hydrothermal alteration

hydrothermal alteration

[‚hī·drə′thər·məl ‚ȯl·tə′rā·shən]
(geology)
Rock or mineral phase changes that are caused by the interaction of hydrothermal liquids and wall rock.
References in periodicals archive ?
The Mallard Duck Bay prospect is a zone of hydrothermal alteration covering an area greater than eight square km.
The target comprises well developed hydrothermal alteration coincident with anomalous surface geochemistry, particularly molybdenum, and an outcropping quartz-iron-oxide (oxidised sulphides) veinlet stockwork.
Most samples indicated widespread hydrothermal alteration consisting of argillic and potassic alteration and the formation of extensive quartz breccias.
Previous exploration programs on the property by Walker Lane Gold and Evolving Gold have identified the Buster zone, an east-west-trending zone of intense hydrothermal alteration that is 10,000 feet long and up to 1,000 feet wide.
At Gumushane, in eastern Turkey, areas of extensive hydrothermal alteration have been recognised in the project area, as well as
Resistivity is the geophysical technique of choice in the Athabasca Basin due to its ability to image hydrothermal alteration systems, which form resistivity "chimneys", often associated with fault zones and unconformity-type uranium deposits.
Other topics include hydrothermal alteration geochemistry of Egypt's Betam gold deposit, local economic development responses in selected South African gold and coal mining areas, and phytochelatins in the wild plants from Guanajuato City.
5 km2 of mid-Tertiary aged volcanic rocks having extensive areas of hydrothermal alteration.
The last ten years lithogeochemistry is playing an increasingly dominant role in many exploration programs for several reasons: 1) A better understanding of the major and trace element and isotopic characteristics of tectonic regimes containing certain deposit types, and an interest by petrologists in communicating these findings to the explorationist; 2) A refinement and proliferation of techniques used to identify geochemical gradients within hydrothermal alteration systems; 3) Increasing accuracy and cost effectiveness in analytical methods available to commercial laboratories; and 4) The availability of inexpensive, powerful hardware and software to allow the interrogation of lithogeochemical data and its incorporation in layered datasets.
Hydrothermal vents are a source to the ocean of alkali elements that leach from the crust during hydrothermal alteration (although this process may be tempered somewhat by lower-temperature weathering of the shallow crust away from the ridges, which removes alkali elements from seawater).
Surface exploration work and drilling conducted by Strongbow in May 2012 on a property five kilometres east of the North Pit encountered hydrothermal alteration with associated, locally anomalous, gold and molybdenum values within mafic to felsic volcanic rocks.
The target area is primarily underlain by strong hydrothermal alteration of a felsic tuff.