Publications

Intense winter storms in the San Francisco Bay area (SFBA) of California, USA often trigger shallow landslides. Some of these landslides mobilize into potentially hazardous debris flows. A growing body of research indicates that rainfall intensity-duration thresholds are insufficient for accurate prediction of landslide occurrence. In response, we have begun long-term monitoring of the...

The article offers information on mercury, a mineral commodity used in industrial and small-scale gold mining applications. Mercury has been reported to be used for amalgamation with gold since the Roman times. Mercury from cinnabar from Almadén, Spain has been used by Romans and has been continued to be used through the Middle Ages and the Colonial era.

Domestic production, consumption, exports and prices of perlite in the United States were all estimated to have decreased in 2011 compared with 2010, but not significantly. The weak economic conditions that prevailed in the United States for most of the 2011 probably accounted for these decreases. The only statistic that increased was imports, which were estimated to have risen by about...

Garnet has been used as a gemstone since the Bronze Age. However, garnet's angular fractures, relatively high hardness and specific gravity, chemical inertness, and nontoxicity make it ideal for many industrial applications. It is also free of crystalline silica and can be recycled.

World fluorspar demand continued to show signs of recovery from 2008-2009 recession. In 2011, nearly all fluorspar (CaF2) consumed in the United States was imported. Hastie Mining and Trucking Co. produced some fluorspar as a byproduct from its limestone quarry operations in Illinois. In addition, a small amount of usable synthetic fluorspar was produced from industrial waste streams.

The United States is import-reliant for nearly all of the bauxite that it consumes. Small amounts of bauxite and bauxitic clays are produced in Alabama, Arkansas and Georgia for nonmetallurgical uses. Metallurgical-grade bauxite (crude dry) imports in 2011 totaled 9.54 Mt (10.5 million st), 18 percent more than the quantity imported in 2010. Jamaica (54 percent). Guinea (25 percent) and...

Neogene (Miocene–Pliocene) sedimentary rocks of the northeastern Sierra Nevada were deposited in small basins that formed in response to volcanic and tectonic activity along the eastern margin of the Sierra. These strata record an early phase (ca. 11–10 Ma) of extension and rapid sedimentation of boulder conglomerates and debrites deposited on alluvial fans, followed by fluvio-lacustrine

We present new evidence for the assignment of the Neoproterozoic Massabesic Gneiss Complex of New Hampshire to the Gander terrane rather than the Avalon terrane. The majority of Avalonian (sensu stricto) igneous and meta-igneous rocks as defined in Maritime Canada have positive whole-rock ɛNd compared to more negative values for Gander rocks, although there is a region of overlap in ɛNd...

Domestic production of industrial sand and gravel in 2011 was about 30 Mt (33 million st), increasing slightly compared with 2010. Some important end uses for industrial sand and gravel include abrasives, filtration, foundry, glassmaking, hydraulic fracturing sand (frac sand) and silicon metal applications.

Alaska’s known mineral endowment includes some of the largest and highest grade deposits of various metals, including gold, copper and zinc. Recently, Alaska has also been active in the worldwide search for sources of rare earth elements (REE) to replace exports now being limitedby China. Driven by limited supply of the rare earths, combined with their increasing use in new ‘green’...

In 2011, world potash production consumption and sales increased from those of 2010, exceeding levels recorded before the economic downturn in 2008-2009.

The estimated value of natural gemstones produced from U.S. deposits during 2011 was $10.6 million, a 6-percent increase from 2010. U.S. gemstone production included agate, amber, beryl, coral, garnet, jade, jasper, opal, pearl, quartz, sapphire, shell, topaz, tourmaline, turquoise and many other gem materials.