湘赣地区中生代基性岩地球化学特征与岩石圈厚度变化  

Geochemistry of the Mesozoic Mafic Rocks of and Lithospheric Thickness Variation in Hunan-Jiangxi Province

作　　者：刘勇[1] 李廷栋[1] 肖庆辉[1] 邢光福[2] 王涛[1] 寇彩化[1] 段政[2] 

机构地区：[1]中国地质科学院地质研究所,北京100037 [2]南京地质矿产研究所,南京210016

出　　处：《地质学报》2016年第9期2219-2232,共14页Acta Geologica Sinica

基　　金：国家自然基金项目湘赣地区中生代基性岩地球化学特征与软流圈界面变化(编号:41302045);地质志项目:主要地质单元区域地质调查与片区总结(编号:1212011120115);科技部项目科技基础性工作专项中国地质志;图及欧亚大陆大地构造图编制(编号:2011FY120100)联合资助的成果

摘　　要：湘赣地区中生代是多金属矿产的集中地区,是环太平洋成矿带的重要组成部分,该区中生代大规模成矿的最终制约因素来自地球深部，岩石圈厚度是探索地球深部的重要组成部分。本文通过湘南宁远玄武岩、长城岭辉绿岩和赣西北基性岩的研究，运用玄武岩主量元素对玄武岩的形成深度进行了定量模拟，初步探讨了湘赣地区中生代岩石圈厚度随时间的演化关系。研究表明，湘西南宁远地区晚三叠世岩石圈厚度约为53km，湘中南长城岭晚三叠世岩石圈厚度约为81～84km，赣西北早白垩世岩石圈厚度的形成深度约60～63km。The deep process is an ultimate restrictive factor for Mesozoic large scale petrogenesis and mineralization in Hunan and Jiangxi Provinces. Mesozoic polymetallic ore deposits in Hunan Jiangxi Provinces is an important component of metallogenic belt of the Pacific Rim, the ultimate constraints of Mesozoic large scale mineralization in the area from the deep Earth. Lithosphere structure is an important part of the deep Earth, and the lithosphere thickness is another important parameter of the lithospheric structure. Using the mantle melting column（Langmuir et al., 1992） model estimated the forming depth of basic rocks. By the Changchengling basalt and northwestern Jiangxi mafic rocks, using main elements of basalt, we make the depth quantitative simulation of depth of basalt formation, and study evolution of lithospheric thickness preliminary in Hunan Jiangxi Province. Combined with the previous geochronology, geochemistry and isotopic information, we can indicate that the lithosphere thickness is about 53 km in Southwest Hunan province of Late Triassic and 81-84 km in South Central Hunan province of Late Triassic and 60-63 km in Northwest Jiangxi province of Early Cretaceous.

关 键 词：玄武岩深度反演 中生代 岩石圈厚度 深部地质过程 美国科迪勒拉 地幔动态熔融模型 软流圈上涌 

分 类 号：P588.124[天文地球—岩石学] P313[天文地球—地质学]