TY - JOUR
T1 - ISOTOPIC AND CHEMICAL EVOLUTION OF MINERALIZATION IN SEPTARIAN CONCRETIONS
T2 - EVIDENCE FOR EPISODIC PALEOHYDROGEOLOGIC METHANOGENESIS.
AU - Siegel, D. I.
AU - Chamberlain, Steven C.
AU - Dossert, William P.
PY - 1987
Y1 - 1987
N2 - Detailed chemical and isotopic studies of mineralization of septarian fractures in concretions in the Devonian Marcellus Shale document a complicated paragenesis involving multiple episodes of metal-carbonate precipitation during methane fermentation. It is proposed (1) that a first period of methane fermentation occurred during burial and diagenesis in the Devonian, (2) that a second period occurred as strontium-bearing Silurian brines were displaced upward near the toe of Pleistocene glaciation, and (3) that witherite replaced barite during sulfate reduction and another period of methane fermentation in a Pleistocene mixture of reducing conditions below thick ice cover. Fluid-inclusion data, oxygen-isotope values of carbonate minerals, and strontium-isotope ratios are all consistent with these suggestions.
AB - Detailed chemical and isotopic studies of mineralization of septarian fractures in concretions in the Devonian Marcellus Shale document a complicated paragenesis involving multiple episodes of metal-carbonate precipitation during methane fermentation. It is proposed (1) that a first period of methane fermentation occurred during burial and diagenesis in the Devonian, (2) that a second period occurred as strontium-bearing Silurian brines were displaced upward near the toe of Pleistocene glaciation, and (3) that witherite replaced barite during sulfate reduction and another period of methane fermentation in a Pleistocene mixture of reducing conditions below thick ice cover. Fluid-inclusion data, oxygen-isotope values of carbonate minerals, and strontium-isotope ratios are all consistent with these suggestions.
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U2 - 10.1130/0016-7606(1987)99<385:TIACEO>2.0.CO;2
DO - 10.1130/0016-7606(1987)99<385:TIACEO>2.0.CO;2
M3 - Article
AN - SCOPUS:0023525521
SN - 0016-7606
VL - 99
SP - 385
EP - 394
JO - Bulletin of the Geological Society of America
JF - Bulletin of the Geological Society of America
IS - 3
ER -