下地壳填图理论与方法  

Theory and method of mapping the lower crust

作　　者：张旗[1] 翟明国[1,2] 魏春景[3] 焦守涛 周李岗 黄广宇 陈万峰 汤军[7] 刘睿 原杰 王振 王跃[11] 袁方林 ZHANG Qi;ZHAI Mingguo;WEI Chunjing;JIAO Shoutao;ZHOU Ligang;HUANG Guangyu;CHEN Wanfeng;TANG Jun;LIU Rui;YUAN Jie;WANG Zhen;WANG Yue;YUAN Fanglin(Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China;State Key Laboratory of Lithospheric Evolution,Beijing 100029,China;School of Earth and Space Sciences,Peking University,Beijing 100871,China;Natural Resources Comprehensive Survey Command Center,China Geological Survey,Beijing 100055,China;Technology Innovation Center of Geological Information,MNR,Beijing 100055,China;Key Laboratory of Mineral Resources in Western China(Gansu Province),School of Earth Sciences,Lanzhou University,Lanzhou730000,Gansu,China;School of Earth Sciences,Yangtze University,Wuhan 430100,China;School of Resources and Environmental Engineering,Shandong University of Technology,Zibo 255000,Shandong,China;School of Resources and Environment,Xingtai University,Xingtai 054001,Hebei,China;Institute of Geology,Chinese Academy of Geological Sciences,Beijing 100037,China;School of Earth Sciences and Resources,China University of Geosciences(Beijing),Beijing 100083,China)

机构地区：[1]中国科学院地质与地球物理研究所,北京100029 [2]岩石圈演化国家重点实验室,北京100029 [3]北京大学地球与空间科学学院,北京100871 [4]中国地质调查局自然资源综合调查指挥中心,北京100055 [5]自然资源部地质信息工程技术创新中心,北京100055 [6]兰州大学地质科学与矿产资源学院甘肃省西部矿产资源重点实验室,甘肃兰州730000 [7]长江大学地球科学学院,湖北武汉430100 [8]山东理工大学资源与环境工程学院,山东淄博255000 [9]邢台学院资源与环境学院,河北邢台054001 [10]中国地质科学院地质研究所,北京100037 [11]中国地质大学(北京)地球科学与资源学院,北京100083

出　　处：《地质通报》2024年第10期1673-1688,共16页Geological Bulletin of China

基　　金：自然资源部深地科学与探测技术实验室开放课题《下地壳底部填图理论与方法探索》(编号:Sinoprobe Lab 202211);中国地质调查局项目《地球科学数据集成与服务》(编号:DD20221785);邢台学院《邢台天梯山溶洞碳酸盐同位素记录的第四纪季风信息研究》(编号:XTXYYB202210)。

摘　　要：一个地区某个时段的下地壳是什么情况,很难了解清楚,究其原因是没有有效的方法手段。最近对花岗岩起源的研究表明,花岗岩来源于下地壳变质岩的部分熔融,与熔融残留相处于平衡,因此,可以根据地表花岗岩的特征反演下地壳变质岩的特征。变质岩研究的进展表明,可以根据不同温压条件构建不同组成变质岩的视剖面图,据此推测发生部分熔融时形成的熔体性质。这2个方面结合起来,即构成下地壳填图的理论基础,据此了解下地壳底部的情况,下地壳填图方法也由此而来。本文探讨了下地壳填图的方法,讨论目前下地壳地质图可能表达的图面内容,并着重讨论花岗岩可以给出的下地壳信息,提出对待争论问题的处理原则;讨论在没有花岗岩出露的情况下如何填图的问题,以及沉积、地层、古生物、矿产、构造等可能提供的下地壳信息,重点推荐镜质组反射率方法。此外,基于下地壳填图的意义及其局限性,以山西省早白垩世下地壳地质图作为实例,探讨了下地壳填图的作用和意义。The condition of the lower crust in a region at a certain time is a question that has not been considered by academia,for thereason that there is no means.Our recent research on the origin of granite shows that granite is derived from partial melting of lowercrust metamorphic rocks,and the granite is in equilibrium with the melt residual phase.Therefore,we can invert the characteristics ofmetamorphic rocks in the lower crust based on the characteristics of granite at the surface.On the other hand,the progress in theresearch of metamorphic rock indicate that it is possible to construct apparent profiles of metamorphic rocks of different compositionsaccording to different temperature and pressure conditions,and to infer the properties of the melts formed during partial melting.Thecombination of these two aspects forms the theoretical basis for the mapping of the lower crustal,based on which to understand theconditions at the bottom of the lower crust,and thus the mapping method of the lower crust is derived.This paper discusses the methodof mapping the lower crust,discusses the content of the lower crustal geological map that may be expressed in the current situation,focuses on the lower crustal information can be given by granite,and puts forward the principles for dealing with controversial issues.Italso discusses how to map the lower crust in the absence of granite outcropping,and the information of the lower crust that may beprovided by sedimentation,stratigraphy,paleontology,minerals,and structure are discussed,and the vitrinite reflectance method isrecommended.In addition,the significance and limitations of lower crustal mapping are also discussed.At last,we discussed thefunction and significance of lower crust mapping by taking the geological map of the lower crust in the Early Cretaceous of ShanxiProvince as an example.

关 键 词：下地壳地质图 填图方法 花岗岩 镜质组反射率 

分 类 号：P588.121[天文地球—岩石学] P62[天文地球—地质学]