Hydrostratigraphic units within the alluvium and tertiary volcanics of East Central Yucca Flat, Nevada Test Site

Craig Thomas Shirley, University of Nevada, Las Vegas

Abstract

Lithologic and geophysical log data from 46 boreholes in East Central Yucca Flat, Nevada Test Site, are used to develop lithostratigraphic and hydrostratigraphic columns. Non-zeolitized volcanic lithostratigraphic units geologically correlate to hydrostratigraphic units. Zeolitized volcanic lithostratigraphic units are combined into a single hydrostratigraphic unit. No systematic trend of porosity or permeability was found in the alluvium which comprises the uppermost hydrostratigraphic unit. Profiles of mean porosity vs lithostratigraphic elevation for 11 lithostratigraphic units are presented. Nuclear test cavities, rubble chimneys and collapse craters collectively comprise a fourth hydrostratigraphic unit.