Publications

We used geological field studies and diatom biostratigraphy to test a published hypothesis that Neogene marine siliceous strata in the Maricopa and Parkfield areas, located on opposite sides of the San Andreas Fault, were formerly contiguous and then were displaced by about 80–130 kilometers (km) of right-lateral slip along the fault. In the Maricopa area on the northeast side of the San...

The U.S. Geological Survey (USGS) recently assessed the potential for undiscovered oil and gas resources of the Laptev Sea Shelf Province as part of the 2008 Circum-Arctic Resource Appraisal (CARA) program. The province is situated in the Russian Federation and is located between the Taimyr Peninsula and the Novosibirsk (New Siberian) Islands. Three assessment units (AUs) were defined...

The U.S. Geological Survey estimates a mean of 40 million pounds of in-place uranium oxide (U3O8) remaining as potential undiscovered resources in the Southern High Plains region of Texas, New Mexico, and Oklahoma. This estimate used a geology-based assessment method specific to calcrete uranium deposits.

Tin (Sn) is one of the first metals to be used by humans. Almost without exception, tin is used as an alloy. Because of its hardening effect on copper, tin was used in bronze implements as early as 3500 B.C. The major uses of tin today are for cans and containers, construction materials, transportation materials, and solder. The predominant ore mineral of tin, by far, is cassiterite...

Fluorine compounds are essential in numerous chemical and manufacturing processes. Fluorspar is the commercial name for fluorite (isometric CaF2), which is the only fluorine mineral that is mined on a large scale. Fluorspar is used directly as a fluxing material and as an additive in different manufacturing processes. It is the source of fluorine in the production of hydrogen fluoride or

The platinum-group elements (PGEs)—platinum, palladium, rhodium, ruthenium, iridium, and osmium—are metals that have similar physical and chemical properties and tend to occur together in nature. PGEs are indispensable to many industrial applications but are mined in only a few places. The availability and accessibility of PGEs could be disrupted by economic, environmental, political...

Rhenium is one of the rarest elements in Earth’s continental crust; its estimated average crustal abundance is less than 1 part per billion. Rhenium is a metal that has an extremely high melting point and a heat-stable crystalline structure. More than 80 percent of the rhenium consumed in the world is used in high-temperature superalloys, especially those used to make turbine blades for...

Solid organic matter (OM) plays an essential role in the generation, migration, storage, and production of hydrocarbons from economically important shale rock formations. Electron microscopy images have documented spatial heterogeneity in the porosity of OM at nanoscale, and bulk spectroscopy measurements have documented large variation in the chemical composition of OM during petroleum...

Multiply isotopically substituted molecules (‘clumped’ isotopologues) can be used as geothermometers because their proportions at isotopic equilibrium relative to a random distribution of isotopes amongst all isotopologues are functions of temperature. This has allowed measurements of clumped-isotope abundances to be used to constrain formation temperatures of several natural materials...

The Colorado River in the southwestern U.S. provides an excellent natural laboratory for studying the origins of a continent-scale river system, because deposits that formed prior to and during river initiation are well exposed in the lower river valley and nearby basinal sink. This paper presents a synthesis of regional stratigraphy, sedimentology, and micropaleontology from the...

Adakitic intrusions are supposed to have a close genetic and spatial relationship to porphyry Cu deposits. However, the genesis of adakitic intrusions is still under dispute. Here, we describe newly discovered intrusive complex rocks, which are composed of ore-bearing, layered magnetite-bearing gabbroic and adakitic rocks in Jiamate, East Junggar, NW China. These Jiamate Complex...

No abstract available.