摘要
在简要介绍2012年全球地质年代表(GTS2012)有关前寒武纪年代地层划分新方案的核心内容基础上,评述了新方案以全球关键事件为基础的"自然主义年表"特点及其合理性,探讨其在全球界线层型(GSSP,‘金钉子’)研究及中元古代划分方案上存在的可能缺陷与问题。认为GTS2012新方案其实为中国学者在未来国际前寒武纪、特别是中元古代年代地层学研究等,提供了新的挑战和机会。在厘定华北和扬子地块中元古代年代地层格架基础上,结合该时期地幔羽-大火成岩省及超大陆演化等研究,尝试提出新的中国及全球中元古代年代地层划分参考方案。同时笔者建议,当前阶段中国学者可参照GTS2012有关前寒武纪全球界线层型研究的基本原则和流程,通过积极开展相关地层的高分辨测年及稳定同位素漂移等综合研究,确认上述地幔羽-大火成岩省事件的沉积记录,并建立起区域性的中国中元古界各"系(纪)"底界界线层型。这将在促进中国中元古代地层学研究的同时,为未来中国学者在全球前寒武纪、特别是中元古代年代地层划分等相关研究领域赢得更多话语权。
With a brief introduction about the core of the newly proposed scheme for me revised Precambrian time scale in The Geological Time Scale 2012 （GTS2012）, in which a series of linked causative global key- events has been suggested as the definition of the Global Boundary Stratotype Sections and Points （GSSPs, the so-called ＇Golden Spike＇） of the base of the revised and re-named Precambrian chronostratigraphie units, both the specific viewpoints of the ＇naturalistic-time-scale＇ and the justification of this proposal have been reviewed. In addition, some implicit imperfections and problems regarding both the establishment of the Precambrian GSSPs and the inner-subdivision of the Mesoproterozoic Era, which only one - 1. 0 Ga-lived ＇Rodinian＇ Period/System in this Era were proposed, have been highlighted. Due to this obvious need for updating, it could be considered that the proposed Precambrian time scale of the GTS2012 would be a new challenge and unique opportunity for Chinese researchers. Combining the possible Mesoproterozoic mantel-plume/Large Igneous Provinces （LIPs） events and the supercontinent evolution, as well as the revision of the regional Mesoproterozoic chronostratigraphic framework both at the North China Craton and the Yangtze Craton, a referential quadripartite （four Periods/Systems） Mesoproterozoic subdivision of China and the corresponding international chart has been proposed. Moreover, it could be suggested that during the current stage, Chinese researchers may positively manage to develop some comprehensive researches focusing mainly on the determination of the possible regional stratotype section and points （RSSP） of each regional System （Period） of the Mesoproterozoic Era of China. It would include the high-resolution age-dating calibration and the stable isotopic excursion analyses to identify the possible coupling signals of the mantel-plume/LIPs mentione＆ above, which would follow the proposed primary principles and procedure of the Precambrian GSSP research in the GTS2012. Consequently, it would be significantly beneficial for Chinese researchers seeking more discourse power in the future on the global Precambrian research, especially the Mesoproterozoic chronostratigraphy and other related fields, while also promoting the relevant studies of China.
出处
《地学前缘》
EI
CAS
CSCD
北大核心
2014年第2期119-138,共20页
Earth Science Frontiers
基金
国家自然科学基金项目(40772076
41272046)
国家重点基础研究发展计划"973"项目(2011CB808800)
