Collaborative Research: Climatic and Tectonic Controls on Sedimentation and Incision in the Marginal Basins of the Southern Puna Plateau

合作研究：气候和构造对普纳高原南部边缘盆地沉积和切割的控制

• 批准号: 0635630
• 负责人: Barbara Carrapa
• 金额: $ 13.82万
• 依托单位: University of Wyoming
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-06-01 至 2010-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0635630&HistoricalAwards=false
• 关键词: Collaborative; Research; Climatic; Tectonic; Controls

An increase in accumulation rates and a coarsening of clastic material has been observed all around the world in Late Pliocene and Quaternary time, and has been used to infer an increase in erosion rates. This global signal has been attributed to climate change, particularly to lowered sea-level, glacial expansion and increased climatic oscillation. However, in many cases this increase in erosion rate may be overstated due to re-deposition and compaction of older material, and a lack of well-studied, well-dated sites. Local structural deformation and tectonic uplift may adequately explain cases in which in increase in sedimentation rates in Plio-Quaternary time is truly observed. The marginal basins of the Puna Plateau in northwestern Argentina are an ideal natural laboratory in which to translate the information contained in the detrital, structural and geomorphic records into an understanding of the relative roles of tectonics and climate. This project aims to test the climate versus tectonics hypothesis by dating the timing of deposition of the Pliocene conglomerates, determining the provenance of the conglomerates, constraining the source region(s) exhumation and erosion history, and investigating the recent tectonic and geomorphological history of the basins. Correlations between source erosion, sedimentation and subsequent basin incision will be made with existing climatic and tectonic data to assess whether or not a genetic link exists between climate and/or tectonics and sedimentation and incision along the Puna Plateau. The effect of climate versus tectonics on erosion and sedimentation is an ongoing debate. It has been proposed that global climate change triggered an apparent worldwide increase in erosion and sedimentation rates in the last 3.6 million years ago (Pliocene time). The goal of this study is to contribute to this debate by discriminating and constraining different processes responsible for the deposition of Pliocene conglomerates along the margin of the Puna Plateau, northwestern in Argentina. The plateau is part of the Puna-Altiplano plateau in South America, the second largest plateau on Earth. This project will lead to new results that will be able not only to inform the climate versus tectonics debate but will also elucidate the effects of tectonic and surface processes in the creation and preservation of the sedimentary rock record along continental plateaus in general.

在上新世和第四纪晚期，世界各地都观察到了累积速率和碎屑材料的提高，并已被用来推断侵蚀率的增加。该全球信号归因于气候变化，尤其是降低了海平面，冰川膨胀和气候振荡的增加。但是，在许多情况下，由于较旧材料的重新沉积和压实以及缺乏良好的，良好的地点，侵蚀率的增加可能会被夸大。局部结构变形和构造隆起可以充分解释案例，其中真正观察到PLIO期间时间的沉积率增加。阿根廷西北部Puna高原的边缘盆地是一个理想的自然实验室，可以将碎屑，结构和地貌记录中包含的信息转化为对构造和气候相对作用的理解。该项目的目的是通过与上世代集团沉积的日期来测试气候与构造假说，确定砾岩的来源，限制源泉的源区域和侵蚀历史，并研究盆地的近期构造和地貌历史。源侵蚀，沉积和随后的盆地切口之间的相关性将与现有气候和构造数据之间建立，以评估Puna高原沿线的气候和/或构造和沉积和切口之间是否存在遗传联系。气候与构造对侵蚀和沉积的影响是一场持续的辩论。有人提出，在过去的360万年前（上新世时代），全球气候变化引发了全球侵蚀和沉积率的明显增加。这项研究的目的是通过区分和限制导致在阿根廷西北部Puna Plateau的边缘沉积的不同过程来为这场辩论做出贡献。高原是南美位于地球上第二大高原的Puna-Altiplano高原的一部分。该项目将导致新的结果，不仅能够告知气候与构造辩论，还将阐明构造和表面过程在总体上沿大陆高原沿大陆岩石记录的创建和保存中的影响。