46 Stratigraphy and Sedimentology

Monday, 15 March 2010
3:35 PM - 5:35 PM
Hopkins

LATE DEVONIAN STRATIGRAPHY AND PALEONTOLOGY NEAR ELKINS, WEST VIRGINIA

Paper number: 46-3
Program: Technical Sessions
Time: 4:15 PM – 4:35 PM

Authors

Abstract

Roadcut outcrops west of Elkins, WV, provide almost continuous exposure of Late Devonian strata. Lithologically there is a rapid transition from fossiliferous marine siltstones to shallow marine fossil hashes, redbeds, conglomerates, and other terrestrial deposits. Work by McGhee tied the Frasnian-Famennian (F-F) extinction boundary to the sands of the Pound Member of the Foreknobs Formation. Biostratigraphic analysis shows a distinct termination of Frasnian Stage index fossils near a coarse bundle within the marine siltstone, presumably the deep water equivalent of the Pound Member. The outcrop has not yielded a distinct Famennian Stage fauna so the F-F boundary is only tentatively placed at the coarse siltstone bundle. Above the marine silststones are shale redbeds and conglomerates lacking marine fossils which are probably equivalent to the Famennian age Hampshire and Price Formations. Within this sequence is a distinct layer of carbonized wood suggesting a Late Devonian-Early Mississippian forest fire.

Exposures at nearby Huttonsville, WV, have marine fossils extending up to 580 meters above the Pound Member sandstone, while west of Elkins non-marine strata begin 210 meters above the coarse siltstone bundle. If the coarse bundle is Pound equivalent, it indicates much more rapid shallowing near the end of the Devonian at Elkins than at Huttonsville.