Pic 22
Aridisol Soil Orders cont. Histosols Hist means fiber Dark, organic soils May be muck or peat Anaerobic, Negative Eh Highly acidic Histosol, Carrying Place Bog, Maine J.S. Kite Photo 23
New (1998) Soil Orders Andisols Soils in Tephras Gelisols Soils Under Permafrost) Andisol Aquic Vitrixerands Washington http://www.statlab.iastate. edu/soils/photogal/ statesoils/wa_soil.htm J.S. Kite Photo Gelisol: Victoria Valley, Antarctica 24
Gelisol http://www.statlab.iastate.edu/ soils/photogal/orders/soiord.htm Proposed Soil Order Anthrosols Proposed soil order for artificially disturbed material 25