Precambrian geological relationships in high‐grade gneisses of the Rauer Islands, east Antarctica
Precambrian geological relationships in high‐grade gneisses of the Rauer Islands, east Antarctica
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南极洲东部劳尔群岛高品位片麻岩的前寒武纪地质关系
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发表时间：
1987
期刊：
影响因子：
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通讯作者：
S. Harley
中科院分区：
文献类型：
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作者：
S. Harley
南极洲东部戴维斯基地附近劳尔群的片麻岩保留了复杂的构造变质和火成岩历史。基性麻粒岩和副片麻岩，保存在元古宙长英质正片麻岩的遗物和筏，在麻粒岩相条件下的两个早期变形幕（D1和D2）的影响。部分熔融的镁铁质岩石类型发生在这些事件之后，部分与同构造（D3）长英质正片麻岩的侵入同步。D3是导致该地区大部分片麻岩接近等斜褶皱的主要事件，在大于800°C和7-8 kbar的麻粒岩相条件下进行。初步的同位素数据表明，D3的年龄不超过1400 Ma。在D3后期及之后，在700 ℃下近等温减压至4 kbar的时期导致变质沉积片麻岩中产生浅色熔体，这发生在可能为晚元古代（1200-1000 Ma）的不协调基性岩墙侵入之前。更进一步地…
Gneisses from the Rauer Group, near Davis Base, east Antarctica, preserve a complex structural‐metamorphic and igneous history. Mafic granulites and paragneisses, preserved as relics and rafts within Proterozoic felsic orthogneisses, were affected by two early deformation episodes (D1 and D2) under granulite facies conditions. Partial melting of the mafic rocktypes occurred subsequent to these events and partly synchronous with the intrusion of syntectonic (D3) felsic orthogneisses. D3, a major episode which resulted in close to isoclinal folding of most of the gneisses in the area, progressed under granulite facies conditions of greater than 800°C and 7–8 kbar. Preliminary isotopic data indicate that D3 can be no older than 1400 Ma. A period of near‐isothermal decompression to 4 kbar at 700∘C late in and following D3 resulted in the production of leucocratic melts from metasedimentary gneisses, prior to the intrusion of discordant basic dykes of probable Late Proterozoic age (1200–1000 Ma). Further defor...