Search results
Results from the WOW.Com Content Network
An orogenic gold deposit is a type of hydrothermal mineral deposit. More than 75% of the gold recovered by humans through history belongs to the class of orogenic gold deposits. [ 1 ] Rock structure is the primary control of orogenic gold mineralization at all scales, as it controls both the transport and deposition processes of the mineralized ...
Ore genesis. 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.
Orogeny (/ ɒˈrɒdʒəni /) is a mountain - building process that takes place at a convergent plate margin when plate motion compresses the margin. An orogenic belt or orogen develops as the compressed plate crumples and is uplifted to form one or more mountain ranges.
The Laramide orogeny was caused by subduction of a plate at a shallow angle. The orogeny is commonly attributed to events off the west coast of North America, where the Kula and Farallon Plates were sliding under the North American plate. Most hypotheses propose that oceanic crust was undergoing flat-slab subduction, that is, subduction at a ...
Classification. Iron oxide copper gold (IOCG) deposits are considered to be metasomatic expressions of large crustal-scale alteration events driven by intrusive activity. The deposit type was first recognised by discovery and study of the supergiant Olympic Dam copper-gold-uranium deposit (Olympic Dam mine), and South American examples.
The Taconic orogeny was a mountain building period that ended 440 million years ago (Ma) and affected most of modern-day New England. A great mountain chain formed from eastern Canada down through what is now the Piedmont of the east coast of the United States. As the mountain chain eroded in the Silurian and Devonian periods, sediment spread ...
Mauritanide Orogeny – Ancient orogen parallel to the west coast of Africa from Morocco to Guinea-Bissau. Mozambique Orogeny – Band in the Earth's crust from East Antarctica through East Africa up to the Arabian-Nubian Shield. Zambezian Orogeny – Area of mountain building now in southern Zambia and northern Zimbabwe.
The Sevier Fold and Thrust Belt extends from southern California near the Mexican border to Canada. [1] Basin and Range faults cut the older Sevier thrust faults. [4] The Sevier orogeny was preceded by several other mountain-building events including the Nevadan orogeny, the Sonoman orogeny, and the Antler orogeny, and partially overlapped in time and space with the Laramide orogeny.