Petrology and geochemistry of basaltic rocks from the Balleny Is, Antarctica
Petrology and geochemistry of basaltic rocks from the Balleny Is, Antarctica
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南极洲巴勒尼岛玄武岩的岩石学和地球化学
DOI：
10.1080/08120099208728053
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发表时间：
1992
影响因子：
1.2
通讯作者：
T. Green
中科院分区：
文献类型：
--
作者：
T. Green
1978年刘易斯考察南极洲时，在巴利尼群的塞布丽娜和斯特奇岛采集的岩石样品是洋岛玄武岩，接近夏威夷玄武岩。一个值得注意的地球化学特征是Zr/Nb比值始终较低（≤ 3.5），而其他大洋岛屿碱性岩石的典型值为5.8（范围4.5-6.6）。Sturge样品是部分累积的，具有明显的单斜辉石和橄榄石斑晶。所有的岩石都是原生地幔熔体的衍生物，在中等压力（可能对应于地幔深度15-20公里）分馏的证据是由铝斜方辉石，铝（高铝VI）单斜辉石，钾长石角闪石和橄榄石的存在下提供的复杂的微量元素分带模式。氧化物相是多种多样的，从橄榄石中的Chrome尖晶石和斜长石中的铬尖晶石，到钛铁矿和钛磁铁矿的微斑晶。Balleny火山作用似乎代表了典型的热...
Rock samples obtained from Sabrina and Sturge Is in the Balleny Group, Antarctica during the 1978 Lewis Expedition are ocean island basanite, verging on hawaiite. A noteworthy geochemical feature is a consistently low Zr/Nb ratio (∼ 3.5) compared with a typical value of 5.8 (range 4.5–6.6) for other ocean island alkaline rocks of basanitic to alkaline basaltic composition. Sturge samples are partly cumulative, with conspicuous clinopyroxene and olivine phenocrysts. All rocks are derivative from primary mantle melts, and evidence for fractionation at moderate pressure (probably corresponding to mantle depths of 15–20 km) is provided by the presence of aluminous orthopyroxene, aluminous (high AlVI) clinopyroxene, kaersutitic amphibole and olivine with complex minor element zoning patterns. Oxide phases present are varied, from chrome spinel included in olivine and pleonaste included in plagioclase, to microphenocrysts of ilmenite and titanomagnetite. The Balleny volcanism appears to represent typical hot sp...