Laramide Relamination of Mantle Lithosphere Beneath the Colorado Plateau: A Xenolith Study

GSTDTAP

项目编号	1524768
	Laramide Relamination of Mantle Lithosphere Beneath the Colorado Plateau: A Xenolith Study
	Alan Chapman
主持机构	Macalester College
项目开始年	2015
	2015-10-01
项目结束日期	2017-09-30
资助机构	US-NSF
项目类别	Continuing grant
项目经费	90298(USD)
国家	美国
语种	英语
英文摘要	This award will provide support for the career development of a junior investigator in the area of Earth Sciences. The study will foster new collaborations and enhance old partnerships with scientists at the University of Arizona and Rice University. This project will constitute the intellectual basis and support the training for three undergraduate students. A classroom- and field-based outreach program, through University of Arizona Extension and intended for students in grades 6-8, will be integrated with this research. Course materials produced through this program will be shared with the geosciences community through the Science Education Resource Center (SERC). The results from this study will contribute to the fundamental goals of Earthscope and will be published in major peer-reviewed scientific journals and in an article for non-specialists. Data resulting from this study will be made accessible to the public in Integrated Earth Data Applications, EarthChem, and PetDB databases. A growing body of geophysical data suggests geologically recent mobility of the continental mantle beneath western North America. Several lines of evidence suggest that mantle lithosphere beneath southern California was tectonically displaced eastward by a Late Cretaceous episode of shallow subduction and "relaminated" to the base of the continental lithosphere beneath the Colorado Plateau transition zone (central Arizona). The principal investigator will test this hypothesis by comparing the petrogenetic and thermal histories of mantle xenoliths derived from both areas. If Arizona and California xenolith suites evolved in a similar manner, then a strong case can be made for major Phanerozoic displacement and subsequent reconstruction of southwest U.S. mantle lithosphere. This study will provide a geodynamic and geologic context to understand mantle displacements beneath western North America. This research will provide key constraints on the origin and evolution of mantle lithosphere beneath the southwest U.S., an enhanced ability to recognize modern and ancient analogous settings worldwide, an improved understanding of the effects of subduction angle on the stability of mantle lithosphere at craton active margin transition zones, and a high probability of recognizing a remnant of the southern California mantle lithosphere that has been "relaminated" beneath central Arizona. This result would imply a >500 km tectonic displacement of the southern California mantle fragment and provide intriguing explanations for the long-term strength of the Colorado Plateau relative to adjacent geologic provinces and for active lithospheric delamination beneath the plateau.
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/68870
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	Alan Chapman.Laramide Relamination of Mantle Lithosphere Beneath the Colorado Plateau: A Xenolith Study.2015.