FRENCH, DON E., Independent Geologist, Billings, MT

ABSTRACT: Debris Slides of the Railroad Valley Area, Nye County, Nevada: Yet Another Interpretation of Grant Canyon and Bacon Flat Fields

Debris slides or slide blocks have been recognized as a stratigraphic element of Miocene-Pliocene valley fill deposits of the Railroad Valley area, east-central Nevada. Surface exposures are in Horse Camp basin, adjacent to the northeast of Railroad Valley, and along Little Meadow Creek, on the southeast side of the valley. Other debris slides have been penetrated by boreholes in the vicinity of Eagle Springs and Kate Spring fields, in the east-central part of Railroad Valley. This indicates that emplacement of debris slides was commonplace during the early development of the Railroad Valley basin. The geologic setting and evidence from paleogeologic mapping, dipmeter data, and correlation of resistivity-log markers in valley fill support a debris slide interpretation for Bacon Flat a d Grant Canyon fields, located a few miles south of Kate Spring. The geologic history inferred for these fields is (1) volcanic rocks were deposited on upper Paleozoic and lower Tertiary strata; (2) early Basin-Range faulting resulted in initial deposition of valley fill; (3) a debris slide comprised of Devonian rocks was emplaced and distribution modified by subsequent erosion; (4) late Basin-Range faulting overprinted the debris slide and resulted in deposition of remaining valley fill. Bacon Flat and Grant Canyon may be included with Kate Spring field as producing from debris slides of Paleozoic rock incorporated in valley fill. A working hypothesis that includes debris slides will aid the interpretation of ambiguous well and seismic data in the Railroad Valley area and other basins i the region.

AAPG Search and Discovery Article #90993©1993 AAPG Rocky Mountain Section Meeting, Salt Lake City, Utah, September 12-15, 1993.