Why are so many explorers chasing a porphyry payday?
Why are so many explorers chasing a porphyry payday?
Porphyries are often perceived as ‘capital intensive projects’ due to the billions of dollars required to get them up and running, Garwin says. Exploration is expensive, often requiring numerous deep, very expensive drill holes into ‘blind’ exploration targets hidden under cover or at great depths.
What is porphyry mining?
Porphyry copper deposits are copper ore bodies that are formed from hydrothermal fluids that originate from a voluminous magma chamber several kilometers below the deposit itself. Some mines exploit porphyry deposits that contain sufficient gold or molybdenum, but little or no copper.
Where are porphyry copper deposits found?
Porphyry copper deposits form in continental magmatic arcs along convergent plate-margin boundaries or in island-arc environments. The deposits are associated with subduction-related volcanic centers, although in some examples, they are thought to be associated with postcollisional volcanism.
How was porphyry formed?
The porphyry deposits are formed by differentiation and cooling of a column of rising magma in stages. The different stages of cooling create porphyritic textures in intrusive as well as in subvolcanic rocks.
What causes porphyry?
Porphyritic rocks are formed when a column of rising magma is cooled in two stages. In the final stage, the magma is cooled rapidly at relatively shallow depth or as it erupts from a volcano, creating small grains that are usually invisible to the unaided eye typically referred to as the ground mass.
Where is porphyry 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 is porphyry gold?
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 porphyry used for?
Porphyry is prized for its great compressive strength and exceptional durability. For this reason it is now most commonly used as a paving stone.
Is porphyry A rare stone?
Porphyries are reasonably common, but the rock from which this sculpture was carved, Imperial Red Porphyry, is rare, valuable and has historic significance. The stone came from the quarry of Mons Porpyritis (Egypt), the only source of Imperial Red Porphyry in the world. Romans valued the stone for carvings.
How much does porphyry cost?
Walking, biking and driving on porphyry driveways is easy and smooth. Because it is a unique material, porphyry can cost $15 or more per square foot.
What is the history of porphyry mining?
The first mining of low-grade copper porphyry deposits from large open pits coincided roughly with the introduction of steam shovels, the construction of railroads, and a surge in market demand near the start of the 20th century. Some mines exploit porphyry deposits that contain sufficient gold or molybdenum, but little or no copper.
What are porphyry deposits and why are they important?
Porphyry deposits represent an important resource of copper; however, they are also important sources of gold and molybdenum – with porphyry deposits being the dominant source of the latter.
What is the age of porphyry and epithermal gold?
For both porphyry and epithermal gold deposits, they are generally from the time period ranging from the middle Miocene to the Recent period., however notable exceptions are known. Most large-scale porphyry deposits have an age of less than 20 million years., however there are notable exceptions,…
Where do copper-gold deposits form?
Porphyry copper-gold deposits form in a variety of volcanic environments, most commonly in continental margins and intra-oceanic arcs.
