thumbnail

Geologic Map of the Buckner 7.5-Minute Quadrangle, Louisa County, Virginia

Scientific Investigations Map 3533
Prepared in cooperation with the Virginia Department of Energy, Geology and Mineral Resources Program
By: , , , , , , , , , and 
https://doi.org/10.3133/sim3533

Links

Abstract

The Buckner 7.5-minute quadrangle straddles three terrane boundaries in the Piedmont Physiographic Province in central Virginia: the Chopawamsic terrane, the Elk Hill Complex, and the Goochland terrane. In much of the map area, the Elk Hill Complex separates the Chopawamsic and Goochland terranes. Rocks of the Chopawamsic terrane include Ordovician metavolcanic and metasedimentary rocks of the Chopawamsic Formation, Ordovician to Silurian granodiorite sheet intrusions, and Paleozoic mafic intrusions. Silurian to Devonian rocks of the Quantico Formation, mostly garnet-mica schist, crop out in the northwesternmost part of the map area, and are in unconformable contact with rocks of the Chopawamsic Formation on the southeastern limb of the Quantico synclinorium. The main map unit in the Elk Hill Complex is Neoproterozoic mica gneiss, which is in pre-metamorphic fault contact with rocks of the Chopawamsic Formation to the west. The main map unit of the Goochland terrane is the Maidens Gneiss. Except for Jurassic diabase dikes, all rocks on the Buckner 7.5-minute quadrangle were metamorphosed to amphibolite facies during the Alleghanian orogeny and preserve multiple compositional and phyllosilicate penetrative foliations. Evidence of amphibolite-facies metamorphism during the Taconic orogeny is preserved in rocks of the Elk Hill Complex. The entire width of the Maidens Gneiss on the Buckner 7.5-minute quadrangle is within the Spotsylvania high-strain zone and amphibolite-facies mylonitic textures are pervasive. Quartz veins and Jurassic diabase dikes crosscut all older rocks of the quadrangle.

Multiple levels of terrace deposits are present along and near the major streams of the quadrangle. The lower terrace deposits are likely remnants of former positions of the Little River on the landscape, whereas higher deposits may be remnants of former deposits of the Atlantic Coastal Plain that covered this portion of the Piedmont Province. A linear cluster of aftershocks from the magnitude 5.8 earthquake that occurred near Mineral, Virginia, in 2011 defines the Fredericks Hall fault, which is at depth on the Buckner quadrangle. Most of the aftershocks occurred in the core of the Elk Creek antiform and have no relation to faults mapped at the surface. Several abandoned crushed stone and building stone quarries, as well as a mica prospect, exist in the quadrangle.

Suggested Citation

Carter, M.W., Spears, D.B., Latane, V.M., Crider, E.A., Weinmann, B.R., Mangum, H., McAleer, R.J., Horton, J.W., Jr., Shah, A.K., and Regan, S.P., 2025, Geologic map of the Buckner 7.5-minute quadrangle, Louisa County, Virginia: U.S. Geological Survey Scientific Investigations Map 3533, 1 sheet, scale 1:24,000, 37-p. pamphlet, https://doi.org/10.3133/sim3533.

ISSN: 2329-132X (online)

Study Area

Table of Contents

  • Abstract
  • Introduction
  • Geologic Setting
  • Lithology and Stratigraphy
  • Structure
  • Metamorphism
  • Economic Geology
  • References Cited
Publication type Report
Publication Subtype USGS Numbered Series
Title Geologic map of the Buckner 7.5-Minute quadrangle, Louisa County, Virginia
Series title Scientific Investigations Map
Series number 3533
DOI 10.3133/sim3533
Year Published 2025
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Florence Bascom Geoscience Center
Description Pamphlet: vii, 37 p.; 1 Sheet: 48.32 x 41.31 inches; 2 Data Releases
Country United States
State Virginia
County Louisa County
Other Geospatial Buckner 7.5' quadrangle
Online Only (Y/N) Y
Additional Online Files (Y/N) Y
Google Analytic Metrics Metrics page
Additional publication details