A peridotitic komatiite from the Dalradian of Shetland
A peridotitic komatiite from the Dalradian of Shetland
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产自设得兰群岛达尔拉迪安的橄榄岩科马提岩
DOI：
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
D. Moffat
中科院分区：
文献类型：
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作者：
D. Flinn;D. Moffat
科马提岩熔岩产于坎宁斯堡地区设得兰群岛东南部的邓罗斯内斯细碧岩群中。该变质火山群是设得兰群岛东大陆继承系的最东端成员，也可能是最年轻的。它覆盖着一层很厚的深水变质沉积层和变质火山岩，可能形成了一个伸展盆地的一部分，并与苏格兰上达尔拉德的一部分相关联。科马提岩在如此年轻的岩石序列中并不常见。它们的喷发被认为需要自太古代以来不寻常的构造和热条件。当伸展盆地下的地壳分裂形成建设性边缘时，就可能出现这种情况。
Komatiite lavas occur in the Dunrossness Spilitic Group in southeast Shetland in the Cunningsburgh area. This metavolcanic group is the easternmost member of the East Mainland Succession of Shetland and probably the youngest. It overlies a thick succession of deep-water metasediments and metavolcanic rocks probably forming part of an extensional basin and has been correlated with a part of the upper Dalradian of Scotland. Komatiites are not common in rock sequences as young as this. Their eruption is thought to require tectonic and thermal conditions which have been unusual since Archean times. Such conditions could arise when the crust beneath an extensional basin splits to form a constructive margin.