拉薩地塊和羌塘地塊多個二疊紀基性巖及一個古特提斯海山的初步古地磁結果：對模擬東岡瓦納晚古生代裂解的暗示

拉薩地塊和羌塘地塊多個二疊紀基性巖及一個古特提斯海山的初步古地磁結果：對模擬東岡瓦納晚古生代裂解的暗示

* Corresponding author. E-mail: chungd@hku.hk.

Preliminary Paleomagnetic Results from Various Permian Mafic Units on the Lhasa and Qiangtang Blocks, plus a Paleotethyan Sea-mount: Implications for Modeling Eastern Gondwana’s Late Paleozoic Breakup

Diane CHUNG1)*, Jason R. ALI1), Jonathan C. AITCHISON2)
1)Department of Earth Sciences, University of Hong Kong, Pokfulam Road, Hong Kong, P.R. China;
2)School of Geosciences, University of Sydney, Sydney, NSW2006,Australia

Detachment of the sliver-like Cimmerian terrane from eastern Gondwana in the Early Permian triggered mafic volcanism in many parts of the rift zone. To understand this tectonic episode we have carried out paleomagnetic investigations on mafic volcanic formations that were erupted on key terranes that now form part of Tibet. Specifically, we will present data from sections near Lhasa City (central Lhasa block)and Tuotuohe (central Qiangtang Block) as well as near Gyanyima (Paleotethyan sea-mount) that was emplaced onto the floor of Palaeotethys during the Late Permian. Paleomagnetic plots from each location will be used for tectonic calculations. Our new data will be used to evaluate regional scale models concerned with how the Cimmerian terranes in southern and SE Asia (from Iran-Tibet-SW China-Myanmar-Thailand-Sumatra) formerly abutted eastern Gondwana.

Paleomagnetism; mafic units; Permian; Lhasa Block; Qiangtang Block; Gyanyima

10.3975/cagsb.2012.s1.05