Troctolite

Troctolite 76535 from the Apollo 17 landing site

Troctolite is a mafic intrusive rock type. It consists essentially of major but variable amounts of olivine and calcic plagioclase along with minor pyroxene. It is an olivine-rich anorthosite, or a pyroxene-depleted relative of gabbro. However, unlike gabbro, no troctolite corresponds in composition to a partial melt of peridotite. Thus, troctolite is necessarily a cumulate of crystals that have fractionated from melt.

Troctolite is found in some layered intrusions such as in the Archean Windimurra intrusion of Western Australia, the Voisey's Bay nickel-copper-cobalt magmatic sulfide deposit of northern Labrador,[1] the Stillwater igneous complex of Montana and the Tertiary Rhum layered intrusion of the island of Rùm, Scotland.[2] Troctolite is also found in the Merensky Reef of the Bushveld Igneous Complex, South Africa and in the Lizard complex in Cornwall.[3]

References

Wikimedia Commons has media related to Category:Troctolite.
This article is issued from Wikipedia - version of the Tuesday, November 10, 2015. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.