| 赣中变质岩带地质地球化学演化特征 |
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| 关键词:metamorphic rock belt central Jiangxi element geochemistry isotopic geochemistry crystalline basement folded basement |
| 基金项目:福建省自然科学基金(编号:D0310017)，南京大学内生金属矿床成矿机制研究国家重点实验室开放基金，华侨大学自然科研资金(编号:02HZR01) |
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| Geological and Geochemical Evolution Characteristics of the Metamorphic Belt in Central Jiangxi |
| Isotope chronologic, geological and geochemical studies show that there exists a Middle Proterozoic crystalline basement in the deformation metamorphic belt of central Jiangxi and that after Middle Proterozoic the crystalline basement at least underwent 2 tectono-thermal events (Jinning and Caledonian). Petrochemical and REE studies demonstrate that the crystalline basement is mainly composed of parametamorphic rocks occasionally interlayered with orthometamorphic rocks. Folded basement rocks show increasing metamorphism at the center of the migmatite. There is a regular variation in petrochemical and REE composition from the crystalline basement to folded basement rocks, i.e. an increase of SiO_2 and K_2O+Na_2O and a decrease of TFeO+MgO+CaO+TiO_2, an increase of REE, LREE and LREE/HREE and a conversion from the slightly negative Eu anomaly to the strong one. An isotope geochemical study reveals a regular variation from the crystalline basement to folded-basement rocks, i.e., the values of ε_ Nd (0), ( 206 Pb/ 204 Pb)_i, ( 207 Pb/ 204 Pb)_i and ( 208 Pb/ 204 Pb)_i increase. The above characteristics also exhibit the tectonic evolution in central Jiangxi from island arc to active continental margins in the period from Middle Proterozoic to Sinian and Cambrian. |
| HU Gong-ren,LIU Cong-qiang,YU Rui-lian.2006.Geological and Geochemical Evolution Characteristics of the Metamorphic Belt in Central Jiangxi[J].Acta Geoscientica Sinica,27(1):35-42. |
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