the gandy gold-base metal deposit is located in tertiary torud-chahshirin volcano-plutonic range, north of central iran. various styles of gold mineralization occur throughout the range. mineralization at gandy occurs in close spatial relation with rhyolitic domes in a caldera setting in a series of narrow brecciated veins. two mineralogically and spatially different argillic alterations have a...

Hydrothermal venting at the Lucky Strike hydrothermal field, located on Mid-Atlantic Ridge, is associated with faulting linked to tectonic dismemberment of a central axial volcano. Radium-226/Ba dating barite indicates that least 6,600 years old, and one youngest known vent fields which typically have ages exceeding 20 ka. Deposit volume calculations indicate total accumulated mass deposits sea...

The Red Dog Zn-Pb deposits are hosted in organic-rich mudstone and shale of the Mississippian Kuna Formation. A complex mineralization history is defined by four sphalerite types or stages: (1) early brown sphalerite, (2) yellow-brown sphalerite, (3) red-brown sphalerite, and (4) late tan sphalerite. Stages 2 and 3 constitute the main ore-forming event and are volumetrically the most important....

On April 26, 1996, Public Law 104-134 was Chart 1 .-Payment volume, by type of disbursement, fiscal year 1997 enacted, requiring all Federal payments except tax refunds be issued electronically by January 2, 1999, thus beginning a new era in electronic N Federal tax 10.5% funds transfer (EFT). This legislation, the Debt Collection Improvement Act of 1996-part of the Omnibus Consolidated Resciss...

Control over the crystallography, morphology and hierarchical assembly of crystals are important goals in advanced materials engineering with important application potential. Most studies hitherto have concentrated on using different templates for the controlled nucleation and growth of ceramic crystals. In this paper, we demonstrate the crystallization of barium sulfate within thermally evapor...

Microbial processes played a major role in mineral precipitation throughout the Earth’s history. Such processes have been widely discussed for the last few decades with regard to carbonate precipitation. Other than microbial precipitation of carbonates, in natural environments is also of great interest the potential role of microbes in the precipitation of marine barite. Regarding carbonates, o...

Barite plaster has been largely used as shielding material in installations housing gamma radiation sources as well as x-ray generating equipment, in order to minimize exposure to individuals. However, some physical characteristics, such as density, plasticity, resistance to compression and radiation attenuation for the different types of barite plaster commercially available in Brazil are not ...