CAREER: Petrogenetic Affinity of Miocene Granites to Test the Mid-crustal Channel Flow Model in the Himalaya

该研究项目的主要目标是测试预测青藏高原下印度地壳逆冲花岗岩熔融的通道流动模型，该模型是由重力驱动向南到喜马拉雅山的地形侵蚀前缘。这些花岗岩出露于喜马拉雅山地形前缘的大喜马拉雅序列中，更北的特提斯喜马拉雅序列中的花岗片麻岩穹丘中，并可能沿着青藏高原南部的喀喇昆仑断层出露。将使用野外观测、U-Pb和40 Ar/39 Ar地质年代学以及Nd和Pb同位素地球化学相结合的方法对通道流模型进行测试，以确定喜马拉雅西部（印度）和喜马拉雅东部（西藏南部）这些中新世花岗岩的来源。这项研究的结果将支持或反对喜马拉雅的通道流动模型;确定喀喇昆仑山，喜马拉雅山和西藏南部的中新世花岗岩的来源;建立藏北高原下的印度地壳俯冲的北方范围;并可能建立喀喇昆仑断层是否是一个地壳规模的结构，以及限制在断层上滑动的时间。为喜马拉雅山开发的地球动力学模型通常被出口到世界各地的其他碰撞造山带：最近，通道流模型已被应用于阿巴拉契亚山脉，加拿大科迪勒拉山脉和希腊山脉。在大陆碰撞形成的地形梯度的背景下，通道流模型明确地将气候驱动的地表过程与深部地壳过程联系起来，从而推动地质研究向新的方向发展，将构造过程与区域和全球气候变化联系起来。该项目的教育计划在弗朗西斯科州立大学开设了一门新课程，“地球科学的科学教育伙伴”，该项目将与地球科学专业的本科生和研究生以及3至6年级的教师合作，在旧金山弗朗西斯科联合学区的教室里共同开发和共同教授课程。在加州，一个地震危险很大的地区，一个甚至在气候变化之前就面临着重大土地使用和水资源挑战的州，特别需要有科学素养的公民。加州科学标准要求地球科学作为K-12科学教学重点的唯一一年是6年级;地球科学约占小学科学必修课的三分之一（到5年级），在高中的组成部分甚至更小，在加州公立学校，使3至6年级的干预成为提高K-12地球科学素养的最有希望的机会。该合作项目最重要的影响将是培养一支具有课堂教学和推广经验的毕业生骨干队伍，以及一批能够教授引人入胜的地球科学课程的小学教师。该职业奖由地球科学部的构造学、岩石学和地球化学以及教育和人力资源项目支持。

The main goal of the research project is to test the channel flow model that predicts granite melts of Indian crust thrust beneath the Tibetan plateau are gravitationally-driven south to the topographic erosional front of the Himalaya. These granites are exposed in the Greater Himalaya Sequence in the topographic front of the Himalaya, in granite gneiss domes in the Tethyan Himalaya Sequence further north, and may be exposed along the Karakoram fault in the southern Tibetan plateau. The channel flow model will be tested using a combination of field observations, U-Pb and 40Ar/39Ar geochronology, and Nd and Pb isotope geochemistry to determine the sources of these Miocene granites in the western Himalaya (India) and the eastern Himalaya (southern Tibet). Results of this research will support or argue against the channel flow model in the Himalaya; identify the source of Miocene granites in the Karakoram, Himalaya, and southern Tibet; establish the northern reach of underthrust Indian crust beneath the Tibetan plateau; and may establish whether the Karakoram fault is a crustal-scale structure as well as constrain the timing of slip on the fault. Geodynamic models developed for the Himalaya are commonly exported to other collisional orogens worldwide: most recently, the channel flow model has been applied to the Appalachians, the Canadian Cordillera, and the Hellenides. The channel flow model explicitly links climate-driven surface processes with deep crustal processes in the context of topographic gradients set up by continental collision and as a result has pushed geological research in new directions connecting tectonic processes to regional and global climate change.The education plan for this project creates a new course at San Francisco State University, "Science Education Partners in Geosciences", that will partner undergraduate and graduate students in Geosciences with grade 3 to 6 teachers to co-develop and co-teach lessons in San Francisco Unified School District classrooms. In California, an area of great earthquake hazard, and a state with major land use and water resource challenges even prior to climate change, there is a particular need for scientifically literate citizens. The only year in which California science standards require Earth Science as the focus of K-12 science instruction is the 6th grade; Earth Science comprises approximately one-third of required science instruction at the elementary level (through grade 5), and an even smaller component in high school, making intervention at grades 3 through 6 the most promising opportunity to enhance K-12 earth science literacy in California public schools. The most important broader impact of this partnership program will be the creation of a cadre of graduates with experience in classroom teaching and outreach, and a group of elementary school teachers empowered to teach engaging earth science lessons.This CAREER award is supported by Tectonics, Petrology and Geochemistry, and Education and Human Resources programs in the Division of Earth Sciences.