Collaborative Research: Dating Deformation with Titanite

GSTDTAP

项目编号	1928377
	Collaborative Research: Dating Deformation with Titanite
	George Gehrels (Principal Investigator)
主持机构	University of Arizona
项目开始年	2019
	2019-07-15
项目结束日期	2021-06-30
资助机构	US-NSF
项目类别	Standard Grant
项目经费	115621(USD)
国家	美国
语种	英语
英文摘要	Much of our understanding of the geologic history of the Earth comes from radiometric dating of Earth processes. Currently, Earth scientists have a difficult time placing narrow constraints on the precise time that a fault occurs deep within the crust of the Earth. This project combines two state-of-the-science techniques to directly date the time of faulting along a key fault zone in southeast Alaska, and thereby date when ancient earthquakes occurred. Development of this new analytical technique will enable considerable future research and understanding of how Earth materials deform. In addition, this research project will provide training and research opportunities for a female graduate student and several undergraduate students. Visits to local elementary schools will enable potential future scientists to experience the methods and results of Earth science research, with direct implications for earthquake hazards. This collaborative project consists of two principal objectives: 1) develop the mineral titanite as a tool for dating high-temperature deformation by a combined microstructural and microgeochronology approach, and 2) apply this tool to the evolution of the spectacular Coast Shear Zone and Great Tonalite Sill in the Coast Mountains orogen of southeast Alaska. Research methods will incorporate a field study to understand qualitatively the evolution of a mid- to deep crustal intra-arc shear zone and synkinematic sheeted-sill complex exposed in the Coast shear zone of Alaska and Canada. Titanite analyses will include electron-backscatter diffraction maps of titanite microstructure, and laser-ablation split-stream inductively coupled plasma maps of titanite composition that incorporate U-Pb dates. These data will allow assessment of the physical and chemical processes that affected the crystal, and the identification of crystals whose U-Pb distribution reflects high-temperature deformation. Because titanite is a widespread crustal mineral, this technique should have broad application globally and enhance our understanding of how crust deforms and orogens assemble and change through time. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
文献类型	项目
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/214131
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	George Gehrels .Collaborative Research: Dating Deformation with Titanite.2019.