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Weathering of phosphorus in black shales
Author(s) -
Kolowith Lauren Clark,
Berner Robert A.
Publication year - 2002
Publication title -
global biogeochemical cycles
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.512
H-Index - 187
eISSN - 1944-9224
pISSN - 0886-6236
DOI - 10.1029/2001gb001887
Subject(s) - weathering , oil shale , geology , soil production function , erosion , geochemistry , total organic carbon , sink (geography) , phosphorus , environmental chemistry , mineralogy , soil science , chemistry , geomorphology , soil water , pedogenesis , paleontology , cartography , organic chemistry , geography
Rock weathering is the ultimate source of phosphorus (P) to the oceans, where P can be a limiting nutrient for biological production. In this paper, P weathering is examined in soil chronosequences formed in weathering profiles on the organic‐rich Woodford Shale, New Albany Shale and Green River Shale. At all sites, organic P and inorganic P concentrations reveal that P weathering is far from complete, prior to erosion. Carbon (C)/P ratios decrease significantly from unweathered shale to the weathered shale at all sites, which is driven by loss of total organic C with weathering. Here we characterize organic phosphorus across a weathering profile from the Woodford Shale using solid‐state CPMAS 31 P NMR spectroscopy techniques, revealing that P esters are the dominant forms of P during all stages of weathering. Certain P esters appear to be resistant to chemical weathering during the millions of years between deposition, uplift and erosion, possibly representing a significant long‐term global sink for P.