Cuttings from geothermal wells in Dixie Valley, Nevada document the complex history of the Jurassic reservoir rocks now contained within the hanging wall of the Stillwater normal fault. Six stages of postOligocene alteration can be recognized on the basis of mineral paragenesis, rock associations, fluid-inclusion temperatures and apparent salinities. The paragenetic sequence from oldest to youn...

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...

Tourmaline-bearing quartz veins and replacement deposits, commonly copperand gold-bearing, are found in unusual concentration in northwestern Nevada and adjacent northeastern California in Triassic and Jurassic arc rocks and in the Cretaceous plutons that intrude them. Mines and prospects that exploit the tourmaline-bearing deposits are found in a zone approximately 70 miles long and 50 miles w...

In the Santander Massif of Eastern Cordillera Colombia, intense Pliocene to Holocene sulfide-rich gold mineralization occurs in a six kilometers long section La Baja fault zone, where it crosses partially migmatized gneisses and intrusions Triassic-Cretaceous quartz monzonites granites. These intrusives are mineralogically texturally similar neosome migmatites that they intrude. The as medium l...

The research at Mendoke Mountains, Southeast Sulawesi Province, particularly for the study of gold deposits, becomes a new challenge because there is no previous detailed study. This aims to analyze characteristics orogenic which include type and texture quartz veins, alteration hydrothermal mineralization with hosted metamorphic rocks. methods used fieldwork laboratory analysis. veins were ide...

Abstract The Kawatuna area has a complex geological structure condition and is estimated to be weak zone for hydrothermal solutions rise then accumulate into deposits in the form of veins. Based on this, it makes this interesting study. This study aims determine its influence distribution veins area. method used surface mapping structures analysis. mapping, was found that composed schist rock u...

Archean Quartzose Rocks at Akilia, Greenland Fedo and Whitehouse (1) presented data to support their hypothesis that granulite grade quartz magnetite rocks on the island of Akilia, southwest Greenland—which are conformably interposed with pyroxenite and hornblendite units that date from before 3830 million years ago (Ma) (2–4)—had a metasomatic ultramafic igneous origin. They offered that inter...