Collaborative Research: Insights into plume-lithosphere interactions from Hawaiian mantle xenoliths

合作研究：从夏威夷地幔捕虏体中洞察地幔柱-岩石圈相互作用

• 批准号: 0241052
• 负责人: Vincent Salters
• 金额: $ 4.52万
• 依托单位: Florida State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-03-01 至 2006-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0241052&HistoricalAwards=false
• 关键词: Collaborative; Research; Insights; into; plume

This study will involve petrographic work, mineral chemical analysis (major and trace elements), and Hf, Os, Sr, Pb, and Nd isotope study of mineral separates from spinel peridotite and garnet "pyroxenite suite" xenoliths from the post-erosional Honolulu Volcanics (HV) of Oahu. The xenoliths come from three vents: Salt Lake crater (SLC) is located on the rim of the Koolau volcano; and Kaau and Pali vents are located close to its caldera. The first order goal under this award is to infer xenolith origins using the combined isotopic and mineral chemical information. The isotopic information and mineral thermobarometry on the xenoliths will allow the PIs to recognize the types of materials (subducted crust and mantle or even lower mantle or transition zone materials) that may have been brought up by the Hawaiian plume versus those that have a lithospheric origin. The study will offer a direct insight into the isotopic variability of the shallow mantle beneath Oahu irrespective of their origin in the plume, the lithosphere, or as a mixed product of plume, lithosphere or asthenosphere- derived components. Once these are identified, existing models on Hawaiian volcanism and lithospheric processes may be fine-tuned or better models may be proposed.

这项研究将包括岩相学、矿物化学分析(主要和微量元素)以及对瓦胡岛后火奴鲁鲁火山(HV)中尖晶石橄榄岩和石榴石“辉石岩套”包体矿物的Hf、Os、Sr、Pb和Nd同位素研究。捕虏体来自三个喷口：盐湖火山口(SLC)位于库劳火山的边缘；考乌和巴利喷口位于靠近火山口的地方。该奖项的首要目标是利用同位素和矿物化学的综合信息推断捕虏体的来源。包体上的同位素信息和矿物温度压力测量将使PI能够识别可能是由夏威夷热柱带来的物质类型(俯冲的地壳和地幔，甚至是下地幔或过渡带物质)，而不是那些来自岩石圈的物质。这项研究将直接揭示瓦胡岛下浅层地幔的同位素变异性，无论其起源于岩浆柱、岩石圈，还是来自岩浆柱、岩石圈或软流圈的成分的混合产物。一旦确定了这些，关于夏威夷火山活动和岩石圈过程的现有模型可能会微调，或者可能会提出更好的模型。