نتایج جستجو برای: epithermal gold
تعداد نتایج: 83832 فیلتر نتایج به سال:
the takmeh-dash region comprises a wide variety of igneous bodies that have been developed from early to late neogen. the granitic rocks and related aplite apophyses have been developed along fault-dominated structures which defines a well pronounced mineralized zone. according to isotopic and fluid inclusion studies, most of the quartz-pyrite units are solution-related with some traces of cu, ...
Gold production in New Zealand has been significant since the mid 1800s, totalling 900 t (29 Moz) to 2005. In addition, there is potential for a further 1230 t (39.5 Moz) of gold in known and undiscovered deposits. Most of the gold has originated from epithermal and mesothermal (orogenic) hydrothermal systems. Epithermal gold occurs in the Northland, Coromandel and Taupo volcanic zones in quart...
This report presents three new potassium-argon isotopic age determinations of minerals associated with epithermal alteration from the Toodoggone district, north-central British Columbia. The Toodoggone area has received extensive exploration attention over the past 10 years. In addition to a former goldsilver producer (Baker mine), the district contains a major new gold-silver mine in developme...
Unusual mineralized and silicified carbonate-rich geodes were found hosted in Lower Triassic red mudstones in Central Spain. From their borders to their centres, the geodes display (a) a millimetric carbonate crust, (b) a quartz rim, (c) massive dolomite, (d) gold-bearing iron-rich infills (hematite laths and goethite with up to 7000 ppm of gold) and (e) calcite cements that sometimes seal the ...
Introduction Epithermal deposits are usually found in association with near-surface magmatic-hydrothermal environments with volcanic rocks. According to studies, their formation depth is less than 1.5 km and the temperature for their formation is less than 300 ° C. Epithermal deposits are usually rich in gold to gold-silver and rich in silver and include low sulfide, medium sulfide and hig...
Surface geological and geochemical mapping have been key technical contributors to many gold discoveries over the past 25 years. However, in the last ten years there has been a growing emphasis on using geophysical techniques to compliment them in covered terrains. As the search for gold deposits under covered areas expands, there will be increasing emphasis on integrating the geoscientific dis...
The variety of lithologies from Late Precambrian to Quaternary and suitable conditions for mineralization caused formation of Zarshuran gold and arsenic deposit in black schists, shale, limestone and dolomite. The ore paragenesis include As, Sb, Fe, Pb, Zn, Hg sulfides and gold along with fluorite, barite and quartz. The most important alteration is silicification which is more obvious in the o...
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