Collaborative research: Testing Himalayan tectonic and erosional history via chronostratigraphic correlation between the Lesser Himalaya and Indian craton

合作研究：通过小喜马拉雅山和印度克拉通之间的年代地层相关性测试喜马拉雅构造和侵蚀历史

• 批准号: 1124545
• 负责人: Ganqing Jiang
• 金额: $ 5.55万
• 依托单位: University of Nevada Las Vegas
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-10-01 至 2015-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1124545&HistoricalAwards=false
• 关键词: Collaborative; research; Testing; Himalayan; tectonic

Collaborative Research: Testing Himalayan tectonic and erosional history via chronostratigraphic correlation between the Lesser Himalaya and Indian cratonNigel Hughes, University of California, Riverside EAR-1124303Shuhai Xiao, Virginia Tech EAR-1124026Paul Myrow, Colorado College EAR-1124518Ganging Jiang, Univ. Nevada, Las Vegas EAR-1124545ABSTRACT This project will test the hypotheses that (1) the Paleoproterozoic, Mesoproterozoic, Neoproterozoic, and Cambrian of all parts of the Himalaya are part of a continuous passive margin succession and not part of an accreted terrane; (2) that neodymium isotopic values (åNd) of Himalayan rocks are primarily controlled by depositional age, rather than by geographical source; and (3) that the erosion of Neoproterozoic and Cambrian material from the northern or "inner" part of the Lesser Himalaya (LH) requires that uplift in that region took place several million years before currently accepted. Confirmation of these hypotheses, which preliminary data suggests is likely, will be achieved by detailed stratigraphic correlation between strata of the Himalayan region and the Indian craton. If confirmed, our results will require that progressive unroofing of a continuous margin succession took place, initially with erosion of a thick succession of "outer" LH-age strata with a geochemical signature identical to that of the Greater and Tethyan Himalaya. As a consequence, the initiation of uplift of the LH took place significantly earlier in the Miocene than currently invoked, thus significantly revising the Cenozoic uplift history of the Himalayan region. Hence in addition to clarifying the pre-deformational history of the northern Indian margin, this proposal will impact understanding of Himalayan tectonics, uplift, and erosion. Furthermore, the fossils present in these deposits are poorly known and detailed analysis may also provide novel insights into early eukaryotic evolution.As the world's greatest mountain chain the Himalaya has significant impact on a wide range of environmental issues, ranging from the chemistry of ocean waters to the nature of global climate. Accurate understanding of this influence requires knowledge how global systems changed during the growth of these mighty mountains. This, in turn, requires knowledge of conditions prior to the event that initiated Himalayan uplift - the collision of the Indian subcontinent with Asia. This project brings together scientists with a wide range of experience who will jointly investigate the geological relationship between rocks that make up the much of the Himalayan bedrock and those that occur within the heart of India itself. This comparison will test the currently popular idea that much of the Himalaya is 'exotic', meaning that it was not originally attached to the core landmass of India. This idea is important because, if correct, it means that PIs can 'fingerprint' the uplift and erosional history of the Himalaya based on when ?exotic? and, when truly Indian materials, first appeared in the record of Himalayan uplift and erosion recorded in the rocks of the Bay of Bengal and other areas. PIs initial studies suggest that the 'exotic' idea is incorrect, and rests on a misunderstanding of the ages of formation of the original Himalaya rocks. If PIs are right, it will suggest that the southern Himalaya began uplift 5 million years before currently accepted, and will reconcile an important global geochemical shift with the timing of Himalayan uplift. In addition to training undergraduate and graduate students, this award also will facilitate publication of children?s book on global environmental change in a major Indian regional language, and its dissemination to village schools in rural Bengal.

合作研究:通过小喜马拉雅和印度克拉通年代学对比研究喜马拉雅构造和侵蚀历史nigel Hughes，加州大学河滨分校ear - 112430，肖树海，弗吉尼亚理工大学ear -1124026， paul Myrow，科罗拉多学院ear -1124518，内华达大学，拉斯维加斯ear -1124545摘要本项目将检验(1)古元古代、中元古代、新元古代、喜马拉雅各地的寒武纪是连续被动边缘演替的一部分，而不是增生地体的一部分；(2)喜马拉雅岩石的钕同位素值（<s:1> nd）主要受沉积时代的控制，而不是地理来源的控制；(3)小喜马拉雅北部或“内部”部分新元古代和寒武纪物质的侵蚀表明，该地区的隆升发生在目前公认的几百万年前。初步数据表明，这些假设很可能得到证实，这将通过喜马拉雅地区地层与印度克拉通之间的详细地层对比来实现。如果得到证实，我们的结果将要求连续边缘演替的逐步拆除，最初是对“外部”lh时代地层的厚演替的侵蚀，其地球化学特征与大特提斯喜马拉雅相同。结果表明，中新世青藏高原的隆升起始时间明显早于目前的推测，从而对喜马拉雅地区新生代隆升历史进行了重大修正。因此，除了澄清印度北部边缘的前变形历史外，这一建议将影响对喜马拉雅构造，隆起和侵蚀的理解。此外，这些沉积物中存在的化石鲜为人知，详细的分析也可能为早期真核生物的进化提供新的见解。作为世界上最大的山脉，喜马拉雅山脉对广泛的环境问题产生了重大影响，从海水的化学成分到全球气候的性质。要准确理解这种影响，需要了解在这些巨大山脉的形成过程中全球系统是如何变化的。反过来，这需要了解引发喜马拉雅隆起的事件之前的条件——印度次大陆与亚洲的碰撞。这个项目汇集了具有广泛经验的科学家，他们将共同调查构成喜马拉雅基岩的岩石与发生在印度心脏地带的岩石之间的地质关系。这种比较将检验目前流行的观点，即喜马拉雅大部分地区是“外来的”，这意味着它最初并不附属于印度的核心大陆。这个想法很重要，因为如果正确的话，这意味着pi可以“指纹”喜马拉雅的隆起和侵蚀历史，基于何时？外来？当真正的印度物质首次出现在孟加拉湾和其他地区的岩石中记录的喜马拉雅隆起和侵蚀时。pi的初步研究表明，“外来”的想法是不正确的，并且建立在对喜马拉雅原始岩石形成年龄的误解之上。如果pi是正确的，它将表明南喜马拉雅开始隆起的时间比目前公认的早500万年，并将使一个重要的全球地球化学转变与喜马拉雅隆起的时间相协调。除了培养本科生和研究生外，该奖项还将促进儿童读物的出版。该书以印度一种主要的地方语言出版，讲述全球环境变化，并向孟加拉农村的乡村学校传播。