Age and Sr isotopic signature of the Catoctin volcanic province: Implications for subcrustal mantle evolution

Geologic map of the Round Hill quadrangle, Clarke and Loudoun Counties, Virginia, and Jefferson County, West Virginia

“…Most workers now agree that the Catoctin Formation is Late Proterozoic in age, based on isotopic dating (Rankin and others, 1969;Badger and Sinha, 1988;see Catoctin Formation below) , and that the fossiliferous Antietam Quartzite is Early Cambrian in age (Hesser, 1938, p.4-6) . Because of their lack of fossils , the Harpers Formation, Weverton Quartzite, and Loudoun Formation have been arbitrarily referred by some workers to the Precambrian (for example, Hesser, 1938;Mitra, 1989) or have been assigned a Cambrian(?)…”

Surficial geology of Shaver Hollow, Shenandoah National Park

“…The entire area of Shaver Hollow is underlain by granitic rocks of Grenville (1.0-1.1 Ga) age, intruded by small dikes related to the Catoctin metavolcanic rocks of 570 ma (Badger and Sinha, 1988). These granitic rocks were first recognized by Jonas (1935), who identified them as hypersthene granodiorites.…”

“…More recent work by Badger and Sinha (1988) and Badger (1993) established the age of the Catoctin at 570 ma and provided new information on the chemistry and origin of these rocks. The chemistry of these rocks is least altered in the dikes, is typical of tholeiite basalts with moderately high titanium content, and is similar to the chemistry of large, extensive plateau basalts.…”

Laurentian margin evolution and the Caledonian orogeny—A template for Scotland and East Greenland

“…This magmatism is contemporaneous with a second pulse of bimodal magmatism throughout the Appalachians (e.g. Badger and Sinha, 1988;Rankin et al, 1989;Aleinikoff et al, 1995) and related to continental break-up in Laurentia (Cawood et al, 2001 Pringle, 1940;Tanner, 1995 Provenance studies summarised here (Fig. 7;Cawood et al, 2003Cawood et al, , 2004 provide useful data that track the evolution and denudation history of the hinterland.…”