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基本过程，它强烈影响气候模式和海洋环流、造山活动的位置和时间以及生物的进化和分布。该项目正在验证古特提斯洋——欧亚大陆和冈瓦纳大陆之间的一个古老海洋盆地——以类似于现代地中海西部闭合的构造方式闭合的假设。这一假设的动机是，亚洲境内的古代大陆-大陆碰撞带在地理上接近古特提斯洋的地质遗迹，而且这一构造组合与现代西地中海地区有着惊人的相似性。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作用标志着海洋盆地的消亡和海洋俯冲的结束。相比之下，地中海式模型涉及到一个海洋盆地的诞生和快速扩张，它毗邻碰撞的大陆。除了明确测试地中海式古特提斯海洋的封闭外，该项目还将隐含地测试其他假设。假设检验将包括对青藏高原及其周围的岩石进行结构和地层分析，并确定单个矿物和岩石样品的年龄和地球化学成分。该项目是罗切斯特大学和西弗吉尼亚大学的教师、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之间的多学科合作研究成果。

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.