Metamorphic and Plutonic Rocks in the Cape Omega Area, East Antarctica

• Main Author: Morihisa Suzuki
• Format: Report
• Language: English
• Published: Institute of Geology and Mineralogy, Faculty of Science, Hiroshima University 1979
• Subjects: East Antarctica; Syowa Station; Ongul; Ongul Island; East Ongul Island; Cape Omega; Antarc*; Antarctica; Memoirs of National Institute of Polar Research; Polar Research
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=1027; http://id.nii.ac.jp/1291/00001027/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=1027&item_no=1&attribute_id=18&file_no=1

The Cape Omega area is situated at about 80km northeast of Syowa Station, East Ongul Island. The area is composed of various kinds of metamorphic and plutonic rocks. Total thickness of constituent rocks can be estimated to be 2000m at least. Metamorphites are derived from basic, pelitic, psammitic and calcareous sedimentary equivalents. So-called metabasites are also the characteristic member among the metamorphites in the area. Plutonic rocks are mainly gneissose granite, pink granite and pegmatite. The area is characterized by the existence of macroscopic folds, their axes trending approximately E-W. The axes coincide with the trend of lineations and that of β-maximum for the gneissosity. Judging from the mineral association and mineralogical characters of metamorphites, general metamorphic grade is as high as the amphibolite facies. The granulite facies rocks, however, have been preserved among the ubiquitously distributed amphibolite facies ones. Time and spatial relationship between the two metamorphisms of different grade has been clarified in terms of polymetamorphism.