板块驱动力:问题本源与本质

Driving Force of Plate Tectonics: Origin and Nature

本文回顾了板块构造理论之前和之后关于地球驱动力问题的发展历程,从近3000年人类由表及里认识地球的历史讨论中,可以发现人们认知这个问题的历史转变和外在干扰,并从唯物论?唯心论和固定论?活动论两条主线,梳理理解板块驱动力的问题本源和本质。当人们追究板块构造起源到前板块体制下的早期地球时,板块驱动力问题变成了对全时整体地球动力学问题的讨论,实质是对地球上块体变形和变位根本动因的追寻。随着视野逐渐开阔,人们必然回溯到最早期开尔文提出的热驱动,并通过对比太阳系其他行星,试图回答“为什么太阳系中唯独地球具有板块构造”这个根本问题。因此,地球变形和变位的一切根源和本质在于热的时空不均一性和不同阶段地球的热状态和热结构,然而,热驱动是重力作用衍生的次级机制。地球构造圈形变机制实际上在不断演变,重力驱动力的表现型式也在不断演变,具体地区和不同时空尺度又有所不同,因而就区域构造解析而言,驱动力是多起源的。最后,本文将板块驱动力问题拓展到地球系统动力学问题探讨,并就方法论、认知论做了简要总结。

This paper reviews the evolving history of main stream opinions regarding the Earth’s driving force before and after the appearance of plate tectonics theory.From the history of human being’s understanding of the Earth’s driving force,we can find out the historical changes and external influences concerning this issue,so as to understand the essence and nature of plate driving force based on two clues of Materialism-Idealism and Fixism-Activism.In investigations of the origin of plate tectonics and the pre-plate tectonic early Earth,the plate driving force becomes the focus of the global geodynamics,which is essentially the pursuit of the fundamental causes of the Earth’s deformation.Thermal drive was first proposed by Kelvin,and actually comparing other planets in the solar system may help us to answer the fundamental question of“why only the Earth in the solar system has plate tectonics”.Therefore,it is likely that the Earth’s deformation arises from the spatial and temporal heterogeneity of heat and the thermal states and structures of the Earth at different evolutionary stages,while the thermal drive is related to gravity.In fact,the deformation mechanism of the tectonosphere is evolving,whereas the driving forces are evolving and varying in specific areas and scales.Therefore,multiple driving forces should be considered in regional tectonic analysis.Finally,the issue of plate driving force should be discussed from the pointview of the Earth system dynamics,and this paper supplies a brief summary of methodology and epistemology.