GEOLOGICAL HISTORY OF YUCCA MOUNTAIN (NEVADA) AND THE PROBLEM OF A HIGH-LEVEL NUCLEAR WASTE REPOSITORY

摘要

Three types of deposits are widely distributed throughout the Yucca Mountain un-saturated zone: mosaic breccias, quartz-calcite veinlets, and micritic opal-calcite veins and associated slope deposits were found to be of hydrothermal origin. The inference is based on petrographic, accessory mineral, fluid inclusion, and stable isotopic data. The overall conclusion is that recurrent low-temperature hydrothermal (epithermal) activity occurred at Yucca Mountain in the geologically recent past (from ca. 8-10 Ma to as recently as 25 ka). New data require the currently-accepted concept of the hydrogeological system at Yucca Mountain to be reconsidered. The subject relates to the suitability of Yucca Mountain as a high-level nuclear waste site.