Rift systems at continental margins: A case study of facies evolution and provenance of the sedimentary-volcanic facies evolution of the Permotriassic Mitu Group (Central Andes, Peru)

大陆边缘裂谷系统：二叠纪米图群（秘鲁安第斯山脉中部）相演化及沉积-火山相演化物源实例研究

• 批准号: 299483040
• 负责人: Professor Dr. Hans Heinrich Bahlburg
• 金额: --
• 依托单位: Institut für Mineralogie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/299483040?language=en
• 关键词: Rift; systems; continental; margins; case

The Permian-Jurassic Mitu Rift System in the Peruvian Andes marks the crucial transition from an accretionary (Neoproterozoic-Paleozoic) to the modern Andino-type continental margin, which exists since the Jurassic. Despite its geodynamic importance the Mitu Rift System is not well studied and understood. Consequently it remains unclear in which way basin structures, and the thicknesses and distribution of the basin fill have influenced Andean mountain building. Centered in the Urubamba valley near Cusco the proposed project combines a detailed analysis of volcanisedimentary facies with provenance analytical studies of single- and multi-grain heavy mineral samples including petrography, geochronology, geochemistry and isotope geochemistry. This will result, for the first time, in geographically resolved maximum depositional ages of different basin parts as well as the determination of variable inputs from different source areas. This will induce an enhanced temporal and spatial resolution of the units building the basin fill architecture. The combination of facies and provenance data will allow for deciphering temporal and spatial variations in the depositional development, and consequently of the basin itself. Finally, these data will constrain the influence of structures and sedimentary fill of the Mitu basin on mountain building of the Andean chain.

秘鲁安第斯山脉的二叠纪-侏罗纪米图裂谷系标志着从新元古代-古生代增生型大陆边缘向侏罗纪以来存在的现代安第斯型大陆边缘的重要转变。尽管它的地球动力学的重要性，米图裂谷系统没有得到很好的研究和了解。因此，尚不清楚盆地结构、盆地填充物的厚度和分布是如何影响安第斯山脉的形成的。拟议的项目以库斯科附近的乌鲁班巴山谷为中心，将详细分析火山沉积相与单颗粒和多颗粒重矿物样品的物源分析研究结合起来，包括岩相学、地质年代学、地球化学和同位素地球化学。这将导致，第一次，在地理上解决不同的盆地部分的最大沉积年龄，以及从不同的来源地区的可变输入的确定。这将导致增强的时间和空间分辨率的单位建设盆地填充架构。相和物源数据的结合将允许破译沉积发展的时间和空间变化，从而解释盆地本身。最后，这些数据将限制结构和沉积填充的米图盆地的安第斯山脉的山脉建设的影响。