PETROLOGY OF DOLOMITIC MARBLES FROM KASUMI ROCK, PRINCE OLAV COAST, EAST ANTARCTICA

• Main Authors: ヒロイ ヨシクニ, コジマ ヒデヤス, Yoshikuni HIROI, Hideyasu KOJIMA
• Format: Report
• Language: English
• Published: Department of Earth Sciences, Faculty of Science, Chiba University 1988
• Subjects: East Antarctica; Prince Olav Coast; Kasumi Rock; Antarc*; Antarctica
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=2565; http://id.nii.ac.jp/1291/00002565/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=2565&item_no=1&attribute_id=18&file_no=1

Dolomitic marble containing primary chlorite, Zn-rich spinel and F-rich clinohumite occurs in the upper amphibolite-facies Kasumi Rock, Prince Olav Coast, East Antarctica. Minerals in the chlorite-bearing dolomitic marble along with another dolomitic marble from the Kasumi Rock were analyzed with an EPMA. Phase relations and vapor phase compositions are discussed in the light of experimentally determined phase equilibria and petrological data from other high-grade metamorphic terrains in East Antarctica and other areas. Mg-Fe partitioning between Ca-amphibole and other minerals is exceptionally irregular, and strongly depends on the Al-content of Ca-amphibole. The low-variance assemblage of the Kasumi Rock dolomitic marble buffered the vapor phase composition at low Xco_2 in harmony with that in the nearby calcite marbles. Spinels in the high-grade dolomitic marbles may have been produced by chlorite-consuming reactions during prograde metamorphism.