DOI: 10.1029/2017GB005798
论文题名: Pyrite Oxidation Drives Exceptionally High Weathering Rates and Geologic CO2 Release in Mountaintop-Mined Landscapes
作者: Ross M.R.V. ; Nippgen F. ; Hassett B.A. ; McGlynn B.L. ; Bernhardt E.S.
刊名: Global Biogeochemical Cycles
ISSN: 0886-6236
EISSN: 1944-9224
出版年: 2018
卷: 32, 期: 8 语种: 英语
英文关键词: bedrock
; biogeochemistry
; carbon dioxide
; chemical weathering
; coal combustion
; coal mining
; denudation
; oxidation
; pyrite
; sulfuric acid
学科: carbon
; coal
; mining
; pyrite
; sulfur
; Weathering
中文摘要: Weathering is the ultimate source of solutes for ecosystems, controls chemical denudation of landscapes, and drives the geologic carbon cycle. Mining and other land-moving operations enhance physical weathering by bringing large volumes of shattered bedrock to the surface. Yet, the relative influence of these activities on chemical weathering remains poorly constrained. Here we show that catchments impacted by mountaintop removal coal mining have among the highest rates of chemical weathering ever reported. Mined catchments deliver more than 7,600 kg·ha−1·year−1 of dissolved solids downstream. The chemical signatures of these exceptionally high weathering rates reflect the product of sulfuric acid weathering of carbonate-bearing rock, driven by the oxidation of pyritic materials. As this strong acid rapidly weathers surrounding carbonate materials, H+ ions are consumed and Ca2+, Mg2+, and HCO3 − ions are exported to balance the elevated SO4 2− exports, generating alkaline mine drainage. The sulfate exports from pyrite oxidation in mountaintop-mined catchments account for ~5–7% of global sulfate derived from pyrite, despite occupying less than 0.006% of total land area. Further, the suite of weathering reactions liberate 100–450 kg of rock-derived C·ha−1·year−1 as CO2, with an additional 90–150 kg C·ha−1·year−1 of C released when HCO3 − reaches the ocean. This rock C release contributes to the high carbon costs of coal combustion. ©2018. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/160210
Appears in Collections: 气候变化与战略
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作者单位: Department of Ecosystem Science and Sustainability, Colorado State University, Fort Collins, CO, United States; Department of Ecosystem Science and Management, University of Wyoming, Laramie, WY, United States; Division of Earth and Ocean Sciences, Nicholas School, Duke University, Durham, NC, United States
Recommended Citation:
Ross M.R.V.,Nippgen F.,Hassett B.A.,et al. Pyrite Oxidation Drives Exceptionally High Weathering Rates and Geologic CO2 Release in Mountaintop-Mined Landscapes[J]. Global Biogeochemical Cycles,2018-01-01,32(8)