柴达木盆地及其南北缘前南华纪构造单元划分及地质演化

根据近几年来的综合研究和区调工作,对柴达木盆地及其南北缘前南华纪物质组成、变质变形等研究的基础上,首次按照不同地质构造演化阶段,将柴达木盆地及其南北缘前南华纪构造单元划分为:湟源中元古代古陆块、全吉新太古代—古元古代古陆块、达肯大坂古元古代古陆块、金水口古元古代古陆块、宁多中元古代古陆块5个一级构造单元以及8个二级构造单元,论述了各构造单元的地质特征,重塑了前南华纪地质阶段柴达木盆地及其南北缘地质过程与古陆块的演化历史。结合研究区内重要地质事件将柴达木盆地及其南北缘前南华纪地质演化厘定为新太古代古陆核形成、古元古代早期古陆块裂解、古元古代晚期—中元古代早期古陆块形成、中元古代早—中期陆内裂解沉降、中元古代晚期—新元古代早期陆块汇聚、新元古代陆块裂解6个地质过程,响应了全球Kenorland、Columbia、Rodinia三个超级大陆旋回事件。

Division and Geological Evolution of Pre-Nanhua Tectonic Units in Qaidam Basin and Its Northern and Southern Margins

Based on the comprehensive research and regional survey in recent years, we have studied the material composition, metamorphism and deformation of the Pre-Nanhua period in the Qaidam Basin and its northern and southern margins. Tectonic units in the Qaidam basin and its northern and southern margins are divided into five ancient land mass (i.e., Mesoproterozoic Huangyuan continental block, Neoarchean-Paleoproterozoic Quanji continental block, Paleoproterozoic Dakendaban continental block, Paleoproterozoic Jinshuikou continental block, and Mesoproterozoic Ningtuo continental block) and eight secondary structural units. The geological characteristics of each tectonic unit are discussed, and the geological process and evolution of the Qaidam Basin and its northern and southern margins in the pre-Nanhua geological stage are reconstructed. Compiling the key geological events in the region, tectonic evolution of the Qaidam basin and its northern and southern margin includes Neoarchean continental nuclei formation, Paleoproterozoic early rifting, the Late Paleoproterozoic-Mesoproterozoic ancient land mass formation, Early Neoproterozoic mid-stage intracontinental rifting, the Early Neoproterozoic continental convergence. Six Neoproterozoic continental riftings were in response to the global Kenorland, Columbia and Rodinia supercontinental cycle events.