Collaborative Research: Equatorial Glaciation and Landscape Burial in the Late Paleozoic: Implications for Pangaean Climate and Tectonics

点击翻译按钮获取中文摘要

Climate has varied widely through Earth history. Just as study of human history helps humankind better understand our future, study of Earth's climate history aids in better understanding current and future climate systems. This study is examining whether glaciers existed near Earth's equator at low elevations some 300 million years ago. First, seismic instruments are used to see below the ground surface of Unaweep Canyon (Colorado); this canyon was located near the equator 300 million years ago and now contains features that suggest ancient glaciers may have existed during that time. Peering below the ground surface allows researchers to see the canyon shape and features, including the amount of sediment fill. Next, researchers drill out core samples from the sediment. Detailed analyses of this sediment can reveal the age of the canyon, the past climate of the region, including whether glaciers existed, and how the present-day landscape formed. If it is determined that glaciers existed in this region millions of years ago, understanding of the climate system during that time would need major revision. Computer climate models then help researchers understand characteristics of winds, ocean temperatures, volcanic eruptions, and plant cover needed to produce the climate signal revealed in the core samples. This project includes education for high-school students from the Southern Ute Indian tribe, career training and preparation for university students, and collaboration with art students to create displays and presentations about the research results.This work tests the hypothesis that low-elevation uplands of equatorial Pangaea hosted glaciers during the Late Paleozoic. To test this, geophysics, thermochronology, and coring are used to determine the depth and nature of sediment fill and 3D basement shape of Unaweep Canyon (Colorado), a globally unique landform hypothesized to archive a paleolandscape modified by Permo-Pennsylvanian equatorial glaciation. Evidence for low-latitude glaciation would radically change understanding of the late Paleozoic icehouse, a critical interval for evolution of land animals and plants, and spur research on influences of alternative boundary conditions, climate forcings, and model configurations. Documenting an upland glacial landscape preserved for 300 (or possibly 600) My would also significantly challenge understanding of landscape genesis, evolution, and burial, and feedbacks between tectonics and climate. This research involves outreach to secondary-school students from the Southern Ute Indian tribe, training of STEM undergraduate and graduate students, and interfacing with art students to create impactful public outreach.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.