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Troctolite
Troctolite /ˈtrɒktəlaɪt/ (from Greek τρώκτης 'trout' and λίθος 'stone') 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.[1] 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,[2] the Stillwater igneous complex of Montana, the Duluth Complex of the North American Midcontinent Rift,[3] and the Tertiary Rhum layered intrusion of the island of Rùm, Scotland.[4] Troctolite is also found, for example, in the Merensky Reef of the Bushveld Igneous Complex, South Africa and in the Lizard complex in Cornwall.[5] References Wikimedia Commons has media related to Troctolite.
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