USING IGNEOUS GEOCHEMISTRY FOR INSIGHT INTO SURFACE WATER FLOW PATHS, BATTLESHIP BUTTE ALLUVIAL DEPOSITS, NEAR MOAPA, NV

Battleship Butte located east of the Arrow Canyon Range and south of the Meadow Valley Mountains, is comprised of two main alluvial deposit units, a lower unit with Paleozoic clasts and minor amounts (about 5 percent) of Tertiary volcanic clasts unconformably overlain by an upper unit with only Paleozoic clasts. Basin sedimentation in this area was contemporaneous with Cenozoic extension. Initial drainage in the White River and Meadow Valley Wash basins was internal, but both basins were later captured by the Colorado River system making them externally drained. Geochemical analyses of eleven volcanic clasts collected from the lower alluvium at Battleship Butte were used to determine the provenance of the volcanic clasts. The origin of the volcanic clasts provide insight into basin deposition and surface water flow paths that led to the formation of the lower alluvium at Battleship Butte. The Battleship Butte alluvial units are incised by the current Quaternary drainage system. The unconformity at the base and composition of the younger alluvial unit indicates a change of provenance from Tertiary volcanic and underlying Paleozoic sections in the Meadow Valley Mountains to the Paleozoic only rocks of Arrow Canyon Range to the east. Trace and rare-earth elements correlate volcanic clasts at Battleship Butte to Tuff of Etna from the Caliente Caldera Complex and the Gregerson Basin Member, part of the Kane Wash Tuff, from the Kane Springs Wash Caldera to the north of Battleship Butte. Overall analysis of alluvial units in Battleship Butte indicates the capture of the Meadow Valley Wash and White River Basins by the Colorado River system and/or a continued drop in base level of the Colorado River system.