First identified in 1969, komatiites are Earth's oldest known volcanic rocks and contain three times as much magnesium as do most volcanic rocks.
科马提岩于1969年首次被发现，它是地球上已知的最古老的火山岩，含镁量是大多数火山岩的三倍。
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The Jifeng komatiites are situated in the north Da Hinggan Ling.
本文研究的科马提岩位于大兴安岭北段吉峰地区。
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The komatiites were formed in Mesoproterozoic, in a tectonic environment of tensile crust, while ther ising komatiite magma was quenched a nd rapidly cooled.