BEDROCK GEOLOGIC MAPPING OF THE WESTERN HALF OF THE MONTEREY SE 7.5-MINUTE QUADRANGLE, VIRGINIA
Contrary to previous interpretations of a southeast-dipping thrust along Buck Hill, our mapping suggests that the fault involves primarily the Silurian Tuscarora and Rose Hill Formations and is antithetic, dipping northwest with a northeast-southwest strike. This structure results in localized duplications of the Tuscarora section and thickening of the Rose Hill. Additional evidence for the fault and its geometry include float blocks of hematitic sandstone cataclasite and an outcrop with lenses of cataclasite near continuous beds of the Silurian Williamsport Sandstone.
Part of the mapping project included scrutiny of the nomenclature of the Ordovician carbonate sequence, as the multitude of previous stratigraphic names had been primarily based on faunal content. In an effort to divide the strata into easily identifiable and mappable lithostratigraphic units, and following much field work, the various formations between the Ordovician Beekmantown and Dolly Ridge Formations were mapped as an undivided sequence of carbonate strata. This was deemed the most appropriate choice for mapping these strata until future work allows for identification of stratigraphic contacts that are suitable for field observation and identification while mapping at the 1:24,000 scale.