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喜马拉雅之间的年代地层对比测试喜马拉雅构造和侵蚀历史Nigel Hughes，加州大学，滨江肖树海，弗吉尼亚理工大学，1124026保罗·麦罗，科罗拉多学院，1124518江刚，内华达州，拉斯维加斯，1124545摘要本项目将测试以下假设：（1）古元古代，喜马拉雅地区中、新元古代和寒武系是一个连续的被动边缘序列的一部分，而不是一个增生的陆缘序列的一部分：（2）喜马拉雅岩石的钕同位素值（Δ Nd）主要受沉积时代的控制，而不是受地理来源的控制;（3）来自小喜马拉雅（LH）北方或“内部”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几百万年前。初步数据表明，这些假设的证实是可能的，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，我们的研究结果将需要一个连续的利润继承渐进的去顶发生，最初的“外”LH-年龄层的地球化学签名相同的大和特提斯喜马拉雅厚继承的侵蚀。因此，启动隆升的LH发生在中新世比目前调用，从而显着修订新生代隆升历史的喜马拉雅地区。因此，除了澄清前变形历史的北方印度边缘，这一建议将影响喜马拉雅构造，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进化提供新的见解。喜马拉雅山脉是世界上最大的山脉，它对从海洋沃茨的化学性质到全球气候的性质等一系列环境问题都有着重大影响。要准确理解这种影响，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发生前的条件。印度次大陆与亚洲的碰撞。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，即喜马拉雅山的大部分是“异国情调”的，这意味着它最初并不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可以根据“外来”和真正的印度材料何时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山隆起和侵蚀记录中，来“指纹”喜马拉雅山的隆起和侵蚀历史。PI的初步研究表明，“异国情调”的想法是不正确的，并依赖于对原始喜马拉雅岩石形成年龄的误解。如果PI是正确的，它将表明南喜马拉雅山在目前接受的500万年前开始隆起，并将使一个重要的全球地球化学变化与喜马拉雅山隆起的时间相一致。除了培养本科生和研究生，这个奖项还将促进儿童的出版？他用一种主要的印度地方语言编写了一本关于全球环境变化的书，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.