Ashes, Ashes, All Fall Down
Tuesday March 9th
Room 417 Schermerhorn Hall
Summary: The presence of volcanic ashes interlayered in sediments and sedimentary rocks provides relative time lines that allow geologists to confidently correlate non-continuous deposits. Geochronologists use these deposits to make estimates of the absolute time lines. Significant developments in the past decade in both 40Ar/39Ar and U-Pb radio-isotopic chronometry allow unprecedented levels of precision for dating volcanic layers, and it is now possible to evaluate rates of geological and climate change and provide calibrations for major biological events in deep time. Improved precision for each chronometer has also highlighted important limitations on accuracy and precision that make the development of a multi-chronometer timescale challenging. The EARTHTIME initiative is focused on resolving these limitations (research opportunities!). I will talk about some of the applications of volcanic ash deposits for studying geological processes and events.
Associate Professor Sidney Hemming's research aims to shed light on the provenance and processes recorded in the geochemistry of sediments and sedimentary rocks. Related research interests include geochronology, paleoclimate, and continental crust evolution. Sidney has an active program of applying radiogenic isotopes for tracing the sources of sediments with the goal of understanding Quaternary climate changes and associated changes in winds, currents and glaciers.
Sidney earmed her B.S. from Midwestern and an M.S. from Tulane prior to pursuing her Ph.D. at SUNY Stony Brook.
Future talks are scheduled for Tuesdays from 12:15-1:00pm in Room 417 Schermerhorn Hall. Attendees are welcome to bring their lunch.
All are welcome to attend!