Sean Avitt

Sean Avitt - B.S.2009

Sean Avitt - B.S.2009

The Grasberg Mine, Papua, Indonesia is the largest single site gold deposit in the world and largest recoverable single site copper deposit in the world.

I collected and characterized 380 copper sulfide minerals from veins in the AM96-35-1, a unique horizontal drill core, which transects the three major intrusions and the high grade core of the Grasberg Cu-Au ore body, for copper isotope analysis. Those copper samples were analyzed by Dr. Todd Housh on an Isoprobe MC-ICP-MS.

This is the third study to be done at the Grasberg Mine using copper isotope systematics, and some of the results in this study have been found in direct contrast to a previous study, Graham et al. (2004).

Chalcopyrite, a primary copper sulfide sampled from the AM96-35-1 core from the Grasberg Igneous Complex.

Chalcopyrite, a primary copper sulfide sampled from the AM96-35-1 core from the Grasberg Igneous Complex.

Our results suggest that copper at the GIC is mantle-derived as has been similarly established at other copper deposits (Larson et al., 2003; Markl et al., 2006), but that host intrusions, distance from the core and coexisting mineral phases were found to have no measurable effect on copper isotope fractionation during precipitation of primary copper sulfide minerals at high temperatures.

Honors Advisor:

Dr. Mark Cloos