Nghiên cứu các đá plagiogranit phức hệ Điệng Bông trong khu vực. Các kết quảcủa công trình này cùng với các kết quả nghiên cứu trước đây trong đới khâu Tam Kỳ - Phước Sơn cho thấy sự tồn tại của kiểu magma: Cung đảo, cung lục địa và kiểu vỏ đại dương trong rìa bắc địa khối Kon Tum. | Journal of Mining and Earth Sciences Vol. 62 Issue 5 2021 1 - 11 1 Cr - spinel and clinopyroxene compositions from metagabbro of Nui Ngoc complex in Tam Ky area evidence of island - arc magma Thanh Xuan Ngo 1 Du Khac Nguyen 1 Dao Anh Vu 1 2 Chi Thi Pham 3 Hanh Hong Thi Nguyen 3 Dung Ngoc Pham 3 1 Faculty of Geosciences and Geoengineering Hanoi University of Mining and Geology Vietnam 2 Graduate Institute of Geophysics National Central University Taiwan 3 Vietnam Institute of Geosciences and Mineral Resources Vietnam ARTICLE INFO ABSTRACT Article history The hornblende and biotite - bearing metagabbro of the Nui Ngoc complex Received 08th July 2021 were exposed into a few small blocks in the southwest Tam Ky city and were Accepted 19th Sept. 2021 viewed as parts of the Tam Ky - Phuoc Son ophiolitic complex TPO . These Available online 31st Oct. 2021 rocks were undergone mylonitic deformation and metamorphism. The Keywords rocks consist mainly of orthopyroxene clinopyroxene plagioclase olivine Cr - spinel hornblende biotite and very few microscopic Cr - spinel. The clinopyroxene and Cr - spinel minerals were analyzed for their composition by EPMA the Early Paleozoic results showed that 1 The clinopyroxenes have low Al2O3 3 2 3 5 wt Ophiolit TPSZ TiO2 0 70 0 82 wt contents and 2 the Cr - spinels have low TiO2 Pyroxen 0 23 0 58 wt content and Mg 100 Mg Mg Fe2 32 42 but has Tam Ky - Phuoc Son. medium Cr Cr Cr Al 45 52 .These features are similar to those of rocks formed in anoceanic - oceanicsubduction zone that was reported for the plagiogranite of Dieng Bong complex nearby. This study results combined with previous research results in the Tam Ky - Phuoc Son suture zone show the existence of island arc continental arc and MOR - magmatic types. Copyright 2021 Hanoi University of Mining and Geology. All rights reserved. _ Corresponding author E - mail ngoxuanthanh@ DOI 5 .01 2 Tạp chí Khoa học Kỹ thuật Mỏ - Địa chất Tập 62 Kỳ 5 2021 1 -
