Geology Reports⌕ Search

Geology topics

William C. Burton

Publications and source records attributed to William C. Burton.

42 records · Page 3Linked to original sources
USGS1995

Geology of the Waterford quadrangle, Virginia and Maryland, and the Virginia part of the Point of Rocks quadrangle

The bedrock geology of the Waterford quadrangle and of the Virginia part of the Point of Rocks quadrangle consists of a portion of the Middle Proterozoic basement core and its cover sequence on the eastern limb of the Blue Ridge anticlinorium and the adjacent early Mesozoic Culpeper basin. The three major rock associations in this area are: 1) Middle Proterozoic gneisses intruded by late Proterozoic metadiabase dikes, 2) unconformably overlying late Proterozoic and early Paleozoic metavolcanic and metasedimentary rocks, and 3) Upper Triassic sedimentary strata intruded by early Jurassic diabase. The Triassic and Jurassic rocks are separated from the older rocks by a major normal fault, the Bull Run fault. Late Cenozoic surficial deposits of three major types unconformably overlie the bedrock: colluvium derived from Catoctin Mountain, terrace deposits of the Potomac River, and flood plain alluvium of the Potomac River and its tributaries. -from Authors

Maryland, Virginia↗
USGS1995

Preliminary geologic map of the Lunenburg and Fort Mitchell 7.5' quadrangles, Virginia

The Lunenburg and Fort Mitchell 7.5' quadrangles have been mapped as part of the Geology of the South-Central Virginia Piedmont Project, a regional geologic mapping project of the U.S. Geological Survey. The two quadrangles include parts of Lunenburg, Mecklenburg, and Charlotte counties, and are located in the east-central part of the South Boston 30'x60' quadrangle (Figure 1). A preliminary geologic map of this quadrangle has been published (Norton and others, 1993), and a reconnaissance map by Laney (1917) includes the western Fort Mitchell quadrangle. Aeromagnetic and aeroradioactivity maps that include the field area have been published by the U.S. Geological Survey (1978a, 1978b). The Lunenburg and Fort Mitchell quadrangles are adjacent to the north and northwest, respectively, to the previously mapped Wightman 7.5' quadrangle (Burton, 1993; Figure 1). With respect to geologic provinces, the Lunenburg and Fort Mitchell quadrangles are located within the Carolina slate belt of the Carolina Terrane (Figure 1) and have not been previously mapped in detail. The Carolina slate belt in this area consists of volcanic and sedimentary rocks and associated intrusive igneous rocks that possess a regional slatey cleavage and have been subjected to lower greenschistfacies metamorphism. An earlier, pre-cleavage deformation and low-grade metamorphism may have occurred in the Late Proterozoic (Glover and Sinha, 1973). The rocks are locally poorly dated but probably are Late Proterozoic and Early Cambrian in age (Butler and Secor, 1991, and references therein). The Carolina slate belt may represent a subduction-related volcanic arc (Butler and Secor, 1991), or riftedarc complex (Feiss and others, 1993). Geochemical analysis and radioisotopic dating (U-Pb and 40 Ar/ 39 Ar) of slate belt rocks in the South Boston 30 x 60' quadrangle by the U.S.G.S. are in progress.

Virginia↗