新华夏构造体系结构面“米字型”分布与演化的数学模拟研究  

Numerical Simulation on Distribution and Evolution of Double-cross Surface Pattern in the Neo-Cathaysian Structural System

作　　者：吕古贤[1] 王红才[1,2] 韩璐 张宝林 胡宝群[4] 吕承训[5] 马立成 焦建刚[6] 毕珉峰[7] Lü Guxian;WANG Hongcai;HAN Lu;ZHANG Baolin;HU Baoqun;Lü Chengxun;MA Licheng;JIAO Jiangang;BI Minfeng(Institute of Geomechanics,Chinese Academy of Geological Sciences,Beijing100081,China;Key Laboratory of Neotectonic Movement and Geohazard,Beijing100081,China;Key Laboratory of Mineral Resources,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing100029,China;School of Earth Sciences,East China University of Technology,Nanchang,Jiangxi330013,China;Geological Survey Center,China Geological Survey,Beijing100037,China;School of Earth Sciences and Resources,Chang'an University,Xi'an,Shaanxi710054,China;Institute of Mineral Resources,Chinese Academy of Geological Sciences,Beijing100037,China)

机构地区：[1]中国地质科学院地质力学研究所,北京100081 [2]新构造运动与地质灾害重点实验室,北京100081 [3]中国科学院矿产资源研究重点实验室,中国科学院地质与地球物理研究所,北京100029 [4]东华理工大学地球科学学院,江西南昌330013 [5]中国地质调查局发展研究中心,北京100037 [6]长安大学地球科学与资源学院,陕西西安710054 [7]中国地质科学院矿产资源研究所,北京100037

出　　处：《现代地质》2021年第5期1251-1259,共9页Geoscience

基　　金：山东黄金矿业(玲珑)有限公司科研项目(LLYY-2019-001);中国地质调查局项目(121201081305);国土资源部科技发展计划项目(2002201);国家计委科技找矿项目(GJ9471110);国家科委基础研究特别支持项目(94-83);中国地质调查局项目(20023046);国家攀登项目(G1999043214,95-39(预)-6-3)。

摘　　要：构造体系由多方向、多应力-应变性质和多重次序的结构构造组成,这些结构面在构造应力场中有较为固定的分布型式。经过区域成矿带、矿田、矿床等不同层次地质研究,揭示了新华夏构造体系的共轭剪切、挤压和引张三种类型结构面,它们在平面上组成“米字型”构造。通过应力-应变有限元法模拟,将“米字型”构造分为三个形成阶段:第一期共轭构造阶段,发育NNW 345°方向(大义山式)张扭断裂和NEE 75°方向(泰山式)压扭构造;第二期挤压构造阶段,产生NNE 25°方向挤压断裂和褶皱;第三期横张构造阶段,产生NWW 300°方向(长江式)的横张断裂,给出了有利于控矿成矿的应力-应变场特征,为地质找矿指明了方向。三个阶段相比,构造带内主干拉应力以第一期NNW向构造带内为最大,第三期NWW向“长江式”构造带次之,第二期NNE向和第一期NEE向构造带内拉应力微弱,拉应力总体呈现出时间由老到新从最高下降至微弱之后再回升的趋势;最大主压应力从第一期NEE向构造带为中等,演进到第二期NNE向构造带为最大,第三期NWW向“长江式”构造带和NNW向构造带为最小,表现出时间由老到新,先增强至最高值再下降至最小的趋势。The structural system is composed of multi-directional,multi-stress-strain properties and different multi-order structures,which have relatively consistent distribution patterns in the stress field.Through geological study of regional metallogenic belts,orefields,and ore deposits,we reveal that the structural plane of the Neo-Cathaysian tectonic system includes three types,i.e.,conjugate shear,extrusion,and tensional,forming a double-cross pattern.Using the stress-strain finite element simulation method,the formation of three-stage double-cross pattern is analyzed:the stage-1 conjugate structure developed the NNW 345°(Dayishan-type)tension-torsion fault and NEE 75°(Taishan-type)compression-torsion structure;stage-2 extrusion structure developed the NNE 25°extrusion fracture and fold;stage-3 transverse-tension structure developed the NWW 300°(Yangtze-type)cross-tension fracture.This gives the stress-strain field characteristics favorable of ore control and provides direction for future geological prospecting.The main regional tensile stress is the largest in the stage-1 NNW-trending tectonic belt,followed by the stage-3 NWW-trending“Yangtze”tectonic belt,and then by the stage-2 NNE-trending and stage-1 NEE-trending tectonic belts.The main tensile stress decreases first from the highest to the lowest and then rises again.The maximum compressive stress of the three stages increases from the stage-1 NEE-trending tectonic belt to the largest in the stage-2 NNE-trending tectonic belt,and then decreases to the minimum in the NWW-trending“Yangtze”tectonic belt and the NNW-trending tectonic belt.This shows a trend that increases to the maximum compressive stress and then decreases to the minimum.

关 键 词：新华夏构造体系 “米字型”构造 有限元法模拟 应力应变分析 

分 类 号：P548[天文地球—构造地质学] P552[天文地球—地质学]