GROUND WATER IN THE OAK SPRING FORMATION AND HYDROLOGIC EFFECTS OF UNDERGROUND NUCLEAR EXPLOSIONS AT THE NEVADA TEST SITE

摘要

Tuff, welded tuff, and tuffaceous sandstone of the Oak Spring;formation of Tertiary age overlie unconformably diverse types of Paleozoic rocks. Beneath the major basins of the Test Site the main zone of saturation is in alluvial fill or the Oak Spring, which is an aquifer of moderate to low permeability. Hydraulic gradients are low.nSeveral zones of perched ground water have been defined in tuff of the Oak Spring formation near the explosion sites. The Rainier test took place in a unit stratigraphically above a thin, probably discontinuous zone of perched water. The tunnel system for the Logan and Blanca experiments encountered ground water and acted as a drain until the Logan explosion, when flow ceased.