Deciphering the Role of Deformation in Orogenic Evolution Through Multi-scale Structural Studies in a "Crustal Laboratory", Central Sierra Nevada, California

GSTDTAP

项目编号	1524798
	Deciphering the Role of Deformation in Orogenic Evolution Through Multi-scale Structural Studies in a "Crustal Laboratory", Central Sierra Nevada, California
	Scott Paterson
主持机构	University of Southern California
项目开始年	2015
	2015-08-15
项目结束日期	2018-07-31
资助机构	US-NSF
项目类别	Continuing grant
项目经费	90836(USD)
国家	美国
语种	英语
英文摘要	This project focuses on a multiscale investigation aimed at understanding deformation processes associated with the development of the central Sierra Nevada mountain range. The project involves geologic mapping and measurement of deformation fabrics and the building of a data bases that records deformation fabric, strain measurements. The fieldwork and digital database will be used to better understand processes that contribute to the localization of deformation in mountain belts during orogenic events. In addition to the scientific objectives of the study, the project is contributing to socially and nationally relevant goals, including the training of graduate and undergraduate students in an important STEM (Science, Technology, Engineering and Mathematics) discipline; development of a digital data base in a geographic information system (GIS) format that will be made available to the scientific community and the public; development of an extensive, integrated digital field guide to the geology of the region that can be used for teaching and research; and the development of virtual field trips that will be publically available. Undergraduate student training will involve participation in the university's UTR program, a multidisciplinary, learner-centered research experience that includes field studies followed by lab research, culminating in professional publications and presentations. Efforts will be made in this program to broaden the participation of underrepresented groups in the geosciences. The project involves international collaboration with a scientist from Canada, and the project will contribute to research infrastructure at the host institution. Results of the research will be made available through peer-reviewed publications in the scientific literature, presentations at professional society meetings, and public outreach through lectures at schools and national parks. Samples will be archived at the university, and digital data will be made available via university servers and community databases. In addition, all data will be shared with Yosemite National Park and other conservation area personnel. Rheological heterogeneity in orogens over the range of lithospheric observation scales leads to deformation partitioning of tectonic boundary conditions throughout intervening scales, making it unrealistic to apply single-scale models to connect small-scale structures to tectonic scale processes and boundary conditions. The proposed research is a multi-scale investigation aimed at connecting deformation processes, tectonics, and orogenic evolution using a state of the art, self consistent Multi-Order Power-Law Approach (MOPLA) which incorporates multi-scale deformation in its formulation and provides a rigorous means for bridging small-scale studies to tectonic-scale deformation conditions and processes. The relationship of tectonics to orogenic evolution and the resulting multi-scale deformation will be investigated by applying MOPLA to the data rich central Sierra Nevada where extensive multi-scale structural, strain, and petrological data linked to mapping and geochronology have been collected over several decades. These define an apparent Mesozoic history of episodic deformation, plate motions, and tectonic regimes that parallel episodic magmatism. A geographic information system (GIS)-based synthesis of new and existing datasets will be created and then integrated with MOPLA to construct and test multi-scale modeling predictions. This work will test the hypothesis that intra-orogenic deformation is partly controlled by evolving deformation partitioning that is further modulated by the thermal effects and volume addition related to episodic magmatism. This will be investigated through modeling to test four corollary, interrelated hypotheses: (1) Structural variations observed in the central Sierra Nevada at all scales often arise from time-dependent deformation partitioning rather than shifting plate motions. (2) Magmatic fabric orientations in central Sierra Nevada plutons represent local fabrics developed in partitioned flow fields rather than distinct increments of the bulk deformation field. (3) Episodic deformation is primarily driven by the effects of episodic magmatism. (4) Intra-orogenic bulk shortening is accommodated primarily by crustal thickening along broad, low strain domains rather than motion along localized, high strain zones. As single scale structural studies and plate motion reconstructions for older orogens are limited, forward modeling of multi-scale deformation will lead to a better understanding of how to integrate local observations to explore their regional significance.
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/68466
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	Scott Paterson.Deciphering the Role of Deformation in Orogenic Evolution Through Multi-scale Structural Studies in a "Crustal Laboratory", Central Sierra Nevada, California.2015.