1. Sub-crop geologic map of pre-Tertiary rocks in the Yucca Flat and northern Frenchman Flat areas, Nevada Test Site, southern Nevada [microform] Yale Public content 1997. 2002-06-01T04:00:00Z. 2015-07-06T16:50:41Z. Geological Survey (U.S.). The Survey. English. Public. Nevada and Nevada Test Site.