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

合作研究：通过小喜马拉雅和印度克拉通之间的年代地层对比测试喜马拉雅的构造和侵蚀历史奈杰尔·休斯，加州大学河滨分校EAR-1124303舒海肖，弗吉尼亚理工大学EAR-1124026 Paul Myrow，科罗拉多学院EAR-1124518江江，大学。本项目将检验如下假设：(1)喜马拉雅山脉全部地区的古元古代、中元古代、新元古代和寒武纪是连续的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Nd值主要受沉积年龄控制，而不是受地理来源的控制；(3)新元古代和寒武纪物质的侵蚀要求该地区在目前接受之前就发生了数百万年的隆升。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，我们的结果将要求发生了连续边缘序列的渐进式剥离，最初伴随着与大喜马拉雅和特提斯喜马拉雅相同的地球化学特征的厚厚的Lh时代地层的侵蚀。因此，中新世开始隆升的时间比现在要早得多，从而显著修正了喜马拉雅地区新生代隆升的历史。因此，除了阐明印度北部边缘的变形前历史外，这一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，喜马拉雅对一系列环境问题产生了重大影响，从海水的化学到全球气候的性质。对这种影响的准确理解需要了解在这些雄伟山脉的生长过程中，全球体系是如何变化的。反过来，这需要在引发喜马拉雅隆起的事件--印度次大陆与亚洲的碰撞--之前了解情况。该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大部分的岩石与印度心脏地带的岩石之间的地质关系。这一对比将检验目前流行的一种观点，即喜马拉雅山脉的大部分地区是“异国情调”的，这意味着它最初并不依附于印度的核心大陆。这个想法很重要，因为如果正确的话，这意味着PI可以根据喜马拉雅山脉的隆升和侵蚀历史，根据时间？异国情调？而且，当真正的印度物质首次出现在喜马拉雅抬升和侵蚀的记录中时，孟加拉湾和其他地区的岩石记录了这一点。PIS的初步研究表明，“异国情调”的想法是不正确的，而且是基于对原始喜马拉雅岩石形成时代的误解。如果PI是正确的，它将表明喜马拉雅南部比目前接受的时间早500万年开始抬升，并将协调一个重要的全球地球化学变化与喜马拉雅抬升的时间。除了培训本科生和研究生外，该奖项还将促进用一种主要的印度地区语言出版关于全球环境变化的儿童-S书籍，并将其传播到孟加拉农村的乡村学校。

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.