Geology of the Marble exploration hole 4, Nevada Test Site, Nye County, Nevada
The Marble exploration hole 4 was drilled to determine the chemical and physical properties of marble from the surface to depth of about 1,200 feet. The drill hole is in the north-central part of the Tippipah Spring quadrangle, approximately 40 miles north of Mercury, Nev. The collar of the hole is at an elevation of 5,490.28 feet and has the Nevada State grid coordinates of N. 904,480.13 and E. 637,758.38. The hole is accessible by a graded dirt road easily traversed by heavy construction equipment, that connects to the highway between Mercury and Groom Lake. The hole was core drilled by Minerals Engineering Company, Grand Junction, Colo., with a 2,000-foot capacity Portadrill drilling rig and conventional NX coring equipment. Drilling was started July 13, and completed August 30, 1959. The drilling fluid was water for most of the hole. At some places in the hole, where loss of drilling fluid was high, the water was thickened with bentonitic mud. At 1,103 feet, presumed caving of the hole caused the drill stem to stick so that it could not be withdrawn; subsequently about 920 feet of the drill stem was recovered. The hole was then reamed to 800 feet and cemented from 785 to 855 feet. A whipstock was emplaced at depth of 805 feet so that the hole, which was vertical to this depth, would be deflected 4° from the vertical. Core was recovered for this part of the hole from 1,088 to 1,187 feet, the total depth. Seven feet of 8-inch outside diameter casing was set from the collar. This report summarizes the information obtained during preparation of the lithologic log of the core and presents results of chemical analyses of marble samples collected from surface near the drill hole. The report was prepared by the U.S. Geological Survey on behalf of the Albuquerque Operations Office, U.S. Atomic Energy Commission. The writers acknowledge the assistance of Mr. John Foster, drilling foreman for Minerals Engineering Company and Mr. Walter A. Johnson, field engineer for Holmes and Narver, Inc., the engineering-contracting firm.