1. المحاليل الحرمائيه ورواسبها Hydrothermal Solutions and their Mineral Deposits
الخامات والرواسب المعدنيه الحرمائيه هى تلك الرواسب التى تتكون بواسطه محاليل مائيه ممعدنه وفى درجات حراره مختلفه.
تضم هذه الرواسب مجموعه كبيره ومتنوعه لمعظم العناصر، ومن أمثله هذه الخامات:
رواسب الكبريتيدات البركانيه الكتليه Volcanogenic Massive Sulfide (VMS) Deposits
الرواسب العرقيه Vein Deposits
رواسب النحاس البورفيرى Porphyry Copper Deposits
رواسب السكارن Skarn Deposits

2. Origins of the Solutions
Magmatic Sources
Meteoric water (ground water) sources
Seawater sources
Regional Metamorphism !

3. hydrothermal
system

4. Composition of the Solutions
The principle ingredient of hydrothermal solutions is a brine – hot water
Containing dissolved salts such as NaCl, KCl, CaSO4 and CaCl2
The range in salinity varies from that of seawater to about ten times the salinity of seawater
Capable of dissolving small amounts of elements such as Au, Ag, Cu, Pb and Zn
High temperatures increase the effectiveness of the brines to dissolve metals

5. Causes of Mineral Precipitation
a convection cell is required to maintain a constant precipitation
Rapid movement of the fluid into porous layers (open fractures such as veins and brecciated rocks)
Sudden cooling of the fluids leads to rapid precipitation of minerals over a limited region
Boiling, rapid pressure decrease, reactions with adjacent rock types, and mixing with seawater can also cause rapid precipitation and the concentration of mineral deposits.