Geochemical features of the Neoproterozoic igneous rocks from the Wudang region and their implications for the reconstruction of the Jinning tectonic evolution along the south Qinling orogenic belt.
武当地区新元古代岩浆岩地球化学特征及其对南秦岭晋宁期区域构造性质的指示

A comprehensive study of geochemistry was made on a series of the Jinning period (1. 0~0. 75Ga) igneous rocks from the Wudang region, South Qinling Orogenic belt (SQOB). It shows that the volcanics of Wudang Gp, aged ca. 1. 0-0. 95 Ga, have the affinities of arc magmas , and could be compared, in terms of geochemistry and ages, with those from the adjacent Xixiang Gp located at the northern margin of the Yangtze craton (NMYC) and Mogouxia volcanics from SQOB in Shanxi province. Yaolinghe volcanics and Wudang mafic dikes, which emplaced into both Wudang and Yaolinh Gps, share the magma characteristics of the continental rift, and are thought to be the equivalents of Tiechanshan alkaline volcanics and Wangjiangshan mafic swarms from the NMYC, which were radiometriolly dated as ca. 0. 82-0. 78 Ga. The similar experience in tectonic evolution from subduction zone transforming to continental rifting in the two regions indicates that the NMYC and SQOB belong to a unigue continental block, even though the later one is earmarked of strong deformation due to the Phanerozoic orogeny. TDM model ages of ca. 1. 2~0. 9 Ga and high positive ENd values for the Neoproterozoic igneous rocks of the Wudang region demonstrate that the Jinning events played extremely significant role in both crust growth and lithosphere evolution of the regiona.