Normal faulting, basin development, and paleoelevation in south Tibet and the evolution of the Tibetan Plateau

藏南正断裂、盆地发育、古海拔与青藏高原演化

• 批准号: 410123364
• 负责人: Professor Dr. Ralf Hetzel
• 金额: --
• 依托单位: Abteilung Sedimentologie und Umweltgeologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2023-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/410123364?language=en
• 关键词: Normal; faulting; basin; development; paleoelevation; Normal; faulting; basin; development; paleoelevation

The Tibetan-Himalayan orogen is the result of the ongoing plate convergence between India and Eurasia since the Early Cenozoic. At a late stage of this long-lasting history (i.e. since the mid- to late Miocene), the formation of several N-S trending rift systems dissecting the Tibetan Plateau highlights significant changes in the evolution of the orogen. The relation between the rifts in Tibet and the uplift of the plateau is the key to a better understanding of the geological evolution of the entire orogen. The joint Sino-German cooperation proposed here will focus on this major scientific problem by investigating the tectonic, sedimentological, and paleoelevation history of the Gyirong and Nima-Dingri Rifts, which extend over a distance of more than 300 km through the Lhasa terrane and into the Himalaya. The German group (this proposal) will apply low-temperature thermochronology (i.e. fission track and (U-Th)/He dating) on apatite and zircon along elevation profiles through granitic intrusions, which are exposed in the footwalls of the rift-bounding faults. Thermokinematic modelling of the respective data will allow us to quantify the onset of normal faulting and temporal variations in fault slip along strike of the Gyirong graben and the Nima-Dingri rift system. Our Chinese partners will use sedimentological and magnetostratigraphic analyses to reconstruct the evolution and the depositional environment of the fault-controlled Gyirong basin. On this basis, they will use stable isotope analysis of carbonate from paleosols, authigenic minerals, and fossils to decipher how the paleoelevation of the Gyirong basin has changed through time and how it is related to the activity of the basin-bounding faults. The complementary approaches and results of our two working groups will lead to an improved understanding of the causal relation between rift development, basin formation, and paleoelevation on the Tibetan Plateau and their timing with respect to past climate changes.

藏族 - 希马拉亚造山基因是自新生代早期以来印度和欧亚大陆之间正在进行的板块收敛的结果。在这段持久历史的后期（即自中新世中期至后期），形成了几种N-S趋势裂谷系统，解剖了藏族高原，突出了造影的演化的显着变化。西藏的裂痕与高原的隆起之间的关系是更好地理解整个造基地地质进化的关键。这里提出的联合中华人合作将通过研究Gyirong和Nima-Dingri Rifts的构造，沉积学和古升级历史，将重点放在这一主要科学问题上，该历史通过Lhasa Terrane和喜马拉雅山脉延伸了300公里以上的距离。德国组（此提案）将通过磷灰石和锆石沿高度概况通过花岗岩侵入物应用低温热量学（即裂变轨道和（u-th）/He约会），这些侵入物暴露在裂谷的脚壁上。相应数据的热动化建模将使我们能够量化正常断层和沿吉隆·格拉登（Gyirong Graben）和尼玛·丁格里（Nima-Dingri）裂rift系统的正常断层和时间变化的发作。我们的中国合作伙伴将使用沉积学和磁层学分析来重建断层控制的吉隆盆地的进化和沉积环境。在此基础上，他们将使用从古溶质，身份矿物质和化石对碳酸盐的稳定同位素分析来解密吉隆盆地的古硫化如何随着时间的流逝而变化，以及它与盆地结合断层的活性如何相关。我们两个工作组的补充方法和结果将导致人们对藏族高原上的裂谷发展，盆地形成和古升高之间的因果关系以及对过去气候变化的时机的了解。