The FAMOS project approach

Apatite crystals

Microscopic cathodoluminescence image of apatite crystals (yellow) within pink-luminescent anhydrite from The Resolution porphyry copper-molybdenum deposit, Arizona, USA. Apatite can record a number of properties of the magma from which it grew and is one of the minerals studied in the project. © Matthew Loader

 

How do metals accumulate in magma?

Magmas are formed at subduction zones, where one tectonic plate descends beneath another, and where volcanoes and earthquakes are produced.

We will study the environments above subduction zones, associated with volcanic arcs. This is where the crust is thought to be full of mushy magma, rich in crystals and volatiles like water and carbon dioxide.

The key goal is to understand how the metals of interest are enriched in these magmas and then transferred to the water-rich liquids from which the ore minerals are finally deposited.

The analysis of natural minerals will be supported by high-pressure and -temperature experiments designed to simulate conditions found deep in the Earth’s crust.

We will also develop computer models to explore the physics of how mushy magmas and metal-rich fluids migrate through the Earth's crust on their way towards the surface.

What conditions led to the formation of ore deposits?

A special set of conditions allow a typical arc magma to evolve to the point where an ore deposit can form.

We aim to identify when and where these conditions might have existed by analysing the chemical fingerprints in minerals, that lock-in information as they crystallise.

The 'Gates' concept

The project will examine the special conditons required at each stage of the deposit formation, and how these processes might be studied. The diagram below shows the pathway from subduction zone to final ore formation.

famos-gates-diagram

A conceptual diagram showing crustal environments, mineral system 'gates' (numbered), and possible mineral & textural proxies

Project summary

  • Focus: To develop new exploration tools for mineral resouces by understanding the processes by which metals are concentrated in magmatic arcs.
  • Funding: NERC
  • Start date: 1 May 2017
  • End date: 30 April 2021