Depositional system and source rock potential of the Sharon Springs Formation in Colorado
The Sharon Springs Member of the Pierre Shale has recently been divided and reclassified as the Gammon Ferruginous Formation and Sharon Springs Formation, with the Pierre Shale being upgraded to group status. Deposition took place between 82 and 77 Ma in a conformable succession of facies following the Niobrara Highstand, and an overall progradation of siliciclastics into the Western Interior Seaway. These units gradually decrease over time in calcite content associated with chalk filled fecal pellets, to clay and quartz dominated deposits with a large constituent of pyrite. This interval has ...
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