GEOE Ore deposit chart

For porphyry deposits, what is the usual host rock type?

Felsic to intermediate porphyritic intrusions.

For porphyry deposits, what is the genetic process?

Magmatic-hydrothermal.

For porphyry deposits, what are the primary metals mined?

Cu, Mo, Au.

For porphyry deposits, what is the typical geological / tectonic setting?

Subduction arcs.

For porphyry deposits, what is the typical metal precipitation mechanism?

Cooling and fluid-rock reaction causes sulfides to precipitate in stockworks and veins.

For placer deposits, what is the usual host rock / host material type?

Alluvial sediments or river gravels.

For placer deposits, what is the genetic process?

Surficial sedimentary.

For placer deposits, what are common primary metals/minerals mined?

Au and diamonds.

For placer deposits, what is the typical geological / tectonic setting?

Rivers, streams, and beaches.

For placer deposits, what is the typical metal precipitation / concentration mechanism?

Dense minerals settle where water slows down.

For greenstone hosted Au deposits, what is the usual host rock type?

Metamorphosed volcanic and sedimentary rocks.

For greenstone hosted Au deposits, what is the genetic process?

Hydrothermal.

For greenstone hosted Au deposits, what are the primary metals mined?

Au.

For greenstone hosted Au deposits, what is the typical geological / tectonic setting?

Convergent orogenic belts with faults.

For greenstone hosted Au deposits, what is the typical metal precipitation mechanism?

Au-bearing fluids move through faults; pressure drop and fluid-rock reaction precipitate Au.

For Mississippi Valley Type deposits, what is the usual host rock type?

Carbonate rocks.

For Mississippi Valley Type deposits, what is the genetic process?

Hydrothermal.

For Mississippi Valley Type deposits, what are the primary metals mined?

Zn, Pb, Ag.

For Mississippi Valley Type deposits, what is the typical geological / tectonic setting?

Platform carbonate basins.

For Mississippi Valley Type deposits, what is the typical metal precipitation mechanism?

Salty brines mix or react with reduced sulfur and precipitate sphalerite and galena.

For gabbro-anorthosite intrusions, what is the usual host rock type?

Mafic intrusive rocks.

For gabbro-anorthosite intrusions, what is the genetic process?

Magmatic.

For gabbro-anorthosite intrusions, what are the primary metals mined?

Ni, Cu, PGE.

For gabbro-anorthosite intrusions, what is the typical geological / tectonic setting?

Mantle-derived mafic intrusions.

For gabbro-anorthosite intrusions, what is the typical metal precipitation mechanism?

Immiscible sulfide melt separates and settles.