廣島大學地學研究報告 Issue 1
published_at 1951-03-26

石槌山近傍の第三紀火成岩類に就いて(豫報)

On the Tertiary Igneous Rocks in the Vicinity of Ishizuchi-yama, Shikoku (Preliminary Report)
Yoshida Hironao
fulltext
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GeoRepHiroshimaUniv_1_37.pdf
Abstract
1. The stratigraphical succession of rocks in the Ishizuchi-Yama region may be tabulated as follows.
[Original table is skipped. For more details, please refer to the full text.]
2. The volcanic activity of this region occurred synchronous with the sedimentation of Shibukusa-formation(Miocene).
3. Omogo intrusive mass was intruded after the effusion of biotite-augite-bearing hypersthene-andesite.
4. Omogo intrusive mass consists of fine-grained two mica-granite, biotite-augite-bearing hypersthene-porphyrite, augite-bearing biotite-hypersthene-diorite-porphyrite and augite-bearing biotite-hornbiende-hypersthene-granodiorite.
5. The gradual transition of biotite-augite-bearing hypersthene-porphyrite into augite-bearing biotite-hornblende-hypersthene-granodiorite is interpreted as the result of slow cooling and contamination.
6.Fine-grained two mica-granite is a residual product of biotite-augite-bearing hypersthene-porphyrite magma.
7. The heterogeneous appearance of biotite-augite-bearing hypersthene-porphyrite dues to crashed and elongated xenoliths.