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Chemical Weathering, Soil Development, and Geochemical Fractionation in a Part of the White Mountains, Mono and Inyo Counties, California

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Chemical Weathering, Soil Development, and Geochemical Fractionation in a Part of the White Mountains, Mono and Inyo Counties, California Chemical Weathering, Soil Development, and Geochemical Fractionation in a Part of the White Mountains, Mono and Inyo Counties, California GEOLOGICAL SURVEY PROFESSIONAL PAPER 352-J Chemical Weathering, Soil Development, and Geochemical Fractionation in a Part of the White Mountains, Mono and Inyo Counties, California By DENIS E. MARCHAND EROSION AND SEDIMENTATION IN A SEMIARID ENVIRONMENT GEOLOGICAL SURVEY PROFESSIONAL PAPER 352-J UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON: 1974 UNITED STATES DEPARTMENT OF THE INTERIOR ROGERS C. B. MORTON, Secretary GEOLOGICAL SURVEY V. E. McKelvey, Director Library of Congress catalog-card No. 73-600361 For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 - Price $1-35 (paper cover) Stock Number 2401-02484 CONTENTS Page Page Abstract ________________________________ 379 Chemical weathering and soil development Continued Introduction _____________________________ 379 Chemical weathering Continued Study area _______________________________ 381 Changes in the solid phases Continued Location and description ___________________ 381 Chemical changes from bedrock to soil ______ 400 Previous work in the region __________________ 382 Reed Dolomite __________________ 401 Climate _____________________________ 382 Adamellite of Sage Hen Flat ________ 403 Vegetation ____________________________ 384 Changes in the liquid phase _______________ 405 Geology _____________________________ 385 Chemical composition of precipitation ______ 405 Chemical weathering and soil development___________ 388 Chemical composition of soil water __ __406 Method of approach_______________________ 388 Soil pH ________._______._____. 406 Field methods _________________________ 388 Exchangeable cations ______________ _ 406 Laboratory methods _____________________ 388 Chemical composition of spring waters ______ 407 Description of soils _______________________ 389 Waters related in part to the Clarification of terms ___________________ 389 Reed Dolomite ________________ 407 Reed Dolomite soils____________________ 390 Waters related largely to the adamellite of Adamellite soils of Sage Hen Flat ___________ 390 Sage Hen Flat __.______________ 408 Basalt soils _________________________ 391 Analysis of chemical changes ___ ____ __ __408 Andrews Mountain sandstone soils __________ 391 Relative mobilities _______________ 408 Soil contamination _______________________ 392 Stability with respect to solid Physical weathering _____________________ 392 and gas phases ________________ 409 Reed Dolomite _______________________ 392 Relation of soil water to precipitation Adamellite of Sage Hen Flat ______________ 393 and spring waters _____ _ 411 Mechanisms of disintegration ______________ 394 Chemical weathering _____________________ 395 Chemical fractionation in the bedrock-soil-water-plant Changes in the solid phases _______________ 395 system________________________________413 Mineralogical changes _______________ 395 Summary and discussion _____________ ______ 416 Reed Dolomite __________________ 395 Weathering of Reed Dolomite ________________ 417 Adamellite of Sage Hen Flat ________ 396 Weathering of adamellite of Sage Hen Flat ________ 417 Electron microprobe studies of adamellite General weathering relations ________________ 418 mineral weathering _________ 398 Biotites __________________ 398 References cited __ ___ 418 Feldspars ____________________ 400 Supplemental information Methods, reproducibility, Other minerals______________ _ 400 and accuracy ___ ___ 422 ILLUSTRATIONS Page FIGURE 269. Diagram showing reversible, irreversible, and cyclical processes associated with weathering and erosion ______ 380 270. Map of east-central California and adjacent part of Nevada, indicating location of the study area _________ __ 381 271. Photograph showing part of the upland surface in the White Mountains __________________ __________ 381 272. Map of generalized topography of a part of the southern White Mountains _________________ __ _ 381 273. Photograph showing North Sage Hen Flat auxiliary weather station and dust trap ___________ 383 274. Graph showing maximum and minimum temperature and relative evaporation rates at Crooked Creek Laboratory and five auxiliary weather stations ______________________ - 384 275. Graph showing precipitation recorded at Crooked Creek Laboratory and at five auxiliary weather stations 384 276. Photograph showing vegetational contrast between dolomite outcrops and colluvium and sandstone colluvium 385 277. Generalized geologic map of the study area _____________________________ _____ __________ 386 