Role of volatiles in intrusion emplacement and sulfide deposition in the supergiant Norilsk-Talnakh Ni-Cu-PGE ore deposits [Publication]

August 18th, 2023

We have recently published a new summary on the formation of the Supergiant Norilsk-Talnakh orebodies. Read the full publication here: https://doi.org/10.1130/G51359.1 

Abstract:

The Norilsk-Talnakh orebodies in Siberia are some of the largest examples on Earth of magmatic Ni−Cu−platinum group element (PGE) deposits, formed by segregation of immiscible sulfide melts from silicate magmas. They show distinctive features attributable to degassing of a magmatic vapor phase during ore formation, including: vesiculation of the host intrusions, widespread intrusion breccias, and extensive hydrofracturing, skarns, and metasomatic replacement in the country rocks. Much of the magmatic sulfide was generated by assimilation of anhydrite and carbonaceous material, leading to injection of a suspension of fine sulfide droplets attached to gas bubbles into propagating tube-like host sills (“chonoliths”). Catastrophic vapor phase exsolution associated with a drop in magma overpressure at the transition from vertical to horizontal magma flow enabled explosive propagation of chonoliths, rapid “harvesting” and gravity deposition of the characteristic coarse sulfide globules that form much of the ore, and extensive magmatic fluid interaction with country rocks

And here is a “video abstract” that simply visualises some of the formation processes we discuss in the paper.

Where:

  • the oil is our silicate magma,
  • water is the sulfide liquid,
  • red dye are the metals and PGEs and
  • the effervescent tablet is the introduction of volatiles.

video from:

Beautiful Chemical Reaction Using Household Materials