A Study of Sr, Nd and O Isotopes of the K-rich Melanocratic Dykes in the Late Mesozoic Gold Field in the Jiaodong Peninsula

被引：7

作者：

SUN Jinggui

机构：

来源：

Acta Geologica Sinica(English Edition) | 2001年 / 04期

关键词：

late Mesozoic; K-rich melanocratic dykes; Sr; Nd and O isotope geochemistry; gold field system in the Jiaodong Peninsula;

D O I：

暂无

中图分类号：

P618.51 [金];

学科分类号：

0709 ; 081803 ;

摘要：

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

引用

页码：432 / 444

页数：13

共 6 条

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