古亚洲洋早古生代太平洋型地幔：来自新疆北部蛇绿岩Sr-Nd-Pb-Hf同位素的限定

印度洋地幔域和太平洋地幔域的划分为探讨古洋域地幔的归属提供了依据。古亚洲洋地幔域晚古生代为印度洋型地幔特征，然而其早古生代的地幔属性还不清楚。本项目拟选择新疆北部早古生代古亚洲洋蛇绿岩，对其基性岩进行全岩和单矿物主微量元素及Sr-Nd-Pb-Hf同位素研究，厘定古亚洲洋地幔域早古生代地幔特征，结合蛇绿岩精细年代学研究从时间尺度上追踪古亚洲洋地幔域的地幔演化差异，本项目将为理解早古生代期间古亚洲洋地幔归属和中亚造山带深部地球动力学背景提供重要的科学依据。

Classification of Indian- and Pacific-type mantle domains gives a basic principle to define the ancient oceanic mantle domain. The Paleo-Asian mantle domain shows an Indian-type characteristics during the late Paleozoic, however, the property of its early Paleozoic mantle domain is still ambiguous. This project will focus on the early Paleozoic Paleo-Asian ocean ophiolite from north Xinjiang region of China. We plan to analyze the major and trace elements and Sr-Nd-Pb-Hf isotopic ratios of the bulk rock and mineral separates from mafic rocks in these ophiolites in order to constrain the nature of Paleo-Asian sub-oceanic mantle. Moreover, these information combined with detailed ophiolite geochronologic data will provide tracers on the evolution of the Paleo-Asian mantle domain through time and this in turn will provide stringent constraints on the possible cause of the mantle distinction. Therefore, this project will lead a better understanding of mantle conditions in the Paleo-Asian Ocean during early Paleozoic as well as promote geodynamic research in Central Asia.