CAREER: Environmental Forcing on the Resilience of Carbonate Platforms During the Early Cretaceous Super Greenhouse Period

University Of Texas At San Antonio, San Antonio TX

Investigators

Abstract

Shallow marine reef systems support a highly diversified community. Yet, approximately 75% of these carbonate-producing systems are threatened by ongoing warming and increased human activity. Investigating the Earth's history can increase understanding of these vulnerable systems and provide opportunities for identifying mitigation processes. About 120 million years ago, the atmospheric content of greenhouse gases increased dramatically. Under such conditions, shallow marine carbonate-producing ecosystems either survived, adapted, or disappeared. This proposal will test the hypothesis that the resilience of carbonate-producing ecosystems was favored at low latitudes by examining four locations at different latitudes, from the ancient equator to the subtropics. This project will include research opportunities for underrepresented minority students recruited from a local community college. The students will participate in a summer internship program that includes a multitiered mentoring approach and is designed to increase interest in geoscience and retention in the major. Students will have the opportunity to publish their research and serve as role models for other minority students. This project will link the adaptation of ecosystems to environmental deteriorations associated with the Oceanic Anoxic Event (OAE) 1a, by investigating carbonate platforms preserved in France, Italy, and Oman. These areas were located at different latitudes during the OAE1a and experienced diverse climate and weathering conditions. Carbonate platforms either disappeared at high paleolatitudes or transitioned into microbial communities in subequatorial settings. Determining parameters that favor the resilience of these ecosystems requires the identification of the perturbations in the carbon cycle and in the fossil assemblage associated with the OAE1a, and the appraisal of associated environmental stresses using geochemical proxies. Achieving these tasks will deepen the knowledge on feedback mechanisms between the environment and carbonate production, quantify thermal and nutrient latitudinal gradients under super greenhouse conditions, and improve the understanding of the resilience of ecosystems during a period of global paleoceanographic perturbation that could serve to mitigate the demise of modern reef systems. 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.