应大陆碰撞与高原隆升重点实验室丁林研究员邀请,缅甸曼德勒大学Hnin Min Soe教授来青藏高原所交流并做学术报告。
Title: Metamorphic Rocks Exposed at Kumon Range and Katha-Gangaw Range, Myanmar
Speaker: Dr Hnin Min Soe
Department of Geology, University of Mandalay, Myanmar
Host Institute: Dr. Ding Lin
Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China
时间:4月25日(星期二)上午 8:30 (Meeting time: 8:30 A.M April 25)
地点:915会议室(Meeting Room: 915)
Hnin Min Soe is a Professor of Geology Department at Mandalay University, Myanmar. She finished B.Sc. Honours (Geol.) degree in 1995 and M.Sc. (Regional Geol.) in 1999 at Mandalay University and PhD degree, (Economic Geology) in 2008 at Yangon University. She has about 12 publications of local journals in Myanmar. Dr. Hnin has been working research about Complete Ophiolite suite exposed at Mayhka-Malihka Confluence, Myitkyina area, Northern Myanmar. Her interest is the study of Kumon Range and Katha-Gangaw Range not only metamorphism of the pelitic rocks but also the tectonic evolution of these areas and its environments. Most of these areas have not been yet up to now by EPMA methods especially schist units that have not been done in Myanmar.
Kumon Range is generally made up of pelitic metamorphic rocks, low to medium grade, regionally metamorphosed schist and quartzite with minor amount of metabasite, eclogite and metagranite as lenes or exotic block. Among them, an isolated and unmappable exposure of eclogite unit in metapelitic schist is found at Mogaung area, Mogaung and Phakant Townships, Kachin State. This area is bounded by N 25o 20? to 25o 30′ and E 96o 47′ to 97o 00′, it is also a southern extremity of Kumon Range. This unit occurred as tectonic blocks intruded by quartz veins, associated with garnet biotite augan gneisses and metagranites. It provides evidence of high-pressure metamorphism in this region for the first time, according to Aung Win 2008, P-T conditions for the formation of eclogite is 23 kbar at 427oC in the initial stage of eclogite metamorphism and 23 kbar at 493oC indicating that the rock was subducted to 85 km depth. High-pressure, low-temperature metamorphic conditions of the eclogite imply the presence of a major convergent tectonic boundary where the eclogite was formed (Aoya & Wallis, 2003). And also the Katha-Gangaw Range (KGR) is mainly built up of meta-sedimentary rocks. These rocks can be subdivided into three units based on the dominant minerals and lithologies as Unit I – Graphite schist and garnet staurolite- schist, micaceous quartzite, Unit II- garnet mica schist, garnet bearing quartzite and quartz mica schist and Unit III- Chlorite schist, talc schist, garnet graphite schist and quartzite. Medium to high pressure metamorphic rocks exposed in the Assam region and Indo-Myanmar ranges are rather similar to the medium to high pressure and low to high temperature metamorphic rocks exposed at Kumon Range, Katha-Gangaw Range and Tagaung-Twinnge areas. So far it can be accepted the suggestions of Mitchell (1993) that the metamorphic rocks of the Kumon, Katha-Gangaw Ranges are the northern offset continuation of the metamorphic rocks of the western Indo-Myanmar Ranges. However it is still needed to detect more information to confirm this document and later plan for the study of Kumon Range and Katha-Gangaw Range is not only progressive metamorphism of the politic rocks but also the tectonic point of these areas and its environments. The main aim of future plan is collaboration of research projects on these areas with Myitkyina University, Mandalay University and Institute of Tibetan Plateau Research,Chinese Academy of Sciences, Beijing, China.
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大陆碰撞与高原隆升重点实验室