69 Structural Geology (Posters)

Saturday, 27 March 2004
8:00 AM - 12:00 PM

RHYTHM OF THE WRINKLES: A NEWLY MAPPED ANTICLINCE WITHIN THE BEDFORD SYNCLINORIUM OF EASTERN WEST VIRGINA

Paper number: 69-9
Program: Technical Sessions
Time: 8:00 AM – 12:00 PM

Authors

  • John M. Dennison Presenting Author
    Univ of North Carolina at Chapel Hill, Chapel Hill, NC

Abstract

Valley and Ridge structures contain various wavelengths of folds, depending on the lithotectonic details of stratigraphic packages, resulting in successively smaller folds nested within larger ones. Plunging folds commonly interfinger, somewhat analogous to interfering multiple waves on water. Such a pattern brings Oriskany Sandstone up in anticlines about 3-5 km apart superimposed on the taller Wills Mountain and Patterson Creek Mountain anticlines. One notable exception is the broad and flat Bedford syncline, unless Upper Devonian siliciclastic beds contain an unmapped anticline. Search for such a rhythm revealed in Mineral and Grant counties an unknown fold traversed across its middle by Mikes Run (hence the name Mikes Run anticline) and also near its north end by U. S. Route 50.

This doubly plunging anticline is outlined by the Minnehaha Springs Member (a bundle in the base of the Scherr Formation about 18 m thick with much fine sandstone and locally containing red mudstone), forming a wrap-around envelope 14 km long. The core of the Mikes Run anticline is slightly lower terrain of Brallier Formation. To the west is the newly mapped Tucker Ridge syncline, which locally contains basal Foreknobs Formation (Mallow Member) at Tucker Ridge. To the east of the Mikes Run anticline is the newly mapped Dry Run syncline. Maximum width of the Mikes Run anticline is 2.9 km, and its maximum structural height is about 550 m. The flanks of this anticline may contain local faulting. A geologic map of the Mikes Run anticline is on open-file with the West Virginia Geological and Economic Survey.