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dc.contributor.authorHolbrook, W. Stevenen
dc.contributor.authorMarcon, Virginiaen
dc.contributor.authorBacon, Allan R.en
dc.contributor.authorBrantley, Susan L.en
dc.contributor.authorCarr, Bradley J.en
dc.contributor.authorFlinchum, Brady A.en
dc.contributor.authorRichter, Daniel D.en
dc.contributor.authorRiebe, Clifford S.en
dc.description.abstractAs bedrock weathers to regolith -defined here as weathered rock, saprolite, and soil - porosity grows, guides fluid flow, and liberates nutrients from minerals. Though vital to terrestrial life, the processes that transform bedrock into soil are poorly understood, especially in deep regolith, where direct observations are difficult. A 65-m-deep borehole in the Calhoun Critical Zone Observatory, South Carolina, provides unusual access to a complete weathering profile in an Appalachian granitoid. Colocated geophysical and geochemical datasets in the borehole show a remarkably consistent picture of linked chemical and physical weathering processes, acting over a 38-m-thick regolith divided into three layers: soil; porous, highly weathered saprolite; and weathered, fractured bedrock. The data document that major minerals (plagioclase and biotite) commence to weather at 38 m depth, 20 m below the base of saprolite, in deep, weathered rock where physical, chemical and optical properties abruptly change. The transition from saprolite to weathered bedrock is more gradational, over a depth range of 11-18 m. Chemical weathering increases steadily upward in the weathered bedrock, with intervals of more intense weathering along fractures, documenting the combined influence of time, reactive fluid transport, and the opening of fractures as rock is exhumed and transformed near Earth's surface.en
dc.description.sponsorshipNational Science Foundation (NSF) [EPS 1208909]en
dc.description.sponsorshipDepartment of Energy Office of Basic Energy Sciences [DE-FG02-05ER15675]en
dc.description.sponsorshipSusquehanna/Shale Hills and Luquillo Critical Zone Observatory [NSF EAR 1339285, 1331726, NSF EAR 1331841]en
dc.description.sponsorshipDuke Universityen
dc.description.sponsorshipCalhoun Critical Zone Observatory [NSF EAR 1331846]en
dc.publisherSpringer Natureen
dc.rightsCreative Commons Attribution 4.0 Internationalen
dc.titleLinks between physical and chemical weathering inferred from a 65-m-deep borehole through Earth's critical zoneen
dc.typeArticle - Refereeden
dc.description.notesW.S.H., B.J.C., B.A.F. and C.S.R acknowledge support from the National Science Foundation (NSF) Grant Number EPS 1208909. S.L.B. acknowledges support from funding from the Department of Energy Office of Basic Energy Sciences grant DE-FG02-05ER15675 to SLB and from the Susquehanna/Shale Hills and Luquillo Critical Zone Observatory (NSF EAR 1339285 and 1331726 to S.L.B. and NSF EAR 1331841 to W.H. McDowell at the University of New Hampshire). D.D.R. acknowledges support from Duke University and the Calhoun Critical Zone Observatory (NSF EAR 1331846). C.S.R. acknowledges support from 1331939.en
dc.title.serialScientific Reportsen

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