Provenance of Sandstones in the Golconda Terrane, North Central Nevada
JONES, ELIZABETH A., University of California, Berkeley, CA
The upper Paleozoic Golconda terrane of north-central Nevada is a composite of several structurally bounded subterranes made of clastic, volcanic, and carbonate rocks. The clastic rocks provide important clues for the interpretation of the provenance and paleogeographic settings of the different lithologic assemblages found in these subterranes.
Two petrographically distinct sandstones are identified in the Golconda terrane in the Osgood Mountains and the Hot Springs Range of north-central Nevada. The sandstone of the Mississippian Farrel Canyon Formation, part of the Dry Hills subterrane, is characterized by quartzose and sedimentary and lithic-rich clasts with a small feldspar component. In contrast, the sandstone of the Permian Poverty Peak (II) subterrane is a silty quartzarenite with no lithic component, and a
very limited feldspar component.
The sandstone of the Farrel Canyon Formation is similar to nonvolcanic sandstones reported from elsewhere in the Golconda terrane. Modal data reflect a provenance of a recycled orogen and permit the interpretation that it could have been derived from the Antler orogen as has been proposed for other sandstones of the Golconda terrane.
The sandstone of the Poverty Peak (II) subterrane is more mature than any of the other sandstones in either the Golconda terrane, the Antler overlap sequence, or the Antler foreland basin sequence. Modal data put the Poverty Peak (II) sandstone in the continental block provenance category. It was not derived from a reworked orogen such as the Antler, containing oceanic-derived sedimentary or volcanic rocks, rather, its source was exclusively cratonal. There is no recognized adjacent early Permian or older formation which could have served as the provenance source for the Poverty Peak (II) sandstone.
The distinct extrabasinal provenances represented in these different sandstones support the idea that the Golconda basin was made up of complex paleogeographic settings, which included multiple sources of extrabasinal sediment.
AAPG Search and Discovery Article #91009©1991 AAPG-SEPM-SEG-SPWLA Pacific Section Annual Meeting, Bakersfield, California, March 6-8, 1991 (2009)