SUN Jinggui,HU Shouxi,LIU Jianmin,SHEN Kun and LING Hongfei Earth Science Institute,Jilin University,Changchun 130062 State Key Laboratory of Research on Metallogenesis of Endogenic Ore Deposits,Nanjing University,Nanjing 210093 Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100101 Shandong Institute and Laboratory of Geological Sciences,Jinan 250013
P618.51
Geologic, petrographic and petrochemical studies of the late Mesozoic K-rich melanocratic dykes, including lamprophyres, andesite porphyrites and dacite-porphyry in the gold field system in the Jiaodong Peninsula, China, have shown that these dykes are characterized by rich potassium and alkali but poor titanium. They belong to an ultra-high potassic, shoshonitic and high potassic calc-alkaline rock series. The parental magma has relatively high initial strontium ratios ((87Sr/86Sr)i=0.70895-0.71140) and low (143Nd/144Nd)i ratios (varying from 0.51135 to 0.51231); and its δ18OSMow. whole rock values vary from +5.8‰ to +10.6‰ with a mean of+7.1‰. These features suggest that the source region of the magma is an enriched mantle wedge transformed from a continental lithosphere mantle which has experienced metasomatism by mantle-derived fluids with H2O-dominated fluids that were provided during the underthrusting of an ocean crust. The initial magma was generated by low-degree partial melting of the enri
SUN Jinggui, HU Shouxi, LIU Jianmin, SHEN Kun, LING Hongfei Earth Science Institute, Jilin University, Changchun State Key Laboratory of Research on Metallogenesis of Endogenic Ore Deposits, Nanjing University, Nanjing Institute of Geology, Geophysics, Chinese Academy of Sciences, Beijing Shandong Institute, Laboratory of Geological Sciences, Jinan .2001. A Study of Sr, Nd and O Isotopes of the K-rich Melanocratic Dykes in the Late Mesozoic Gold Field in the Jiaodong Peninsula[J]. Acta Geologica Sinica(),75(4):
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