对中国东部中生代动力学机制的新认识

从20世纪70年代板块构造学说引入中国后，中国地质学家(包括笔者)普遍接受了太平洋板块向欧亚板块俯冲导致中国东部中生代强烈的构造-岩浆活动和相应的成矿作用的观点，乃至成为被认知的理论至今仍然广泛流传。但是，2000—2006年国土资源部开展的《中国岩石圈三维结构》专项研究成果表明：深部软流圈(层)物质上涌才是中国东部中—新生代强烈构造-岩浆活动的主要动力来源。在进一步研究中国东部巨厚的软流圈形成的原因时发现：中侏罗世以来，中国大陆受到了来自4个不同方向的动力挤压，由此导致软流圈物质汇聚到中国东部及邻区大陆之下。太平洋板块的俯冲力只是4个方向中的一个——由东向西挤压，它起到了阻挡软流圈物质继续向东部“洋区”流动的作用，可称它为“远程力效应”。

A tentative discussion and new recognition of Mesozoic geodynamic mechanism in eastern China

Since the theory of plates was introduced into China in the 1970's，the viewpoint that Mesozoic strong tectonomagmatic activities and mineralization in eastern China were caused by the subduction of Pacific plate towards Eurasia plate was widely accepted by China's geologists including the authors. The results of the project "Three-Dimensional Structure of the Lithosphere in China" supported by the Ministry of Land and Resources show that the upwelling of asthenospheric matter was the main dynamic source of Mesozoic strong tectonomagmatic activity and mineralization in eastern China. The authors have found that the asthenospheric matter converged beneath the eastern China and adjacent areas by extrusion force from four directions which affected China's continent since the Middle Jurassic. The subduction of Pacific plate was only one of the causations. The effect of Pacific plate that obstructed the eastward migration of the asthenospheric matter is called the long-distance force effect by the authors.