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: 1124518
• 负责人: Paul Myrow
• 金额: $ 6万
• 依托单位: Colorado College
• 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=1124518&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Nigel Hughes，加利福尼亚大学河滨分校 EAR-1124303Shuhai Shaw，弗吉尼亚理工大学 EAR-1124026Paul Myrow，科罗拉多学院 EAR-1124518Ganging Jiang，大学内华达州，拉斯维加斯 EAR-1124545摘要 该项目将测试以下假设：(1) 喜马拉雅山所有部分的古元古代、中元古代、新元古代和寒武系是连续被动边缘序列的一部分，而不是增生地体的一部分； (2) 喜马拉雅岩石的钕同位素值 (åNd) 主要受沉积时代控制，而不是地理来源； (3) 来自小喜马拉雅山 (LH) 北部或“内部”部分的新元古代和寒武纪物质的侵蚀要求该地区的隆起发生在目前公认的数百万年前。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和印度克拉通地层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序列的屋顶逐渐剥落，最初会侵蚀厚厚的“外部”序列。 LH 年龄地层的地球化学特征与大喜马拉雅山和特提斯喜马拉雅山相同。因此，LH 的隆升起始发生在中新世明显早于目前的说法，从而显着修正了喜马拉雅地区的新生代隆升历史。因此，除了澄清印度北部边缘变形前的历史之外，该提议还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进化提供新的见解。 作为世界上最大的山脉，喜马拉雅山对从海水化学到全球气候性质等广泛的环境问题具有重大影响。准确理解这种影响需要了解全球系统在这些巨大山脉的生长过程中如何变化。反过来，这需要了解喜马拉雅山隆起事件（印度次大陆与亚洲碰撞）之前的情况。该项目汇集了具有广泛经验的科学家，他们将共同研究构成喜马拉雅基岩大部分的岩石与印度中部的岩石之间的地质关系。这一比较将检验目前流行的观点，即喜马拉雅山的大部分地区是“异国情调”的，这意味着它最初并不属于印度的核心陆地。这个想法很重要，因为如果正确的话，这意味着 PI 可以“指纹识别”。喜马拉雅山的隆起和侵蚀历史基于“外来”且真正的印度材料首次出现在孟加拉湾和其他地区岩石记录的喜马拉雅隆起和侵蚀记录中。 PI 的初步研究表明，“异国情调”？这种想法是不正确的，它是对喜马拉雅山原始岩石形成时代的误解。如果PI是正确的，这将表明喜马拉雅山南部开始隆起的时间比目前所接受的早500万年，并将使重要的全球地球化学变化与喜马拉雅隆起的时间相一致。除了培训本科生和研究生外，该奖项还将促进以印度主要地方语言出版有关全球环境变化的儿童读物，并将其传播到孟加拉农村的乡村学校。