What is a copper gold porphyry?
What is a copper gold porphyry?
Porphyry copper deposits contain up to 100 t of gold and are among the largest reservoirs of gold in the upper crust (Kerrich et al., 2000). They are commonly surrounded by deposits and country rock containing gold that is thought to have been derived from them (Jones, 1992).
What is porphyry system?
Porphyry systems are universally typified by three main features: (1) presence of veins and veinlets forming stockworks, within which are disseminated sulphides of Fe, Cu, Mo, Pb and Zn, as well as native Au, and minerals of W, Bi and Sn; (2) the mineralisation is spatially and genetically related to intrusive bodies.
What is a porphyry gold deposit?
Porphyry copper–gold deposits are large volume, low-grade disseminations formed by precipitation of copper and gold (plus molybdenum) from fluids of magmatic origin1.
What is the importance of porphyry?
Porphyry ore deposits are the Earth’s major resources of copper, molybdenum, and rhenium (Sillitoe, 2010) and also provide significant amounts of gold, silver, and other metals. Mineralization styles include stockwork veins, hydrothermal breccias, and wall-rock replacements.
Where are porphyry copper deposits found?
Large porphyry copper deposits are worked in the southwestern United States (where molybdenum is produced as a by-product), the Solomon Islands, Canada, Peru, Chile, Mexico, and other parts of the world.
Where can porphyry be found?
Porphyries are most commonly found along the west coast of North and South America, as well as in the Southwest Pacific. Porphyries are formed in tectonic plate convergent zones where oceanic crust has subducted beneath the continental crust, and in some cases the oceanic crust.
What causes porphyry?
Porphyritic rocks are a product of igneous differentiation, and are generally formed when a column of rising magma is cooled in two stages: In the first stage, the magma is cooled slowly deep in the crust, creating the large crystal grains, with a diameter of 2mm or more.
How is porphyry mined?
Porphyry copper deposits are typically mined by open-pit methods.
Is porphyry A rare stone?
Imperial Porphyry is arguably the rarest and most historically important stone in the world. It comes from only one source; a single mountain in Egypt that the Romans called Mons Porphyry.
What does porphyry look like?
The larger crystals are called phenocrysts. In its non-geologic, traditional use, the term porphyry refers to the purple-red form of this stone, valued for its appearance.
Where are porphyry deposits found?
Porphyry deposits are clustered in discrete mineral provinces, which implies that there is some form of geodynamic control or crustal influence affecting the location of porphyry formation. Porphyry deposits tend to occur in linear, orogen-parallel belts (such as the Andes in South America).
What is Boyongan and bayugo porphyry Cu-Au?
The Boyongan and Bayugo porphyry Cu-Au mineral deposits, discovered under postmineralization cover during the previous decade, are part of an emerging belt of intrusion-centered Au-rich Cu mineral deposits and prospects in the Surigao district of northeast Mindanao, Philippines.
What is the life cycle of Boyongan and bayugo?
Geologic and geochronological constraints on the life cycle of Boyongan and Bayugo describe an extremely dynamic history of emplacement, exhumation, weathering, and burial over a period of 2.3 m.y.
What is illite alteration at Boyongan?
At Boyongan and Bayugo, intense and pervasive illite alteration, in association with pyrite, chalcopyrite, and tetrahedrite-tennantite, developed in narrow structures crosscutting quartz-K-feldspar veins.