Early Tertiary orogenic evolution of the southern Central Andes as reflected by the detrital record preserved in the Puna Plateau and Eastern Cordillera of NW Argentina

阿根廷西北部普纳高原和东科迪勒拉山脉保存的碎屑记录反映了中安第斯山脉南部的早第三纪造山演化

• 批准号: 28054419
• 负责人: Professor Dr. Manfred Strecker, Ph.D., since 8/2007
• 金额: --
• 依托单位: Department of Geosciences
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2006
• 资助国家: 德国
• 起止时间: 2005-12-31 至 2008-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/28054419?language=en
• 关键词: Early; Tertiary; orogenic; evolution; southern

One of the key scientific problems in Geosciences today is centred on the relationships between processes acting in the deep earth (lithosphere) versus processes acting at shallower levels (in the crust) and at the surface. It is not clear if or how such processes are acting together and whether or not a coupling exists. Understanding the relationships between deep Earth and surficial processes is of fundamental importance if we want to understand Earth dynamics. Mountain belts and related foreland basins are the result of this complex interaction and provide a natural laboratory to investigate the relationships between endogenic and exogenic forces. A foreland basin system is genetically linked to its adjacent mountain belt and provides unique, long-term archives of information about deep Earth processes (subsidence) and surficial processes (sediment deposition and weathering). The magnitude of subsidence, the shape of the sedimentary fill and the source of detrital sediments in foreland basins depends on the location and size of the topographic load, the mode of compressional stresses acting during sedimentation and on the type, relief and climate of the source-basin system. Sedimentary basins preserved within the Puna Plateau and Eastern Cordillera in NW Argentina provide one of the earliest records of compressional deformation associated with Andean mountain building. These basins contain >4 km-thick Paleogene clastic sediments that are exceptionally well exposed. Studies in contemporary sedimentary basins in southern central Bolivia (Altiplano) lead to the proposition that a foreland basin system, i.e. contractional deformation, already started in the Paleocene and that a significant amount of foreland lithosphere was thrusted underneath the Andean crust leading to the building of the orogenic belt. A multidisciplinary study of time equivalent basins in NW Argentina shall provide new data that will allow testing and potential validation of this model. This in turn will permit quantification of source paleogeography, exhumation, relief, climate and mechanisms of basin formation in this part of the Andes, in a key time that is the Paleogene, contributing greatly to our understanding of mountain building associated to the Puna-Altiplano Plateau and Eastern Cordillera system in the early Tertiary.

当今地球科学中的一个关键科学问题集中在作用于地球深部（岩石圈）的过程与作用于较浅层次（地壳）和地表的过程之间的关系。目前尚不清楚这些进程是否或如何共同作用，以及是否存在耦合。如果我们想了解地球动力学，了解地球深部和表面过程之间的关系是至关重要的。山区带和相关的前陆盆地是这种复杂相互作用的结果，并提供了一个天然的实验室，研究内生和外源力量之间的关系。前陆盆地系统在遗传上与其邻近的山区带相联系，并提供有关地球深部过程（沉降）和地表过程（沉积物沉积和风化）的独特的长期信息档案。前陆盆地的沉降幅度、沉积充填物的形状和碎屑沉积物的来源取决于地形载荷的位置和大小、沉积过程中挤压应力的作用方式以及源盆系统的类型、地形和气候。阿根廷西北部普纳高原和东科迪勒拉山脉内保存的沉积盆地提供了与安第斯山脉造山运动有关的挤压变形的最早记录之一。这些盆地含有厚度大于4 km的古近系碎屑沉积物，这些沉积物非常好地暴露。对玻利维亚中南部（阿尔蒂普拉诺）当代沉积盆地的研究表明，前陆盆地系统，即收缩变形，早在古新世就已开始，大量的前陆岩石圈被冲到安第斯地壳之下，导致造山带的形成。在阿根廷西北部的时间等效盆地的多学科研究应提供新的数据，将允许测试和潜在的验证这个模型。这反过来又将允许量化的源古地理，剥露，救济，气候和盆地形成机制的安第斯山脉的这一部分，在一个关键的时间，即古近纪，极大地促进了我们的理解与普纳高原和东科迪勒拉系统在第三纪早期的造山运动。