地球表层系统对深部圈层时空演变的影响  

Surface system impact on the spatiotemporal evolution of deep Earth

作　　者：谢树成[1] 罗根明[1] 朱宗敏 Shucheng Xie;Genming Luo;Zongmin Zhu(State Key Laboratory of Biogeology and Environmental Geology,and School of Earth Science,China University of Geosciences,Wuhan 430074,China)

机构地区：[1]中国地质大学(武汉)生物地质与环境地质国家重点实验室,地球科学学院,武汉430074

出　　处：《科学通报》2024年第2期149-159,共11页Chinese Science Bulletin

基　　金：国家自然科学基金(42293290)资助。

摘　　要：地球系统科学研究的一个关键点是地球深部与表层系统的联动.深部过程通过火山作用对表层系统产生的重要影响已经取得了许多重要进展,认识比较薄弱的方面是表层系统如何影响深部的结构、过程和演化.板块俯冲将大量沉积物带入地幔过渡带乃至核幔边界的D″层,可以导致地幔的不均一性.特别是,板块俯冲带入的水通过影响地幔物理性质而增强地幔的熔融和对流能力,进而又在一定程度上影响了地球深部的岩浆活动、变质作用,以及包括板块俯冲在内的构造运动.华北克拉通破坏及其相伴的岩石圈变化被认为是水通过板块俯冲而影响深部过程的一个体现.表层系统不仅影响了深部的结构和过程,而且还极大地影响了深部的地质演化.在前寒武纪,古元古代和新元古代两次雪球地球之后形成了巨量的洋底沉积物,这些沉积物进入俯冲带后提高了板块俯冲的润滑性及其速率,进而对该时期活跃的全球构造运动及超大陆形成产生一些影响.在显生宙,4.3亿年以来陆地植物的大发展和2亿年以来海洋三大浮游生物的大发展都通过改变沉积物成分而影响深部圈层物质的演化,分别导致碎屑锆石和金伯利岩在一些同位素组成上出现重大转变.这些极少量但非常重要的新认识对人们研究行星地球的运行机制及其地质演化至关重要.表层物质进入地幔关键带如何进行循环和演化,水等表层物质是否改变了深部圈层的演化方向及规模,这些都是亟待解决的重大科学难题.而要突破这些难题,需要建立有效的定性和定量化的示踪技术方法体系.Interactions among the atmosphere,the hydrosphere,the biosphere and the lithosphere in Earth,are being paid great attention in geosciences due to the rapid disciplinary development of Earth system science in the world.One of the critical issues of understanding the dynamics to regulate Earth system is to decipher the interactions between the Earth surface system and the deep Earth,which in turn led to the co-evolution of all the subsystems of the whole Earth in geological history,finally providing the mankind with the habitable Earth.It is well known about the great impacts of deep processes,in particular volcanisms,on the surface system,while we know much less on the impacts of the surface system on the deep Earth via,in particular,the subduction of the tectonic plate.Subduction could transport a huge amount of sediments to the transitional zones of the mantle or even to the boundary between the mantle and the core,i.e.,the so-called D″layer at the bottom of the mantle;this causes,partly if not wholly,the heterogeneous distribution of the materials in the mantle.In particular,the addition of water into the deep Earth will greatly enhance the capacity of melting and the convention of the mantle materials,which in turn favors the deep processes including magmatism,metamorphisms,and plate tectonic movements.The destruction of the North China Craton and the associated variation of the lithosphere could be an important reflection of the water impact on deep Earth via the plate subduction.Some important biogenic elements,including carbon,oxygen,nitrogen,etc.,could also exert important impacts on the chemical composition of the deep Earth.In addition to the impact on the structure and processes of the deep Earth,the surface system will also exert impacts on the geological evolution of deep processes.Two enhanced lubrication events were recently proposed to occur on subductions in Early Proterozoic and late Proterozoic,respectively,due to the enhanced accumulation of oceanic sediments.These lubrication events identifi

关 键 词：地球生物学 地质微生物 深地科学 地球宜居性 行星地球 

分 类 号：P542[天文地球—构造地质学]