Tectonic settings of the basic igneous rocks in the Kudi ophiolite zone of West Kunlun Mountains, Xingjiang Province.
新疆西昆仑库地混杂带中基性火山岩构造环境分析

The basic igneous rocks, outcropped in Yexikegou, northwest of Kudi, is one of the most important components of the tectonically separated Kudi ophiolite in west Kunlun which is considered the northernmost border of the Gandwana plate as well as the oldest suture zone found in Tibet Plateau. So far, a lot of different opinions about its tectonic settings have been presented by different researchers, which gives rise to much confusion on the understanding upon its origin and evolutionary history. To clarify such confusion, a detailed field survey upon the geological section of the igneous rocks in Yexiekegou was conducted. In this paper, we use geochemical data from XRF, ICP-MS and Sm/Nd isotope analysis as well as the published data in this area to make a synthetical determination upon its tectonic settings. Through different tectonic discriminant diagrams based upon major and trace element compositions of Yexiekegou basic igneous rocks together with their isotopic characteristics, accordant results can be obtained that they were formed in an oceanic island-arc tectonic environment. Therefore, it provides some new evidences for the constraint on the origin of Kudi ophiolite.