中文摘要：

早期地球（early Earth）是指冥古宙（或称dark ages,黑暗时代）的地球,也称为＂Hadean Earth＂,即是45.6亿年至40亿年的地球。早期地球是地球科学研究的前沿,是诸多地质、地球化学理论或模型必须面对的基本科学问题。本文系统综合了与早期地球相关的研究进展,特别是近10年来的进展,以建立地质理论的各种大地质现象起源为主线,包括原始地核、原始地壳、地幔对流、岩石圈、地幔不均一性、陆壳和洋壳、水及大气圈和海洋、板块构造、早期生命等起源问题。这些都是地球科学的重大前沿科学问题,也与地球物质起源相关的宇宙起源、元素起源密切相关。原始地核出现最早,在原始地球形成之初的几个百万年内就形成了,4 450 Ma地球发生了最后一次全球整体的大规模熔融事件,地球的原始地幔和原始地核再次均一化,原始地核可能消失;4 450 Ma之后的地核大小与现今的地核大小基本一致,只是液态外核在不断冷却缩小,而固态内核在不断增大;从锆石年龄得出最早地壳大于4 408Ma,而从Sm-Nd体系获得的最早地壳年龄为4 470 Ma,比后期地核形成要早。总之,原始地壳从原始地幔中分离出来的时间大体为44.5亿年。一些最老的锆石中Nd、Hf的地球化学特征也证明原始地幔分异发生在43亿年前。岩浆抽吸后的原始地幔上部经冷却,原则上可能构成原始地壳下部的原始岩石圈地幔,从而开始出现上地幔和下地幔的分异演化。但是,地球40亿年前的原始岩石圈没有大洋岩石圈和大陆岩石圈之分。对地幔对流循环起源有3种认识,最可能产生于44.5亿年前的偶然撞击事件。地幔不均一性起源可能与地幔对流循环有关,可用地幔柱理论或地幔翻转过程给予解释,且早于板块构造体制起源,板块构造增强了其不均一性。水、大气圈和海洋的起源早于陆壳和洋壳的分异。最早的水最可靠的直

英文摘要：

The early Earth refers to the Hadean or dark ages of the Earth.The Hadean Earth is also known as the Earth of 4.56 to 4Ga.The early Earth is a scientific frontier of Earth Science and a basic problem related to many theories on geology and geochemistry.This paper systematically integrates the early Earth-related research advances,especially in the recent 10 years,from the professional popularization perspective.Focusing on the origins of large geological phenomena in the establishment of geological theory as the main line,this paper describes concisely the origins of the proto-Earth core,proto-crust,mantle convection,lithosphere,mantle heterogeneity,continental and oceanic crusts,water and atmosphere and oceans,plate tectonics,the origin of early life and others that are major frontier scientific issues of Earth Science.These problems are closely associated with some origins of the universe and elements related to origin of matter in the Earth.The proto-core of the Earth occurred after a few million years at the beginning of the formation of the Proto-Earth;the last time global large-scale melting event in the Earth happened at 4450 Ma;the Earth＇s proto-mantle and proto-core was again under homogenization;and the proto-core may disappear.After 4450 Ma,the primitive core size is similar to the size of the present core.Only the liquid outer core was under cooling and its size decreased,while the solid inner core increased.Based on the earliest crustal zircon ages that are greater than4408 Ma,and the earliest crustal age obtained from the Sm-Nd system is 4470Ma;the formation of the crust is earlier than that of the late core.Therefore,the time of the proto-crust separated from the proto-mantle is about 4.45 Ga.Based on the geochemical characteristics of Hf and Nd,some of the oldest zircons occurred at4.3Ga ago.The upper part of the primitive-mantle after assimilation of the magma was cooled,which may constitute the primitive lithospheric mantle that can become the lower part of the proto-crust.However,there is no