A melilite-bearing high-temperature calcic skarn, Camasunary Bay, Isle of Skye
A melilite-bearing high-temperature calcic skarn, Camasunary Bay, Isle of Skye
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斯凯岛卡马苏纳里湾含有黄长石的高温钙质夕卡岩
DOI：
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发表时间：
2007
影响因子：
0.7
通讯作者：
Simon M. Drake
中科院分区：
文献类型：
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作者：
A. Beard;Simon M. Drake
高温钙质矽卡岩的出现相对罕见，全世界约有30个报告。在这里，我们报告一个新发现的发生在Camasunary湾，斯凯岛的黄长石轴承高温钙质矽卡岩。接触变质作用是由Cuillin山辉长岩的侵入和后来的Coire Uaigneich花岗斑岩的侵入引起的。钙夕卡岩由硅灰石、奥氏钙铝黄长石、紫苏钙长石、钛铁矿、尖晶石等高温矿物组合组成。钙铁榴石-钙铝榴石石榴石、钙钛矿和钙钛矿。它还包括非常罕见的富Zr石榴石金伯利岩和baghdadite（Ca 3（Zr，Ti）Si 2 O 9），表明来自含水Coire Uaigneich花岗斑岩的Zr，Ti和其他不相容的富元素流体的转移。钙质夕卡岩中含有大量的硅质结核和细脉，它们与在斯凯岛其他地区观察到的寒武-奥陶纪白云岩暴露非常相似。表明原岩最初是不纯的白云石。钙质夕卡岩和周围托里东沉积岩之间的接触性质无法直接观察到，但在斯凯岛的其他地方，这种接触是基斯霍恩逆冲断层面。这对英国地质调查局布罗德福德地图（第71 W页）附带的简化构造图有影响，现在需要修改。
Synopsis The occurrence of high-temperature calcic skarns is relatively rare, with around 30 being reported worldwide. Here, we report on a newly discovered occurrence of a melilite-bearing high-temperature calcic skarn at Camasunary Bay, Isle of Skye. The contact metamorphism was caused by the intrusion of the Cuillin Hills gabbro and the later intrusion of the Coire Uaigneich granophyre. The calcic skarn consists of a high-temperature assemblage of wollastonite, åkermanite–gehlenite, vesuvianite, tilleyite, spurrite. andradite–grossular garnet, monticellite and perovskite. It also includes the very rare Zr-rich garnet kimzeyite and baghdadite (Ca3(Zr,Ti)Si2O9), indicating transfer of Zr, Ti and other incompatible element-rich fluids derived from the hydrous Coire Uaigneich granophyre. The calcic skarn contains numerous cherty nodules and stringers, which bear a remarkable resemblance to the Cambrian–Ordovician dolostone exposures observed in other parts of Skye. suggesting that the protolith was originally an impure dolomite. The nature of the contact between the calcic skarn and surrounding Torridonian sedimentary rocks could not be directly observed, but elsewhere on Skye this contact is the Kishorn Thrust plane. This has implications for the simplified tectonic map accompanying the British Geological Survey map of Broadford (Sheet 71W), which now requires modification.