Publications

No abstract available.

For the last several years, Montana has been the leading talc producing state in the United States (U.S. Geological Survey, 1996). For example, in 1992 Montana supplied about 40 percent of the U.S. mine production of talc (Virta, 1992). All of this production has come from the large deposits of high purity talc in the southwestern part of the state. All Montana talc is currently (1997) extracted f

Garnet crystals, some of gem quality, have been sought by rock hounds for many years in the alluvial deposits of the Alder Gulch-Ruby River area. Since 1995, garnet have been extracted from these gravels for industrial products at two separately own placer mines in the region: (1) at Cominco American's "Ruby Garnet" operation at Alder , Montana and (2) at the "Sweetwater Garnet" operation in the S

No abstract available.

No abstract available.

Travelers on Interstate Highway 81 can see remnants of the Ice Age on the mountains between Strasburg and Harrisonburg, Virginia. Scattered along the miles of green, forested mountains are many gray patches without any forests. These treeless patches, or openings, in the steep mountain forests are block fields - geologic features that owe their origin to the Ice Age.

Balkan endemic nephropathy (BEN) has attracted increasing attention as a possible environmental disease, and a significant amount of research from complementary scientific fields has been dedicated to its etiology. There are two actual competing theories attempting to explain the cause of this kidney disease: 1) the mycotoxin hypothesis, which considers that BEN is produced by ochratoxin A ingeste

Mode-of-occurrence data are summarized for 13 potentially hazardous elements (Be, Cr, Mn, Co, Ni, As, Se, Cd, Sb, Hg, Pb, Th, U) in coal. Recent work has refined mode-of-occurrence data for Ni, Cr, and As, as compared to previous summaries. For Cr, dominant modes of occurrence include the clay mineral iliite, an amorphous CrO(OH) phase, and Cr-bearing spinels. Nickel is present in Fe-sulfides (pyr

We previously reported indirect but compelling evidence that fine-grained H2O ice under elevated CH4 gas pressure can persist to temperatures well above its ordinary melting point while slowly reacting to form methane clathrate hydrate. This phenomenon has now been visually verified by duplicating these experiments in an optical cell while observing the very slow hydrate-forming process as the rea

A long sequence of fossil palynomorph assemblages from a 323-m-long core taken at Owens Lake has enabled us to evaluate the gross vegetational trends for the Owens Valley region of California over the past ~800,000 years. Shifts in vegetation composition and abundance in the study area during the Pleistocene were indicated in core sediments by marked fluctuations in the pollen frequencies of pines

No abstract available.

Detailed fluid inclusion studies on coarse-grained sphalerite from the OH vein, Creede, Colorado, have shown that the abrupt color changes between growth zones correspond to abrupt changes in the nature of the ore fluids. Within each growth zone, however, the composition of the fluids remained constant. The base of a distinctive orange-brown growth zone marks a sharp increase in both temperature a