What is hydrothermal gold deposits?
What is hydrothermal gold deposits?
Hydrothermal mineral deposits are accumulations of valuable minerals which formed from hot waters circulating in Earth’s crust through fractures. They eventually create rich-metallic fluids concentrated in a selected volume of rock, which become supersaturated and then precipitate ore minerals.
How are gold deposits formed?
Gold may occur as deposits called lodes, or veins, in fractured rock. It may also be dispersed within Earth’s crust. Most lode deposits form when heated fluids circulate through gold-bearing rocks, picking up gold and concentrating it in new locations in the crust.
How do epithermal gold deposits form?
These deposits were formed when hot molten rock associated with volcanoes provided a heat source to drive near-surface groundwater into kilometre scale convection systems in the Earth’s crust.
What determines where gold deposits exist?
The erosion process of water over time reveals the places in which large gold deposits can be found. Streams that cut through the rocks carry the smaller elements of gold down with them.
What are the 2 general types of hydrothermal deposits?
Two Types of Hydrothermal Deposits
- Conditions for Formation.
- Brine is Essential.
- Mesothermal Deposits.
- Epithermal Deposits.
Is gold a hydrothermal deposit?
Hydrothermal ore deposits that are exploited for gold include both gold-only deposits, such as orogenic deposits, and gold-bearing examples of the common hydrothermal deposit types that are formed around upper-crustal magmatic centres, in particular porphyry and epithermal deposits.
Where are epithermal deposits located?
These mineral deposits commonly occur in island, volcanic and continental arcs associated with subduction. However, they can also be found in shallow marine environments and in association with hot springs.
Where are hydrothermal deposits usually found?
TECTONICS | Hydrothermal Vents At Mid-Ocean Ridges Most hydrothermal deposits that have been found on intermediate- and slow-spreading ridge crests are focused along faults, fissures, and volcanic structures within large rift valleys that are several kilometres wide.
What are the conditions for the formation of hydrothermal deposits?
Conditions necessary for the formation of hydrothermal mineral deposits include (1) presence of hot water to dissolve and transport minerals, (2) presence of interconnected openings in the rock to allow the solutions to move, (3) availability of sites for the deposits, and (4) chemical reaction that will result in deposition.
How is gold transported in hydrothermal gold deposits?
Gold is mainly transported in solution as Au–Cl and Au–S complexes. The change of physicochemical conditions such as temperature, pressure, oxygen fugacity, and sulfur fugacity are effective mechanisms for gold precipitation. Gold tends to be concentrated in the vapor phase of fluids at high temperatures and pressures.
Which is an alternative title for hydrothermal ore deposit?
Alternative Title: hydrothermal ore deposit. Hydrothermal mineral deposit, any concentration of metallic minerals formed by the precipitation of solids from hot mineral-laden water (hydrothermal solution). The solutions are thought to arise in most cases from the action of deeply circulating water heated by magma.
How is hydrothermal alteration related to mineral exploration?
Hydrothermal alteration provides a significant guide to mineral exploration, as many deposits are characterized by wide alteration haloes and zonations, such as those observed in porphyry systems ( Fig. 1) and chlorite–sericite alterations in the basement of volcanogenic massive sulfide deposits.