Geochemistry of syenite of the Phalaborwa Carbonatite Complex, South Africa

• Main Authors: Masaki Yuhara, Mika Kohno, Hiroo Kagami, Yoshikuni Hiroi, Noriyoshi Tsuchiya
• Format: Report
• Language: English
• Published: Department of Earth System Science, Faculty of Science, Fukuoka University/National Institute of Polar Research/Graduate School of Science and Technology, Niigata University/Department of Earth Sciences, Faculty of Science, Chiba University/Department of Geoscience and Technology, Graduate School of Engineering, Tohoku University 2003
• Subjects: mineral chemistry; whole-rock chemistry; syenites; Phalaborwa; South Africa; Polar geoscience
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=3128; http://id.nii.ac.jp/1291/00003128/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=3128&item_no=1&attribute_id=18&file_no=1

We surveyed the Spitskop syenite pipe,one of the satellite bodies of the Phalaborwa Carbonatite Complex located in northeastern Transvaal,South Africa. This pipe is composed of the inner cumulus syenite and outer ring syenite.The brecciation zone between these syenites includes many blocks of syenite,pyroxenite, melanocratic rock,biotite gneiss and granitic rocks.Dolerite dykes intruded into the plug and brecciation zone.Fine-and coarse-grained syenites,melanocratic rock, alkali-feldspar granite and dolerite were collected from the brecciation zone of this pipe.The whole-rock and mineral chemistry suggests that syenites and melanocratic rocks of the brecciation zone were derived from the inner cumulus syenite magma. These rocks do not indicate any clear isochron.It may be a result of mixing of various rocks at the brecciation stage.