关于板块运动启动时间的争论
The debate concerning the beginning of the plate tectonics
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摘要: 板块运动何时启动?是当前重大和争议较大的科学问题。文章从超大陆研究、板块运动的地质学标志和热动力学数据模拟等3方面的研究进展介绍国际地学界对这一问题的不同认识。在分析各种不同观点的基础上,作者阐述了对该问题的倾向性认识,赞同地球板块构造不是在一个特定时期出现的独立全球"事件",即不是一个等时的重大热-构造事件的认识。但从新太古代开始,地球上已出现具有板块水平运动特征的俯冲作用。由于地幔温度的差异,早期的板块运动缺少深俯冲形成的高压和超高压变质记录,而从新元古代开始,出现与现代板块一致的动力学机制。因此,赞同大致以新元古代作为"原板块样式"和"现代样式"板块运动的转换时间。Abstract: The problem"When did plate tectonics begin?"is one of highly controversial issues at present. In this paper, the different ideas concerning this problem are described on the basis of advanced involving supercontinent,geological criteria of plate tectonics and numerical models. The authors hold that plate tectonicis is not an independent event in the globe in a special period, i.e., it is not a major isochronic thermo-tectonic event. Meanwhile, subduction caused by plate tectonics with lateral movement have occurred since Neoarchean. Few high pressure and ultru-high pressure metamorphic rocks, however, in deep subduction belt occurred at the early stage of plate movement because of a higher mantle temperature. The authors agree with the opinion that the transitional period from proto-style to modern style plate tectonic roughly occurred around the Neoproterozoic.