The ruby and pink sapphire deposits of SW Greenland : geological setting, genesis, and exploration techniques ...

• Main Author: Fagan, Andrew Jeffrey
• Format: Text
• Language: English
• Published: University of British Columbia 2018
• Subjects: Fiskenæsset; Greenland
• Online Access: https://dx.doi.org/10.14288/1.0372956; https://doi.library.ubc.ca/10.14288/1.0372956

The Aappaluttoq, Siggartartulik, and Kigutilik gem corundum deposits are hosted by the Fiskenæsset Anorthosite Complex in SW Greenland. These deposits are some of the largest ruby and sapphire deposits in the world yet have received little scientific attention. During regional granulite metamorphism (2817 Ma; U-Pb EMPA monazite), leucogabbroic rocks alter towards more Na-enriched compositions causing Ca-feldspar to recrystallize. This liberates the Al required for metamorphic opaque corundum formation in an orthogneissic host. Subsequent retrogression through the amphibolite facies (2747-2555 Ma, U-Pb EMPA monazite) and local scale hydrous metasomatism (2660 Ma, U-Pb EMPA monazite) causes recrystallization of the mineral assemblage and the formation of three distinct gem corundum bearing lithologies: 1) phlogopitite, 2) altered leucogabbro, 3) altered ultramafic rock containing sapphirine and gedrite-anthophyllite. Intrusion of local granitoids (2747-2714 Ma, U-Pb TIMS zircon) provided a hydrous fluid which ...