鲁东晚中生代热隆-伸展构造及其动力学背景  

Late Mesozoic Thermal Upwelling-Extension Structure and Its Dynamics Background in Eastern Shandong Province

作　　者：宋明春 李杰 李世勇 丁正江 谭现锋 张照录[6] 王世进[7] Song Mingchun;Li Jie;Li Shiyong;Ding Zhengjiang;Tan Xianfeng;Zhang Zhaolu;Wang Shijin(Shandong Provincial Bureau of Geology ＆ Mineral Resources/Shandong Provincial Engineering Research Center for Geological Prospecting,Jinan 250013,China;College of Resources,Hebei University of Geosciences,Shijiazhuang 050031,China;Shandong Institute of Geophysical and Geochemical Exploration,Jinan 250013,China;No.8 Shandong Provincial Exploration Institute of Geology and Mineral Resources,Rizhao 276826,Shandong,China;Lunan Institute of Geology and Engineering Investigation of Shandong,Jining 272100,Shandong,China;College of Resources and Environmental Engineering,Shandong University of Technology,Zibo 255000,Shandong,China;Shandong Institute of Geological Survey,Jinan 250013,China)

机构地区：[1]山东省地质矿产勘查开发局/山东省地质勘查工程技术研究中心,济南250013 [2]河北地质大学资源学院,石家庄050031 [3]山东省物化探勘查院,济南250013 [4]山东省第八地质矿产勘查院,山东日照276826 [5]山东省鲁南地质工程勘察院,山东济宁272100 [6]山东理工大学资源与环境工程学院,山东淄博255000 [7]山东省地质调查院,济南250013

出　　处：《吉林大学学报（地球科学版）》2018年第4期941-964,共24页Journal of Jilin University：Earth Science Edition

基　　金：山东省重点研发计划项目(2017CXGC1604);泰山学者建设工程专项经费(ts201511076)

摘　　要：为理清山东省鲁东地区晚中生代构造-岩浆-成矿的关系及其发生的动力学背景,本文综合分析了晚中生代侵入岩的空间分布、组合特征、成因类型、形成时代和序列、地球化学演化及形成的构造环境等。研究表明:该区侵入岩由侏罗纪陆壳重熔型花岗岩、白垩纪壳幔混合型花岗岩、白垩纪深源花岗岩和白垩纪脉岩组成,并且从早期到晚期,侵入岩的岩石化学成分由高钾钙碱性系列向橄榄安粗岩系列演化,微量元素由高Ba、Sr花岗岩向低Ba、Sr花岗岩演化,稀土元素由无或弱正铕异常向显著负铕异常演化,岩浆岩成因由S型向I型、A型演化。强烈的岩浆活动和复杂的岩浆岩类型指示了剧烈的壳幔相互作用过程,认为鲁东地区在早白垩世处于强烈的拉张构造环境,其在140~110 Ma期间大规模岩浆活动的同时发生了强烈的地壳隆升事件。通过对断陷盆地、火山活动、变质核杂岩和断层系统的类型、性质、控制因素等进行综合分析,提出它们是大规模伸展构造的表现形式,伸展构造的活动时间为130~98Ma。进一步分析表明,鲁东地区的白垩纪构造-岩浆组合构成了热隆-伸展构造,它们是太平洋板块俯冲与燕山运动主变形时期(岩石圈增厚)后续效应的产物,岩石圈拆沉、地壳减薄和克拉通破坏是引起早白垩世热隆-伸展构造的根本原因,热隆-伸展构造为胶东大规模成矿提供了有利条件。In order to understand the Late Mesozoic tectonic-magmatic-mineralization and its dynamic background in the eastern Shandong Province, the authors analyzed the spatial distribution, assemblage characteristics, genetic types, formation times and sequences, geochemical evolution, and tectonic environment of the Late Mesozoic intrusive rocks. The intrusive rocks are mainly composed of Jurassic continental crust-remelted type granites, Cretaceous crust-mantle mixed granites, Cretaceous alkali granites, and Cretaceous vein rocks. From early to late period of magma activities, the intrusive rocks evolved from the high potassium calc-alkaline series to the shoshonite series, from the high Ba-Sr granites to the low Ba-Sr granites, from the no or weak positive Eu anomalies to the higher Eu negative anomalies, and from the S type granites to I and A type granite. The strong magmatism and various magmatic rock types indicate the occurrence of mantle-crust interaction. It is considered that the eastern Shandong was in a strong tensional tectonic background in Early Cretaceous, and the crust uplifted significantly with large-scale magmatic activities in the period of 140-110 Ma. According to a detailed research of the types, properties and control factors of the faulted basin, volcanism, metamorphic core complex and fault systems, the large-scale extensional structure was formed in 130-98 Ma. Further, the authors points out that the Cretaceous tectono-magmatic combination constituted the thermal upwelling-extension structure in the eastern Shandong province,which was the product of the combined effect of the Yanshannian intracontinental orogeny and the subduction of the Pacific plate. The lithosphere delamination, crust thinning and craton destruction were underlying causes of the Early Cretaceous thermal upwelling-extension structure, which provided the favorable conditions for the large-scale metallogenesis in the eastern Shandong Province.

关 键 词：热隆-伸展构造 晚中生代 岩浆活动 地壳隆升 燕山运动 鲁东 

分 类 号：P548[天文地球—构造地质学]