Hydrothermal Mineral Deposits

It is possible that more mineral deposits have been produced by deposition from hydrothermal solutions than any other procedures. Due to this a lot of research has consequently been placed on understanding the types of fluids that create the deposits and where they are expected to form. Mineralization takes place deep under the ground where it cannot be seen. By the time the deposit is open to the elements through the agents of uplift and erosion, the hydrothermal solutions that moved the metals are not there anymore. Nevertheless, a lot of details of the development of deposition are now understood, even though a good deal investigation still needs to be done.

Composition of the Hydrothermal Solutions
The main ingredient of hydrothermal solutions consists of water. Pure water, however, obviously does not have the ability of dissolving metals. Hydrothermal solutions are always brines, and they have dissolved salts for instance NaCl, KCl, CaSO₄ and CaCl₂. The amount of salinity differs from that of seawater, which is close to 3.5 wt percent to around ten times the salinity of seawater. These brines have the capacity of dissolving little quantities of elements for example; Au, Ag, Cu, Pb and Zn. High temperatures add to the efficiency of the brines and assist in dissolving the metals.

Origins of the Solutions
The waters of hydrothermal solutions can be obtained from magmatic sources, meteoric sources as well as from seawater. There are hydrothermal solutions that might also be produced due to regional metamorphism.

For the period of wet unfinished melting, the water that causes the melting to take place is set free when the magma hardens. This water then transports along with it soluble components such as NaCl, as well as elements for example Au, Ag, Cu, Pb, Zn, Hg, and Mo that do not easily go inside the ordinary minerals by ionic substitution.

Meteoric and seawater can in addition form hydrothermal solutions if they are heated in the right way and a convection system is produced. The basis of this high temperature is magmatic intrusions, so magma is an important ingredient in the production of hydrothermal mineral deposits. Hydrothermal mineral deposits are as a result related to convergent and divergent plate margins.