Gravity anomalies in the central Sierra Nevada, California

摘要: More than 1000 measurements of gravity in the central Sierra Nevada and adjacent regions to east show a decrease regional Bouguer values from −75 mgal at western edge mountains minimum about −235 just west crest, distance only 100 km. Farther east, positive gradient 0.6 mgal/km continues into Inyo-White Mountains for least 60 Local lows are associated with Cenozoic sediments Owens Valley, Long Mono Basin thick, narrow deposit Pleistocene Yosemite Valley. highs roof pendants meta volcanic rocks which extend down batholith depths more 2 The variation 160 can be explained by thickening earth's crust 35 52 km beneath Nevada, combined an eastward density 2.76 2.64 g/cm3. Gravity data support Romney's conclusion, based on seismic evidence, that local mountain root exists under southern parts not lower northern part, general accordance isostasy.