Geology

Geology of the Black Rock Desert area

Links

• Nevada Bureau of Mines and Geology
  The Nevada Bureau of Mines and Geology (NBMG) is a research and public service unit of the University of Nevada and is the state geological survey. NBMG scientists conduct research and publish reports on mineral resources, engineering geology, environmental geology, hydrogeology, and geologic mapping. Current activities in geologic mapping and mineral resources include detailed geologic mapping and stratigraphic studies in Nevada, comparative studies of bulk-mineable precious-metal deposits, geochemical investigations of mining districts, metallic and industrial mineral resource assessments, igneous petrologic studies, hydrothermal experiments, and research on the origin of mineral deposits.

• The Tufas of Pyramid Lake, Nevada Abstract Pyramid Lake is the site of some of the Earth's most spectacular tufa deposits. The Tufas are composed of calcium carbonate (CaCO₃). The large tufa mounds, reef- and sheet-like tufas formed within Pyramid Lake, between 26,000 and 13,000 years (yr) ago, when the lake was part of pluvial Lake Lahontan. The mounds are composed of large interlocking spheres that contain multiple generations of a crystalline (thinolite) variety of tufa. Over time many of the mounds have fallen apart, exposing an internal network of tubes. The tubular structures are thought to have been created when springs discharged from the bottom of Pyramid Lake, supplying calcium that combined with carbonate dissolved in lake water to form the mounds. The reef- and sheet-like deposits contain pillow and pendant forms made up of a branching variety of tufa that often grades into dense layers or nodules. Dense layers of tufa also coat cobbles and boulders that were deposited in near-shore shallow-water areas. The thickest tufa deposits formed at lake-bottom sites of ground-water discharge and at overflow elevations¹ where the lake was held at near-constant levels for long periods of time.

• IDENTIFICATION OF A DISTINCT TERRANE IN THE CORDILLERA THAT IS OFFSET ALONG THE EARLY CRETACEOUS DEXTRAL MSNI FAULT SYSTEM
  Mapping along the Nevada-southeast Oregon portion of the MSNI fault (this portion previously called the western Nevada shear zone; Wyld and Wright, 2001) has identified several lithotectonic assemblages that are clearly out of place with respect to geologic provinces to the east. These include (in Oregon) the Middle Jurassic continental arc assemblage of the Pueblo Mountains, and (in Nevada) Permian volcanogenic rocks at Black Rock Point, Permian and early Mesozoic carbonate, clastics and bimodal volcanogenic rocks in the Granite Range, and an assemblage of argillite, quartzite and carbonate in the Fox Range that is at least in part Late Triassic or younger. Quartzites from the Fox and Granite Ranges have a detrital zircon age signature identical to that of Jurassic erg sandstones of the Colorado plateau.

• USGS Multielement Geochemical Dataset of Surficial Materials for the Northern Great Basin