前板块构造与大陆起源研究进展及关键科学问题  

Research progresses and key scientific issues of pre-plate tectonics and origin of continents

作　　者：龙晓平 赵国春 翟明国[1,3] 郭敬辉[3] 初航[4] 彭澎 张少兵[5] 尹常青[6] Xiaoping Long;Guochun Zhao;Mingguo Zhai;Jinghui Guo;Hang Chu;Peng Peng;Shaobing Zhang;Changqing Yin(State Key Laboratory of Continental Dynamics,Department of Geology,Northwest University,Xi’an 710069,China;Department of Earth Sciences,The University of Hong Kong,Hong Kong,China;State Key Laboratory of Lithospheric Evolution,Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China;Tianjin Center,China Geological Survey,Tianjin 300170,China;CAS Key Laboratory of Crust-Mantle Materials and Environments,School of Earth and Space Sciences,University of Science and Technology of China,Hefei 230026,China;School of Earth Sciences and Engineering,Sun Yat-sen University,Zhuhai 510275,China)

机构地区：[1]西北大学地质学系,大陆动力学国家重点实验室,西安710069 [2]香港大学地球科学系,中国香港 [3]中国科学院地质与地球物理研究所,岩石圈国家重点实验室,北京100029 [4]中国地质调查局天津地质调查中心,天津300170 [5]中国科学技术大学地球和空间科学学院,中国科学院壳幔物质与环境重点实验室,合肥230026 [6]中山大学地球科学与工程学院,珠海510275

出　　处：《科学通报》2024年第12期1572-1585,共14页Chinese Science Bulletin

基　　金：国家自然科学基金(41890831)资助。

摘　　要：本文总结了现阶段前板块构造与大陆起源研究的三大重要进展:(1)提出了地幔柱构造、重力凹沉构造和热管构造的前板块构造模式;(2)揭示了非板块构造与板块构造的标志;(3)发现了地球早期层圈演化地质记录.但是,现有的前板块构造并不能完美解释太古宙大陆的起源,板块构造在解释大陆起源与演化方面也遇到重大挑战.此外,阐述了我国开展前板块构造与大陆起源研究的必要性、研究优势及风险,并凝练了目前前板块构造与大陆起源研究的关键科学问题:(1)地球是先有陆还是先有板块构造;(2)海陆的形成是否同步;(3)冥古宙陆壳和英云闪长岩-奥长花岗岩-花岗闪长岩(tonalite-trondhjemite-granodiorite,TTG)的起源.基于学科发展,提出动力学热模拟和比较行星学在前板块构造与大陆起源研究中的重要性.在此基础上,认为未来5~10年前板块构造与大陆起源的研究重点领域为:(1)大陆的起源及其对早期地球环境和生命的影响;(2)前板块构造样式及其形成机制;(3)太古宙的构造热体制及热演化;(4)前板块构造与类地行星演化.In the solar system,Earth is a unique planet with felsic continents,but controversy has long surrounded the issue of how felsic continents formed.At the center of the controversy is whether or not plate tectonics can be applied back to the Archean eon(>2.5 billion years)since most felsic continents were formed during Archean time,and if not,what was the main geodynamic mechanism that governed the formation and growth of felsic continents?In this review,we have summarized the current research progresses,the challenges,the key scientific questions,and the key research areas in the next 5−10 years.At present,there are three important achievements that have been obtained in this research field:(1)Three new models have been proposed for pre-plate tectonics,including mantle plume,sagduction,and heat pipe;(2)key identification criteria have been summarized to distinguish non-plate tectonics from plate tectonics;and(3)some geological records of early earth’s sphere evolution have been discovered.Main evidence supporting Archean plate tectonics are that(1)TTG(Tonalite-Trondhjemite-Granodiorite)rocks dominant in Archean terrains can also form in modern subduction zones;(2)Archean TTG rocks have arc-affinities in geochemistry;and(3)partial melting of mafic rocks to form Archean TTG requires H2O,which favours subduction zones.However,plate tectonics fails to interpret the following features of Archean cratons:(1)Dominant bimodal volcanic assemblages in the Archean greenstones;(2)Archean komatiites whose formation needed a melting process that occurred at 1600−1900°C;(3)nearly coeval emplacement of TTG plutons over a whole craton within a narrow time gap;(4)mass balance problems if Archean TTG rocks were derived from the 10%−30%partial melting of either eclogites or garnet amphibolites;and(5)dominant domiform structures with vertical lineations.Consequently,a number of pre-plate tectonic models have been proposed to interpret the origin of Archean felsic continents,including mantle plume,sagduction,and heat pipe mode

关 键 词：大陆起源 板块构造 前板块构造 比较行星学 动力学热模拟 

分 类 号：P542[天文地球—构造地质学]