We present an oxygen isotope and petrologic study of four voluminous, zoned ash-flow
sheets of the Southwestern Nevada Volcanic Field (SWNVF): Topopah Spring (TS,> 1200 …

Field and microstructural analyses of faults with millimeters to hundreds of meters of
displacement within welded tuffs at Yucca Mountain, Nevada, has led us to identify four …

Uranium, Th and Pb isotopes were analyzed in layers of opal and chalcedony from
individual mm-to cm-thick calcite and silica coatings at Yucca Mountain, Nevada, USA, a site …

This paper summarizes various hazards identified between 1978 when Yucca Mountain,
located in arid southern Nevada, was first proposed as a potential site and 2008 when the …

Two novel methods of in situ isotope analysis, ion microprobe and microdigestion, were
used for 230Th/U and 234U/238U dating of finely laminated opal hemispheres formed in …

Calcite and silica form coatings on fracture footwalls and cavity floors in the welded tuffs at
Yucca Mountain, the potential site of a high-level radioactive waste repository. These …

The origin of secondary calcite–silica minerals in primary and secondary porosity of the host
Miocene tuffs at Yucca Mountain has been hotly debated during the last decade. Proponents …

This study focuses on rare earth element (REE) geochemistry of low-temperature calcite
coatings occurring on the walls of fractures throughout the upper kilometer of crystalline …

Extreme U and Pb isotope variations produced by disequilibrium in decay chains of 238U
and 232Th are found in calcite, opal/chalcedony, and Mn-oxides occurring as secondary …

Surface, unsaturated-zone, and saturated-zone hydrologic conditions at Yucca Mountain
responded to past climate variations and are at least partly preserved by sediment, fossil …