Geophysical Data on the Climax Stock, Nevada Test Site, Nye County, Nevada

Abstract

A granitic stock at Oak Spring, Nevada, was selected in 1960 by the Atomic Energy Commission as a possible site to study the seismic effect of a deep nuclear shot contained in a large volume of rock. Geophysical surveys were conducted to determine the general configuration of the stock, particularly the thickness. The stock intrudes a sequence of carbonate and siliceous sedimentary rocks of Paleozoic age, which are overlain by Tertiary pyroclastic rocks consisting of tuff, welded tuff, and breccia. A three‐dimensional analysis of a detailed aeromagnetic survey indicates that the stock has a shape similar to a truncated cone, the diameter of which increases from about one mile at the surface to at least 6 miles near sea level, 5,000 feet beneath the surface. The stock, therefore, is much larger than indicated by the area of [Formula: see text] square miles exposed at the surface. In addition, computations show that the intrusion has a thickness of at least 13,000 ft. Much of the ambiguity of interpretation was removed from the analysis because susceptibility measurements of cores from recent drilling and remanent magnetization data from surface samples were available. Interpretation of a gravity profile over the stock gives the probable thickness of the overlying alluvial fill and buried tuff, but does not delineate the intrusive from the Paleozoic rocks.

Geologic interpretation of an aeromagnetic survey of the Iron Springs district, Utah

“…Various attempts to determine the depth extent of an intrusive body from aeromagnetic data have been reported; for examples, see Zietz ( 1960) and Allingham and Zietz (1962). The magnetic method, even when used in conjunction with other methods, is subject to severe limitations.…”

Geohydrology of the climax stock granite and surrounding rock formations, NTS

“…8), and intrudes a sequence of sedimentary rocks of Paleozoic age (mainly limestone, dolomite, and shale). This sedimentary sequence is overlain by Tertiary pyroclastic rocks of the Oak Spring Formation, consisting of tuff, welded tuff and breccia(Allingham and Zietz, 1961). The detailed outcrop pattern and adjacent rock types are shown inFig.…”

Offset of Tertiary arcs on the Alaska Peninsula: A section in <i>Geological Survey research, fiscal year 1981</i>

“…Geomagnetic methods of geophysical prospecting have been adapted in the Climax stock and Yucca fault areas of the Nevada Test Site for application in nearby areas that are presently under study as possible sites for storage of radioactive waste. Geophysical models of the Climax stock intrusive were previously reported by Allingham andZietz (1962) andWhitehill (1973). New interpretations by G. D. Bath, C. E. Jahren, J. G. Rosenbaum (USGS), and M. J.…”