Celebration of Scholarship and Creative Activity 2023
According to plate tectonic theory, the outer rigid shell of the Earth (lithosphere) is broken up into multiple sections (known as plates). These plates move slowly with respect to each other creating major belts of mountains and volcanoes that typify the surface of our planet. Although the present-day motions of plates are fairly well known, the nature and timing of ancient plate movements are poorly constrained because of the fragmentary character of the geologic record. This research focuses on better understanding the development of an ancient mountain system exposed in Antarctica known as the Ross orogenic belt. The eroded remnants of the Ross orogenic belt include igneous, sedimentary, and metamorphic rocks found along the edge of the East Antarctic craton in the Transantarctic Mountains. Previous studies that have focused on determining the ages of rocks involved in the development of the Ross orogen suggest that it reflects the convergence of plates along an ancient plate boundary ~600-500 million years ago. Other analyses of minerals that record the cooling ages of rocks suggest mountain erosion, rock uplift, and subsequent rock cooling occurred from ~525-480 million years ago. The goal of this project is to better constrain the ages of igneous crystallization (the solidification of magmas) and subsequent igneous and metamorphic cooling through new isotopic analyses of minerals separated from rocks previously collected from the Ross orogen. The data will provide new information about the age of mountain building associated with the Ross orogeny in Antarctica.