Collaborative Research: Hypothesis Testing of a Mediterranean-style Closure of the Paleo-Tethys Ocean

在与地球板块构造系统相关的地质时间尺度上，海洋盆地的产生和破坏是一个强烈影响气候模式和海洋环流、造山事件的位置和时间以及生物的演化和分布的基本过程。该项目正在检验这样一种假设，即古特提斯洋--欧亚大陆和冈瓦那之间的一个古老洋盆--以一种类似于现代地中海西部持续关闭的构造风格关闭。这一假说的提出是因为亚洲境内古老的大陆-大陆碰撞带地理上接近古特提斯洋的地质遗迹，而且这种构造组合与现代西地中海地区惊人地相似。我们正在测试的地中海式模型与其他构造模型相反，这些模型认为大陆之间的碰撞和大陆地壳的高压变质标志着洋盆的消亡和海洋俯冲的结束。相比之下，地中海式的模式涉及到毗邻碰撞大陆的洋盆的诞生和快速扩张。除了明确测试地中海式的古特提斯洋闭合，另一种假设将在这个项目中得到隐含的测试。假设检验将涉及青藏高原及其周围岩石的构造和地层分析，以及单个矿物和岩石样品的年龄和地球化学成分的确定。该项目是罗切斯特大学和西弗吉尼亚大学的教职员工、研究人员和学生以及中国科学院青藏高原研究所的科学家共同开展的多学科合作研究工作。

The generation and destruction of ocean basins on geologic timescales associated with Earth's plate tectonic system is a fundamental process that strongly influences climate patterns and ocean circulation, the location and timing of mountain building events, and the evolution and distribution of organisms. This project is testing the hypothesis that the Paleo-Tethys Ocean--an ancient ocean basin between Eurasia and Gondwana--closed in a tectonic style analogous to the modern ongoing closure of the western Mediterranean Sea. This hypothesis is motivated by the geographical proximity of ancient continent-continent collision zones within Asia to the geologic remnants of the Paleo-Tethys Ocean and the striking similarity of this tectonic assemblage to the modern western Mediterranean region. The Mediterranean-style model we are testing is counter to other tectonic models that suggest collisions between continents and high-pressure metamorphism of continental crust marks the demise of an ocean basin and the end of oceanic subduction. In contrast, the Mediterranean-style model involves the birth and rapid expansion of an ocean basin adjacent to the colliding continents. In addition to explicitly testing a Mediterranean-style closure of the Paleo-Tethys Ocean, alternative hypotheses will be implicitly tested in this project. Hypothesis testing will involve the structural and stratigraphic analysis of rocks in and around the Tibetan Plateau, and the determination of ages and geochemical compositions of individual minerals and rock samples. This project is a multi-disciplinary and collaborative research effort between faculty, researchers, and students at the University of Rochester and the West Virginia University along with scientists from the Institute of Tibetan Plateau Research in the Chinese Academy of Sciences.