Collaborative Research: RUI: Plio-Quaternary History of Basin Evolution, Climate Change, and Fold Growth in the Qaidam Basin-Investigating Wind-enhanced Climate-Tectonic Feedback

合作研究：RUI：柴达木盆地盆地演化、气候变化和褶皱生长的普里奥-第四纪历史——研究风增强的气候构造反馈

• 批准号: 1348075
• 负责人: Richard Heermance
• 金额: $ 18.76万
• 依托单位: The University Corporation, Northridge
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-04-01 至 2019-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1348075&HistoricalAwards=false
• 关键词: Collaborative; Research; RUI; Plio; Quaternary

The project aims to document acceleration in fold-growth due to increased wind erosion within the hyperarid western Qaidam Basin, China, and thus would provide the first example of wind-enhanced tectonics on Earth. In addition to understanding climate-tectonic feedbacks, this project will yield multiple high-resolution records of environmental change in the western Qaidam Basin across the late Pliocene climate crash and onset of Northern Hemisphere glaciations. This integrated, basin-scale dataset will provide evidence for desertification rates resulting from this climate shift, and may be useful as an analogue for comparable climate changes observed today. Moreover, the resultant new stratigraphic and structural datasets will be incorporated into a geoscience lab and made freely available via the Science Education Resource Center for educators across the country to use as a teaching tool. The project develops STEM workforce by training of graduate and undergraduate and the international collaboration provides an opportunity for international research experiences for those students. The project is supported by the Tectonics Program (Division of Earth Sciences) and International Science and Engineering (Office of International and Integrative Activities).Global climate changed to cooler, more arid conditions near the Plio-Pleistocene transition (3.6 to 2.6 Ma), causing environmental changes worldwide. In many regions, concurrent tectonic activity during this time period has evoked hypotheses of climate-tectonic feedbacks, but a causal relationship between observed depositional changes and local tectonics is difficult to quantify. One possible mechanism for climate-enhanced tectonics includes focused erosion across fold crests, or decreased overburden due to lake-level drop, both of which would enhance the isostatic response of uplift. This project, in collaboration with scientists from Lanzhou University (China) and Universite de Rennes (France), will test the hypothesis that climate change (manifested by enhanced aridity in central Asia) at about 3 Ma initiated episodic and spatially non-uniform wind erosion in the western Qaidam Basin in China, which in turn led to an acceleration and enhancement of fold growth. This research focuses on 8 stratigraphic sections spaced evenly throughout the Qaidam Basin and located on the flanks of active anticlines and involves: measurement of detailed sections; magnetostratigraphy; measurements of magnetic susceptibility, O and C stable isotopes; mapping of lithofacies, bed thickness, growth strata, and intraformational unconformities; and construction of 3-D structural models and palinspastic kinematic restorations of the folds. Data from each fold will be synthesized to test hypotheses that lake desiccation resulting from global climate aridification at about 3.0 Ma facilitated wind-erosion that enhanced fold growth on the basin floor; and that the western Qaidam Basin underwent alternating episodes of lake-level lowstands (and wind deflation) and lake-level highstands during Plio-Quaternary glacial and interglacial periods, respectively, in phase with the loess-paleosol successions of the Loess Plateau located to the east. The research project will provide basin-scale data on the relationship between aridification and deformation, allowing a test of whether wind erosion led to accelerated fold-growth.

该项目旨在记录由于中国Hyperarid Western Qaidam盆地内风侵蚀增加而导致的倍数增长，因此将提供地球上风增强构造的第一个例子。除了了解气候驻留反馈外，该项目还将产生在上新世气候崩溃和北半球冰川发作的西达姆盆地环境变化的多个高分辨率记录。这个综合的盆地规模数据集将提供证据证明由于这种气候转移而导致的荒漠化率，并且可以作为当今观察到的类似气候变化的模拟。此外，由此产生的新地层和结构数据集将纳入地球科学实验室，并在全国各地的教育工作者科学教育资源中心免费提供，以用作教学工具。该项目通过培训研究生和本科生来发展STEM劳动力，国际合作为这些学生提供了国际研究经验的机会。该项目得到了构造计划（地球科学系）和国际科学与工程（国际和综合活动的办公室）的支持。全球范围内的全球环境变化（3.6至2.6 MA）附近变为凉爽的，更干旱的条件，从而导致全球环境变化。在许多地区，在这段时间内并发构造活动引起了气候施加反馈的假设，但是观察到的沉积变化与局部构造学之间的因果关系很难进行量化。气候增强构造的一种可能机制包括跨褶皱的聚焦侵蚀，或者由于湖泊水平下降而减少了覆盖层，这两者都会增强隆起的等静力响应。该项目与兰州大学（中国）和雷恩大学（法国）的科学家合作，将检验以下假设，即在大约3 MA发起的情节和空间上，在中国西部Qaidam Basin的气候变化（表现为中亚的干旱增强）在中亚的启动时期和空间不均匀，这一质量是中国盆地的增长，这会导致增长和增长。这项研究的重点是整个基地室盆地均匀间隔的8个地层切片，位于主动抗管的侧面，涉及：详细切片的测量；磁层学；磁化率O和C稳定同位素的测量；岩相，床厚，生长层和内部不整合的映射；以及折叠的3-D结构模型和壁画运动的修复体的构建。将合成来自每个折叠的数据，以检验假设，即全球气候干旱在约3.0 mA的促进的风趋势中导致的湖泊干燥，从而增强了盆地地板上的褶皱生长；并且西部的基地亚河盆地分别与位于东部东部的Loess-Paleosol的后代相同，分别与位于东部的Loess-Paleosol的后代相同。该研究项目将提供有关干旱化和变形之间关系的盆地规模数据，从而测试风侵蚀是否导致褶皱增长。