Petrology of Upper Mississippian Denmar Formation, Greenbrier Group, East-Central West Virginia: ABSTRACT

Abstract

The Denmar Formation of Randolph County is a package of interbedded marine carbonates and siliciclastics deposited on a broad subsiding carbonate platform. Seven major microfacies are recognized: terrigenous siltstone, dolomitized micrite, pelmicrite, biopelmicrite, quartzose pelmicrite, oosparite, and oomicrite. These microfacies characterize three major paleoenvironments: supratidal, intertidal, and shallow subtidal. Four major diagenetic realms are noted: the low supratidal flat containing evaporites and dolomite; the meteoric zone containing blocky calcite spar; the shallow marine phreatic zone with marine cement and micritized fossil fragments; and the burial zone containing mature stylolites. The Denmar Formation represents a sequence of alternating low-energy, shallowing-upward pelmicrite-mudstone and higher energy, shallowing-upward oosparite-grainstone shelf cycles. The pelmicrite-mudstone cycles are mainly composed of intertidal and supratidal sediment. The oosparite-grainstone cycles are mainly composed of low and higher energy subtidal sediments. Diagenesis occurred in both the marine and meteoric zones. Paleoenvironmental reconstruction of east-central West Virginia during deposition of the Denmar is attempted. End_of_Article - Last_Page 1449------------