Spatial and Temporal Variations in Mid-Ocean Ridge Basalt Geochemistry Along and Across the East Pacific Rise Crest, 9-10N

北纬 9-10 度沿东太平洋海隆顶的大洋中脊玄武岩地球化学的时空变化

• 批准号: 0137325
• 负责人: Kenneth Sims
• 金额: $ 15.74万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-03-15 至 2006-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0137325&HistoricalAwards=false
• 关键词: Spatial; Temporal; Variations; Mid; Ocean

The PIs will measure Uranium series isotopes (230Th/238U, 226Ra/230Th, 231Pa/235U) in order to place constraints on the eruption ages of axial and off-axis lava flows in the 9-10N area of the East Pacific Rise (EPR), which has been well mapped and intensively studied with Alvin for the last decade. These U-series dates, together with new data on Sr, Nd, Pb, and Hf isotopes will be used to evaluate the petrogenesis of the samples and to evaluate the extent of near off-axis vs. axial additions to the ocean crust in this area, which seismic studies indicate should be an important process (off0axis thickening of lawer 2A). The samples will be "selected" by a "randomizing" process in order to determine theproportion of the crust that is added off-axis.

pi将测量铀系列同位素（230Th/238U, 226Ra/230Th, 231Pa/235U），以限制东太平洋隆起（EPR） 9-10N地区轴向和离轴熔岩流的喷发年龄，该地区在过去十年中已经与Alvin进行了很好的测绘和深入研究。这些u系列数据，连同Sr、Nd、Pb和Hf同位素的新数据，将用于评估样品的岩石形成，并评估该地区海洋地壳近离轴与轴向添加的程度，地震研究表明这应该是一个重要的过程（法2A的离轴增厚）。样品将通过“随机”过程“选择”，以确定添加离轴的地壳比例。