华南新元古代玄武质岩石成因与构造意义：从造山运动到陆内裂谷

华南广泛发育新元古代岩浆岩,深入了解这些新元古代岩浆岩的成因对研究区域大地构造及其在Rodinia超大陆的聚合一裂解演化中的作用有重要意义.目前学术界对这些岩浆岩的成因及其大地构造意义还存在很大的分歧.我们在系统分析华南新元古代玄武质岩石地球化学特征的基础上,通过对这些玄武质岩石的原始熔体成分和熔体温度,探讨其地幔源区的组成和热结构,为其形成的构造背景提供新的约束;结合近期发表的各种地质观察资料和玄武质岩石的研究结果,提出了华南晚中元古代.新元古代中期从造山运动到陆内裂谷的地球动力学演化的模型.

Petrogenesis and tectonic significance of Neoproterozoic basaltic rocks in South China:From orogenesis to intracontinental rifting

Neoproterozoic igneous rocks are widespread in South China.Understanding the nature and petrogenesis of these rocks has significant implications for the regional tectonic evolution and the assembly and break-up of the supercontinent Rodinia.However,there is still a hot debate on the petrogenesis and tectonic affiliations of these rocks.We carried out in this study a systematic compilation of geochemical data for the Neoproterozoic basaltic rocks in South China,and used these data to investigate their primary melt compositions,melting conditions and their mantle potential temperatures and compositions,with the aim of providing new constraints on their origin and petrotectonic associations.In combination with other aspects of geological observations,we proposed a geodynamic evolution model for the lithosphere of the South China Block involving late Mesoproterozoic-early Neoproterozoic orogenesis and middle Neoproterozoic intracontinental rifting.