Collaborative Research: Investigating Mesozoic Deformation in the Pamir: Implications for Crustal Thickening in the Pamir and the Evolution of the Tibetan Orogen

GSTDTAP

项目编号	1450899
	Collaborative Research: Investigating Mesozoic Deformation in the Pamir: Implications for Crustal Thickening in the Pamir and the Evolution of the Tibetan Orogen
	Alexander Robinson
主持机构	University of Houston
项目开始年	2015
	2015-02-01
项目结束日期	2018-01-31
资助机构	US-NSF
项目类别	Continuing grant
项目经费	76751(USD)
国家	美国
语种	英语
英文摘要	The objective of this proposal is to understand the timing and magnitude of Mesozoic crustal shortening that has occurred within the Central and Southern Pamir region as the western end of the Himalayan-Tibetan orogenic belt. The Himalayan-Tibetan orogen is the classic example of a mountain belt that has formed by continent-continent collision due to the convergence of the Indian and Eurasian tectonic plates. Conventional geologic understanding suggest that most of the uplift is occurred during the Cenozoic. In contrast, the principal investigators hypothesize that much of the crustal shortening and thickening recorded by rocks in this area occurred during Late Jurassic to middle Cretaceous time. To test this hypothesis, the PIs will conduct a multidisciplinary investigation that will involve geologic and structural mapping, stratigraphic analysis, geochronologic and and thermochronologic dating. The results of this project will provide new insights in to the understanding of the tectonic evolution of the Pamir region of the Himalayan-Tibetan orogenic belt. In addition to the scientific goals of the research, the project is contributing to the training of graduate and undergraduate students in cutting-edge research in the geosciences, an important STEM discipline. The project will contribute to the broadening of participation of underrepresented groups in the geosciences, which is an important societal outcome. The project will facilitate international collaboration between researchers at U.S., Italy, and Tajikistan, and will build important institutional collaborations between two U.S. universities. The project will include outreach efforts that include lectures and workshops on the Geology of the Pamir for students at the University of Dushanbe in order to promote geoscience education and science literacy in this developing country. The outcomes of the research will be published in peer-reviewed scientific literature and presentations at professional society meetings; isotopic and geochemical data will be archived in web-based community databases. Over the last decade, increased evidence has shown that much of the crustal shortening and thickening in the Tibetan plateau is Cretaceous in age, pre-dating the Cenozoic collision between India and Asia. However, it is still unclear how laterally extensive, or spatially variable, pre-Cenozoic shortening and thickening is across the entire orogen. This study will provide important information on the timing and magnitude of crustal shortening over a broad region of the western portion of the Tibetan orogen and address important questions regarding the along-strike continuity of pre-Cenozoic deformation in the Tibetan orogen. Further, while significant Cenozoic crustal thickening in the Pamir has been documented in Miocene to Recent gneiss domes, early calculations of the magnitude of upper crustal shortening have been shown to be significantly overestimated, raising important questions regarding the mechanism of Cenozoic crustal thickening (i.e. underthrusting vs. pure shear thickening). The results of this will also provide new information in understanding the mechanisms of crustal thickening in the Pamir region. The specific goal of this study involves testing the hypothesis that much of the crustal shortening and thickening in the Central and Southern Pamir is Mesozoic in age (rather than Cenozoic, as previously interpreted) and represents the along-strike continuation of extensive Late Jurassic-middle Cretaceous crustal shortening and thickening documented in Tibet. The project will include detailed geologic mapping and structural analysis to evaluate crustal shortening in the Pamir; stratigraphic analyses of coarse terrigenous deposits found throughout the region to evaluate whether the deposits are syntectonic with regional shortening structures; geochronologic (detrital U-Pb zircon) and thermochronologic (detrital muscovite 40Ar/39Ar dating, and detrital AFT/AHe double dating) analyses of coarse terrigenous deposits to determine the age of deposition in order to evaluate timing of regional shortening; thermochronologic analyses of basement terranes involved in regional shortening to evaluate timing of shortening related exhumation.
来源学科分类	Geosciences - Earth Sciences
文献类型	项目
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/67533
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	Alexander Robinson.Collaborative Research: Investigating Mesozoic Deformation in the Pamir: Implications for Crustal Thickening in the Pamir and the Evolution of the Tibetan Orogen.2015.