PETROLOGY OF THE MUROTOMISAKI GABBROIC COMPLEX
PETROLOGY OF THE MUROTOMISAKI GABBROIC COMPLEX
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室御岬辉长杂岩的岩石学
DOI：
10.2465/ganko1941.67.218
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发表时间：
1972
期刊：
影响因子：
--
通讯作者：
T. Yajima
中科院分区：
文献类型：
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作者：
T. Yajima
室本分异的辉长岩杂岩位于四国岛室都崎角的极点。该杂岩时代侵入始新世Murotohanto群。杂岩的带状排列指示了重力下沉的分步结晶作用。杂岩的主要岩石类型有：冷凝边缘辉长岩、苦辉长岩、含橄榄辉长岩的细粒超辉长岩、含橄榄辉长岩的中粒超辉长岩、辉长岩伟晶岩和铁辉长岩。最新阶段的伟晶岩呈细脉状侵入。未发现白云母或反白云母粒状物，可观察到少量紫苏石作为内部析出物。橄榄石和辉石中的铁在杂岩的上部较为明显。在分馏过程中，钛铁矿是主要的不透明矿物，磁铁矿出现在最新阶段。在此基础上，研究了低蒸气压、低氧分压条件下橄榄石中铁精矿的分步结晶。
The Murotomisaki differentiated gabbroic complex locates at the extreme point of the Cape Murotomisaki, Shikoku Island. This complex intruded into the Murotohanto Group of Eocene in age. The zonal arrangement of which complex shows the indication of the fractional crystallization with gravitational sinking. Principal rock types of the complex are as follows: chilled marginal dolerite, picrite gabbro, fine-grained hyperathene bearing olivine augite gabbro, medium-grained hyperathene bearing olivine augite gabbro, augite gabbro pegmatite and ferrogabbro. The pegmatitic rocks of the latest stage intruded as small veins. Anygrain of pigeonite or inverted pigeonite is not found, whereas a small amount of hypersthene is observable as internal precipitates. Iron concentration in olivine and in augite is conspicuous at the upper part of the complex. Ilmenite is the predominant opaque minerals through the course of fractionation and magnetite appears at the latest stage. Fractional crystallization of OLIVINE THOLEIITE to intermediate iron concentration under low vapour pressure and low oxygen partial pressure is studied on these bases.