Abstract: "Drill hole UCe-18 was successfully logged with the U.S. Geological Survey-La Coste Romberg borehole gravity meter to a depth of 6,488 feet. That density increases with depth is apparent in both the alluvium and volcanic rock. The in situ density of the alluvium measured by the gravity meter ranges from 1.77 to 2.34 gm/cc; the lake beds beneath the alluvium have a density of 2.22 gm/cc; and the rhyolitic rocks range in density from 2.26 to 2.47 gm/cc. The average density determined from the borehole gravity meter data for the alluvium plus the lake beds is 2.22 gm/cc and for the volcanic rocks is 2.35 gm/cc."

The following report summarizes the geophysical studies of the rocks made in the U12e.10 tunnel of the Nevada Test Site.

Abstract: "Fifteen in situ interval densities were calculated from the borehole gravity meter observations made in Test Well-B. The weighted average density for all the rocks sampled by the gravity meter is 1.83 gm/cc. The alluvium density ranges from 1.71 to 1.82 gm/cc and averages 1.76 gm/cc. The lake beds range from 1.91 to 1.93 gm/cc and average 1.92 gm/cc. The Rainier Mesa Member averages 1.83 gm/cc. The Tiva Canyon Member averages 1.74 gm/cc and the upper 110 feet of Topopah Spring Member has a density of 2.30 gm/cc."