Division of Natural Environment, Faculty of Human Development, Kobe University
Geological Survey of Japan
Department of Earth and Planetary Sciences, Faculty of Science, Kobe University
Department of Earth Sciences and Astronomy, Fukuoka University of Education
Department of Resources Engineering, Faculty of Engineering, Tohoku University
抄録(英)
The Sør Rondane Mountains mainly consist of Proterozoic metamorphic rocks and various kinds of Late Proterozoic to Early Paleozoic granitic rocks. The Early Paleozoic granitic rocks can be divided into two types, concordant granites and discordant granites. Chemical analyses of major and trace elements for the Early Paleozoic granitic rocks are presented. The discordant granites are characterized by high Ba, Sr and alkalies. In contrast, the concordant granites are high in Y and Nb and slightly low in CaO, Cr and Sr compared with the discordant granites. Most of the concordant granites are classified as within plate granites and the discordant granites as volcanic arc granites, based on trace elements. Mineral compositions in the granitic rocks are also related to the two granite types. Mg/(Mg+Fe) ratios of ferromagnesian minerals of the concordant granites are very low, while those of the discordant granites have intermediate Mg/(Mg+Fe) ratios. Anorthite contents of plagioclases in the concordant granites are low, while those of the discordant granites have slightly high anorthite content compared with those of the concordant granites. These chemical features and the Sr initial ratios may suggest that these two granite types were formed under different conditions.
雑誌書誌ID
AA1072335X
雑誌名
Proceedings of the NIPR Symposium on Antarctic Geosciences
PRELIMINARY PETROLOGICAL STUDIES OF THE GRANITIC ROCKS IN THE SØR RONDANE MOUNTAINS, EAST ANTARCTICA
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KJ00002368351
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概要
