TSXV:KAM - Post Discussion
Post by
stargazer1 on Nov 04, 2018 3:52pm
testing
In the high temperature and pressure of the magma, the intensely hot brine becomes very reactive and the chlorine in it (NaCl) scavenges and concentrates metals into its solution. Even normally inactive gold, forms soluble compounds, such as hydrogen gold chloride (HAuCl2). The brine also absorbed the metal enriched sulfur as it circulated through the hot magma.
Porphyry ore deposits form over durations of a few hundred thousand years, to periods of several million years. Giant porphyry ore deposits require sufficiently long periods to accumulate large ore deposits.
The magma producing events that formed the Pebble ore deposit extended over a time scale of three million years, which is longer than the duration of most porphyry producing episodes. Fresh, metal rich plumes of magma, repeatedly rose from the deep magma chamber, mixing in with the magma that was forming the Pebble deposit, and preventing it from cooling and solidifying. For millions of years, additional metal was repeatedly added to the Pebble deposit, eventually making it the largest ore deposit that has ever been discovered.
These plumes of hot magma rose toward the surface. The plume of magma that formed the Pebble deposit ended up at a depth of 3.8 kilometers (2.4 miles). That close to the surface, the pressure was low enough that the brine came out of solution in the hot magma, in the form of a hot vapor.
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