Join us for the next BPE Seminar
Investigating the geochemical context of reefs through time: From the first animal reef builders to recent coral reefs
with Amy Hagen, Ph.D, Candidate, Virginia Tech
Abstract: From Proterozoic stromatolites to today’s coral reefs, reef structures have played a critical role in shaping marine biodiversity. As the dominant reef-building organisms have changed over time, so too have the geochemical conditions of Earth’s oceans and atmosphere. My research seeks to understand the environmental factors that promote or prohibit reef development and how these thresholds have evolved over time. First, I will present insights into redox geochemistry and primary productivity during the establishment of an early animal reef, constructed by organisms called archaeocyaths, in the early Cambrian. New geochemical and micropaleontological findings from this reef, located in Nevada, highlight that reef development occurred under unstable redox conditions and may have been fueled primarily by cyanobacteria. Jumping forward in time, I will then describe the goals and early findings of a project using nitrogen isotopes to investigate the impact of Pleistocene glacial conditions on Hawaiian coral reefs as part of IODP Expedition 389. In this more recent and well-constrained setting, geochemical proxies allow us to assess the factors that cause modern reefs to thrive or struggle. Studying how reefs have repeatedly emerged, thrived, and perished during different intervals of Earth’s history provides new perspectives on how anthropogenic climate change might affect our modern reefs.
Zoom info:
https://columbiauniversity.zoom.us/j/95332400100?
Meeting ID: 953 3240 0100
Passcode: 504872
