Collaborative Research: The Transition from Rifting to Seafloor Spreading at the Western Tip of the Cocos-Nazca Rift

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项目编号	1558592
	Collaborative Research: The Transition from Rifting to Seafloor Spreading at the Western Tip of the Cocos-Nazca Rift
	Emily Klein
主持机构	Duke University
项目开始年	2017
	2017-09-01
项目结束日期	2019-08-31
资助机构	US-NSF
项目类别	Standard Grant
项目经费	267840(USD)
国家	美国
语种	英语
英文摘要	OCE 1558592 Collaborative Research: The Transition from Rifting to Seafloor Spreading at the Western Tip of the Cocos-Nazca Rift Abstract for posting A long-standing question in the study of mid-ocean ridges focuses on how they initiate and evolve. Our research cruise to the Galapagos Triple Junction in the eastern equatorial Pacific Ocean will characterize the transition from initial rifting to seafloor spreading, and the associated development of ridge axis segmentation. In this region, the western tip of the Cocos-Nazca Rift is breaking into ~0.5 Ma crust accreted on the east flank of the East Pacific Rise, and each stage in the transition from rifting to magmatic seafloor spreading can be studied. In order to examine along-axis changes as a function of distance from the rift tip, we will collect geophysical data on morphology, gravity and magnetic variations, rock samples for chemical analyses, and water column data for identifying hydrothermal activity. Our findings on oceanic rifting will complement on-going studies of these processes in continental rift settings. Our study area extends eastward from the site of initial rifting of the Cocos-Nazca spreading center to nucleantion of magmatic spreading at the Hess Deep rift, to full magmatic spreading, thus exhibiting progressive stages in the initiation and development of rifting and segmentation. Multibeam bathymetry, gravity, and magnetic data will be collected to reconstruct the tectonic evolution from initial rifting through seafloor spreading, and in particular, changes in segment and offset characteristics as they develop. Chemical analysis of rock samples collected along the spreading axes and along flow lines will shed light on the evolution of mantle melting and melt delivery systems and their relationship to the tectonic segmentation. Graduate and undergraduate students (Duke and MIT/WHOI), will participate in the cruise and on-shore research, gaining valuable seagoing experience and learning to conduct collaborative research. In addition, we will develop activities based upon this work for use in a yearly science-immersion program for minority, middle school girls.
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文献类型	项目
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/71797
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	Emily Klein.Collaborative Research: The Transition from Rifting to Seafloor Spreading at the Western Tip of the Cocos-Nazca Rift.2017.