Paleoenvrironmental Controls on Diagenesis of Organich-Rich Shales in the Eagle Ford Group

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dc.contributorTice, Michael M
dc.creatorKruse, Kendra
dc.date.accessioned2015-04-28T15:21:35Z
dc.date.accessioned2017-04-07T20:13:15Z
dc.date.available2015-04-28T15:21:35Z
dc.date.available2017-04-07T20:13:15Z
dc.date.created2014-12
dc.date.issued2014-08-27
dc.description.abstractCarbonate precipitation can be either promoted or inhibited by microbial processes in different redox zones. It is therefore possible for basin redox evolution to indirectly control early carbonate diagenesis and modify reservoir properties of corresponding shale units. The goals of this study were to analyze geochemical characteristics of the Late Cretaceous Eagle Ford Group in McMullen County, Texas to test the hypotheses that (1) the redox state of the water column controlled carbonate cement abundance and (2) carbonate cement lowered organic matter content by volumetric dilution. An x-ray analytical microscope was used to map elemental compositions of fresh core samples within the Eagle Ford Group. Resultant maps were used to characterize carbonate cements and to estimate the redox state of the overlying water column during deposition, as indicated by the relative abundances of the trace metals Mo, V, and Cr. Results indicate that cementation occurred early relative to compaction. Ti Kal normalized Mo Kal and CaKal fluorescence intensities are positively correlated throughout the unit, suggesting that carbonate cementation was related to the redox state. Total organic carbon is negatively correlated in the upper Lower Eagle Ford with (Ca Kal)/(Ti Kal) fluorescence ratio, consistent with volumetric dilution of organic matter by diagenetic cementation prior to compaction. In contrast, there is no significant correlation between total organic carbon and carbonate content in the more organic-rich Lower Eagle Ford.
dc.identifier.urihttp://hdl.handle.net/1969.1/153852
dc.language.isoen
dc.subjectGeochemistry
dc.subjectchemostratigraphy
dc.subjectXRF
dc.subjectEagle Ford
dc.subjectwater column chemistry
dc.subjectpetroleum
dc.subjectdiagenesis, carbonate precipitation
dc.subjectcarbonate cementation
dc.subjectcarbonate
dc.subjectshale
dc.subjectorganics
dc.subjectredox
dc.subjectmicrobial respiration
dc.titlePaleoenvrironmental Controls on Diagenesis of Organich-Rich Shales in the Eagle Ford Group
dc.typeThesis

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