Hypogene
In ore deposit geology, hypogene processes occur deep below the earth's surface, and tend to form deposits of primary minerals, as opposed to supergene processes that occur at or near the surface, and tend to form secondary minerals.
At great depth the pressure is high, and water can remain liquid at temperatures well above 100 °C. Hot aqueous solutions originating in the magma contain metal and other ions derived from the magma itself, and also from leaching of surrounding rocks. Hypogene deposition processes include crystallization from the hot aqueous solutions rising through the earth's crust, driven by heat provided by the magma.
Major dissolved components are chlorine, sodium, calcium, magnesium and potassium, and other important components include iron, manganese, copper, zinc, lead, sulfur (as SO4 or S or both) carbon (as HCO3 and CO2) and nitrogen (as NH4). Most ore fluids contain chloride as the dominant anion.