278. Photograph showing view north across Sage Hen Flat, showing degraded White Mountain erosion surface and outcrop areas of adamellite of Sage Hen Flat, Reed Dolomite, and Andrews Mountain sandstone _____ 387 279. Photograph showing view east from Sage Hen Flat, showing resistant basalt capping less resistant metasediments and granitic intrusive rock ______________________________________________ _______ 387 III IV CONTENTS Page FIGURE 280. Photograph showing exposures of reworked rhyolitic ash interbedded with terrace alluvium along Croloked Creek 387 281 -284. Maps showing: 281. Depth of soil and colluvium at planetable map site R-l, Reed Dolomite, 10,600 feet ___________ 389 282. Depth of soil and colluvium at planetable map site R-2, Reed Dolomite, 11,200 feet ______________ 390 283. Depth of soil and colluvium at planetable map site S-l, adamellite of Sage Hen Flat _ _. ___ 390 284. Depth of soil and colluvium at planetable map site B-l. on basalt _______________,_______ 391 285. Photograph showing Reed Dolomite soil pit ________________________________ 391 286. Photograph showing soil pit in'adamellite of Sage Hen Flat ______________________ - - 391 287. Graph showing cumulative grain size frequency curves for dolomite soils and comparison with ranges i|n bedrock grain size ___________________________________________________________ 392 288. Diagram showing gravel-sand-silt and clay distribution for soil above the C horizon __________ ______ 392 289. Diagram showing sand-silt-clay distribution for soil above the C horizon __________________ ______ 393 290. Photograph of weathered adamellite outcrop on Sage Hen Flat ________________________ 393 291. Graph showing cumulative grain size frequency curves for adamellite soils and comparison with ranges of bedrock grain size ___________________________________________________________________ 394 292. Photomicrographs showing fresh, crushed bedrock dolomite and etched, embayed, altered soil dolomite grain ____ 395 293. Photomicrographs showing fresh, crushed bedrock talc and soil talc grains ____________________________ 396 294. Diagram showing mineral weathering sequence in Reed Dolomite soils, in order of decreasing resistance ___ 396 295. Photomicrograph of weathered grains in adamellite soil thin section __________________ 397 296. Photomicrograph of soil biotite grains ___________________________________________________ 397 297. Diagram showing mineral weathering sequence in adamellite soils of Sage Hen Flat in ord|er of decreasing resistance _____________________________________________________ ._________ 398 298-301. Graphs showing: 298. Electron microprobe traverses normal to (001) cleavage of two soil biotite grains _______h_____ __ __ 399 299. Electron microprobe traverses parallel to (001) cleavage of two soil biotite grains _________________ 399 300. Electron microprobe analyses of 10 parts of a single plagioclase grain _____________ ______ 400 301. Percentage chemical losses for the indicated Reed Dolomite and adamellite soils of Sage Hen Flat with re­ spect to bedrock ___________________________________________ __________ 402 302. Photograph of rock saw chips showing weathering rind on spheroidally weathered dolomite analyzed by electron microprobe _______________________________________________________________ 403 303 -308. Graphs showing: 303. Electron microprobe transect showing Ca, Mg, and Fe variation across an alteration rind in spheroidally weathered Reed Dolomite _____________________________________,__________ 403 304. Electron microprobe transect for Ca, Mg, and Mn across same dolomite weathering rindl __________ 403 305. Mineral percentage changes with respect to bedrock in two size fractions of a relatively uncontaminated adamellite soil ____________________________________________ __________ 404 306. Relative mobilities for eight elements in spring waters related to adamellite _________ 409 307. Stability diagram for Na silicates ____________________________________ 411 308. Stability diagram for K silicates _____________________________________ __________ 411 309. Compositional diagram showing progressive cation changes from precipitation water to soil and spring waters related to Reed Dolomite ________________________________________________ __________ 412 310. Compositional diagram showing progressive cation changes from precipitation water to soil and spring waters related to adamellite __________________________________________________ __________ 412 311-314- Graphs showing: 311. Mg/Fe and Ca/Fe ratio comparisons of waters related to adamellite ______________ __________ 413 312. Silica-cation ratio comparisons of adamellite-related waters ____________________ ______ 413 313. Comparison of elemental and total concentrations in soil, soil water, colloidal exchange, and plants 415 314. Fractionation of nine elements in the adamellite bedrock-soil-water-plant system _______i______
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