A Petrofabric Study of Shear Micro-fold

SUZUKI Takashi

廣島大學地學研究報告

Geological report of the Hiroshima University

Quartz and calcite fabrics of shear micro-folds in a phyllite and a crystalline limestone from the Sambagawa Metamorphic Zone at Tai and Motoyama in Central Shikoku, were analysed. Partial and collective diagrams were made from the orientation data of the c axes of quartz grains and of the c axes and the {0112} twinned lamellae of calcite grains on the various sectors of the shear micro-folds. The patterns of fabric diagrams from the straight limb of fold are comparatively simple, while those from the knee of the fold are more complex. It is conceivable that in the knee the later shearing was too weak to obliterate completely the earlier fabric. The relationship between q-Richtungen and shear planes of a fold was also discussed.

英語

廣島大學理學部地學教室

[ISSN] 0073-2303

[NCID] AN00213676