Collaborative Research: The Flood Basalt-Alkalic Magmatism-Kimberlite Connection and the Temporal-Spatial Evolution of the Siberian Mantle Plume

合作研究：溢流玄武岩-碱性岩浆作用-金伯利岩联系与西伯利亚地幔柱的时空演化

• 批准号: 9527053
• 负责人: Asish Basu
• 金额: $ 15.29万
• 依托单位: University of Rochester
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-08-01 至 1999-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9527053&HistoricalAwards=false
• 关键词: Collaborative; Research; Flood; Basalt; Alkalic

9527053 Basu This project is to conduct a multi-disciplinary study of field, petrologic, geochemical. isotopic and geochronological study of a suite of ultrabasic-alkaline and mafic rocks of Maimecha-Kotui region of the northern Siberian platform. The volcano-plutonic complexes of this region are closely associated in time and space with the Siberian Flood Basalt Province (SFBP) of permo-Triassic age. As part of this study The P.I.s will also include the kimberlites with the alkalic and tholeiitic pulses of the SFBP mantle plume. Preliminary data on 3He/3He measurements in olivines of the alkalic rocks suggest a lower mantle source for the 3He and links the alkalic-Maimecha phase to the plume-related SFBP. More noble gas isotope ratio measurements (He, Ne, Ar and Xe) are needed for confirmation. 40Ar/39Ar age dating of kimberlites and of the ultrabasic-alkaline and mafic rocks of the 2.8 km thick Maimecha-Kotui volcanic section are proposed to determine age and duration of volcanism. Nd, Sr, Pb-isotopic and trace elemental analyses, including the rare earth elements by TCP-MS, will also be performed on these rocks during the two-year tenure of the grant period. The analytical results will be used to examine whether there is a common petrogenetic link (e.g., mantle-derived plume) for the origin of the Kharamai kimberlites, the ultrabasic-alkaline and mafic volcanic rocks of the Maimecha-Kotui section, and for the voluminous, predominantly tholeiitic SFBP. In the event that these data do not support such a hypothesis, the acquired date will still be useful in formulating and substantiating other petrogenetic models.

9527053巴苏该项目是进行野外、岩石学、地球化学等多学科研究。北方西伯利亚地台Maimecha-Kotui地区一套超基性-碱性和镁铁质岩石的同位素和年代学研究 这一地区的火山-深成杂岩在时间和空间上与二叠纪-三叠纪的西伯利亚泛滥玄武岩区（SFBP）密切相关。 作为本研究的一部分，P.I.s还将包括SFBP地幔柱的碱性和拉斑玄武岩脉冲的金伯利岩。 碱性岩石中橄榄石的3 He/3 He测量的初步数据表明，下地幔来源的3 He和连接的碱性Maimecha阶段的地幔柱相关SFBP。 需要进行更多的稀有气体同位素比测量（He、Ne、Ar和Ar）以进行确认。 建议对2.8km厚的Maimecha-Kotui火山岩剖面的金伯利岩和超基性-碱性和镁铁质岩石进行40 Ar/39 Ar年龄测定，以确定火山作用的年龄和持续时间。 在两年的资助期内，还将对这些岩石进行Nd、Sr、Pb同位素和微量元素分析，包括TCP-MS的稀土元素分析。 分析结果将用于检查是否存在共同的岩石成因联系（例如，地幔柱）的Kharamai金伯利岩，超基性碱性和Maimecha-Kotui部分的镁铁质火山岩的起源，以及大量的，主要是拉斑玄武岩SFBP。 如果这些数据不支持这样的假设，所获得的数据在制定和证实其他岩石成因模型时仍然是有用的。