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Hydrothermal dolomitization and recrystallization of dolomite breccias from the Miocene Monterey Formation, Tepusquet area, California

Journal Article · · Journal of Sedimentary Research, Section A: Sedimentary Petrology and Processes
OSTI ID:445632
;  [1];  [2]
  1. Duke Univ., Durham, NC (United States). Dept. of Geology
  2. Univ. Bern (Switzerland). Geologisches Inst.
Despite the intensity of brecciation and its potential importance as an analog to Monterey fractured hydrocarbon reservoirs, no detailed petrographic, crystallographic, or geochemical analyses have been performed on the breccias from the Tepusquet area. In the present study, petrographic, crystallographic, and geochemical analyses show that the vein-filling dolomites were precipitated from hydrothermal fluids that were associated with hydrocarbon migration, and that the early diagenetic matrix dolomites have been recrystallized, resetting their geochemical and crystallographic properties. The close chemical similarity of the vein dolomites and the most recrystallized matrix dolomites, the episodic association between hydrocarbons and the vein dolomites, and the recrystallization trends in the matrix dolomites, all indicate that evolved formation waters were the source of the hydrothermal fluids that precipitated the vein dolomites.
OSTI ID:
445632
Journal Information:
Journal of Sedimentary Research, Section A: Sedimentary Petrology and Processes, Journal Name: Journal of Sedimentary Research, Section A: Sedimentary Petrology and Processes Journal Issue: 5 Vol. 66; ISSN JSRAEA; ISSN 1073-130X
Country of Publication:
United States
Language:
English