Stratigraphy, structure and regional correlation of eastern Blue Ridge sequences in southern Virginia and northwestern North Carolina: an interim report from new USGS mapping

GSA Field Guides
By:  and 

Links

Abstract

Examination of key outcrops in the eastern Blue Ridge in southern Virginia and northwestern North Carolina is used to evaluate existing stratigraphic and structural models. Recent detailed mapping along the Blue Ridge Parkway and the eastern flank of the Mount Rogers massif provides the opportunity to (1) evaluate legacy data and interpretations and (2) formulate new ideas for regional correlation of eastern Blue Ridge geology.

Lynchburg Group rocks in central Virginia (metagraywacke, quartzite, graphitic schist, amphibolite, and ultramafic rocks) carry southward along strike where they transition with other units. Wills Ridge Formation consists of graphitic schist, metagraywacke, and metaconglomerate, and marks the western boundary of the eastern Blue Ridge. The Ashe Formation consists of conglomeratic metagraywacke in southern Virginia, and mica gneiss, mica schist, and ultramafic rocks in North Carolina. The overlying Alligator Back Formation shows characteristic compositional pin-striped layers in mica gneiss, schist, and amphibolite.

The contact between eastern Blue Ridge stratified rocks above Mesoproterozoic basement rocks is mostly faulted (Gossan Lead and Red Valley). The Callaway fault juxtaposes Ashe and Lynchburg rocks above Wills Ridge Formation. Alligator Back Formation rocks overlie Ashe and Lynchburg rocks along the Rock Castle Creek fault, which juxtaposes rocks of different metamorphism. The fault separates major structural domains: rocks with one penetrative foliation in the footwall, and pin-striped recrystallized compositional layering, superposed penetrative foliations, and cleavage characterize the hanging wall. These relationships are ambiguous along strike to the southwest, where the Ashe and Alligator Back formations are recrystallized at higher metamorphic grades.

Study Area

Publication type Article
Publication Subtype Journal Article
Title Stratigraphy, structure and regional correlation of eastern Blue Ridge sequences in southern Virginia and northwestern North Carolina: an interim report from new USGS mapping
Series title GSA Field Guides
DOI 10.1130/2014.0035(07)
Volume 35
Year Published 2014
Language English
Publisher Geological Society of America
Publisher location Boulder, CO
Contributing office(s) Eastern Geology and Paleoclimate Science Center
Description 27 p.
First page 215
Last page 241
Country United States
State North Carolina, Virginia
Online Only (Y/N) N
Additional Online Files (Y/N) N
Google Analytic Metrics Metrics page
Additional publication details