试论“塔里木-扬子古大陆”再造

扬子古板块在地史演化中,是与塔里木板块靠近还是与华北古板块相近,这是中国大陆再造中长期争论的问题。在前人有限资料基础上,从岩石学、古气候学和古生物学等方面,论证扬子与塔里木古板块内部地质特征的可比性,从构造解析板块边缘造山带的岩石学记录,追踪扬子与塔里木古板块地史演化中的相关性,得出从新元古代至二叠纪扬子古板块多与塔里木古板块靠近,成为一个大陆,我们暂命名为“塔里木-扬子古大陆”。后经“峨眉地幔柱”的作用和“峨眉地裂运动”的拉张,古大陆解体,二板块分离,扬子古板块向东漂移到现今位置。二板块会聚和离散的演化模式若能成立,则涉及到中国一些基础地质科学的重新认识,也对预测大型矿产提供一点新思路。

Discussion on reconstruction of Tarim-Yangtze paleocontinent

Whether the Tarim plate or the North China plate were close to the Yangtze paleo-plate during its geodynamic evolution, and issues relating to the reconstruction of the Chinese continent have been debated for a long time. In this paper we demonstrate that the geological characteristics between the Yangtze and Tarim paleo-plates, based on petrology, paleoclimatology and paleontology research, are comparable. Tracing the correlation of geological history evolution between the Yangtze and Tarim paleo-plates, we conclude that the Yangtze paleo-plate was close to the Tarim paleo-plate from the Neoproterozoic to the Permian and that the Yangtze and the Tarim paleo-plates were part of one paleo-continent, named Tarim-Yangtze Paleocontinent. Owing to the action of “Emeishan mantle plume” and associated extensional tectonics, the Tarim-Yangtze paleocontinent was subjected to rifting. This caused the Yangtze Paleo-plate being moved to its present position. If this amalgamation and subsequent rifting model of the Tarim and Yangtze plates is valid, then a re-appraisal of Chinese geological history will be involved and will cast some light on forecasting for new mineral resources in China.