再论“关于板块运动启动时间的争论”

Re-discussion on "The debate concerning the beginning of the plate tectonics"

笔者在"关于板块运动启动时间的争论"一文(陆松年等,2016)基础上,参阅公开发表的部分文章,介绍了前板块岩浆洋和停滞盖研究的新进展,并再次讨论有关板块运动启动时间的不同认识和观点。根据太阳系30个类地行星天体图像资料,硅酸盐质行星体在它的生命期由于冷却和岩石圈增厚似乎经历过多种构造样式,包括岩浆洋、多类型停滞盖以及板块构造。硅酸盐类行星由于增生、分异、撞击和放射性活动,使星体变热,发生熔融反应而形成"岩浆洋"。硅酸盐星球体早期很可能是大面积但寿命很短的岩浆洋,之后的星球可能受两种构造模型控制:停滞盖构造和板块构造。已有资料表明,停滞盖构造是类地行星的主要构造类型,而板块构造在类地行星中是十分罕见的。停滞盖构造是一个单一的、围绕天体的板块,基本由硅酸盐质岩石圈组成。停滞盖构造有三种主要变化形态——热管、滴状及柱状体、拆沉及上涌流。板块构造启动时间从>4.4Ga到0.85Ga至少有11种不同观点:认为板块构造始于冥古宙的有1种、始于始-古太古代的有3种、始于中-新太古代的有4种、始于古元古代有1种、始于新元古代的有2种。本文重点介绍了地球冥古宙-太古宙板块运动启动的地质学证据和特点。

On the basis of a former paper"The debate concerning the beginning of the plate tectonics"by Lu et al.(2016),and referring to some newly published articles,the authors introduce the new progress in the study of the magma ocean and stagnation lid of the front plate,and discuss the different understandings and viewpoints about the starting time of plate tectonics once again.According to the image data of 30 planetoids celestial bodies in the solar system,the silicate planetoids body seems to have experienced several structural patterns during its life cycle due to cooling and thickening of the lithosphere.These tectonic styles include magmatic ocean,various types of stagnant lid,and plate tectonics.Silicate planetoids heat up and melt to form a"magmatic ocean"due to accretion,differentiation,impact and radioactive activity.A large enough silicate body is likely to have a short-lived magma ocean.After the magma ocean stage,the silicate planetoids may have two tectonic models:the stagnant lid and plate tectonics.It has been shown that the main tectonic type of planetoids is the stagnant lid structure,while the plate tectonic is very rare in planetoids.The stagnant lid structure is a single plate surrounding celestial bodies,which is basically composed of silicate lithosphere.There are three main changing forms of a stagnant lid,including heat-pipe,drips and plumes,and delamination and upwelling.There are at least 11 different viewpoints that the plate tectonics began to operate in the history of the earth from>4.4Ga to 0.85Ga.It is considered that there is 1 species of plate tectonics that began in the Hadean,3 species in the Eo-Paleo Archean,4 species in the Meso-Neo Archean,1 species in the Paleoproterozoic and 2 species in the Neoproterozoic.This paper mainly focuses on the geological evidence and characteristics of the initiation of the Hadean and Archean plate tectonics.