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A variety of gold deposits are formed in accretionary orogens, including orogenic gold deposits. [38] Orogenic gold deposits are typically located in metamorphosed fore-arc and back-arc regions, as well as in the arc [3] and show a close spatial relationship to lamprophyres and associated felsic porphyry dikes and sills. [39]
High-grade gold ore from the Harvard Mine, Jamestown, California, a wide quartz-gold vein in California's Mother Lode. Specimen is 3.2 cm (1.3 in) wide. Various theories of ore genesis explain how the various types of mineral deposits form within Earth's crust. Ore-genesis theories vary depending on the mineral or commodity examined.
The ocean reservoir contains an estimated 5.6x10 9 Mg of gold and oceanic gold concentration is about 4 ng Au/L with higher values in some coastal waters. [1] Au(I/III)-ions and Au(0)-colloids are unstable under surface conditions in aqueous solutions and commonly form ligand complexes with substances excreted by microorganisms. [3]
Gold, a chemical element; Genomes OnLine Database; Global-scale Observations of the Limb and Disk, a NASA Explorer Mission of Opportunity; GOLD (parser), an open-source parser-generator of BNF-based grammars; Graduates of the Last Decade, an Institute of Electrical and Electronics Engineers program to garner more university level student members
Most minerals on Earth formed after photosynthesis by cyanobacteria (pictured) began adding oxygen to the atmosphere. Mineral evolution is a recent hypothesis that provides historical context to mineralogy. It postulates that mineralogy on planets and moons becomes increasingly complex as a result of changes in the physical, chemical and ...
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The invisible nature of the gold in the deposit makes it difficult to find deposits of that kind. The class of deposit was defined after the Carlin mine became a mass producer of gold in the 1960s and it was recognized that other deposits of that type should exist. [5] Most of the mines in the Great Basin in the United States belong to the ...
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