Geology & Geophysics Department Seminar: Friday, 8/28/20, 12pm, Zoom

Title: Paleoclimate reconstructions with reordered clumped isotope compositions: an example from the Early Toarcian (Jurassic)

Speaker: Dr. Alvaro Fernandez Bremer

Postdoctoral Fellow, University of Bergen

Paleoclimate, Radiocarbon dating and chronology, Stable isotope geochemistry

https://www.uib.no/en/persons/Alvaro.Fernandez.Bremer

Abstract: The magnitude of temperature changes in the Early Jurassic are not well known.  Clumped isotope measurements can potentially be used to provide better constrains, but unfortunately many of the well-studied sedimentary successions that preserve Lower Jurassic fossils experienced burial temperatures above the limits of preservation of D47.  Samples from these basins are expected to be partially reordered and yield apparent clumped isotope temperatures that are warmer than original values.  My goal in this talk is to demonstrate that paleoclimate information can still be recovered from these samples.  I use reordering models and D47measurements of belemnites to show that relative temperature differences are preserved when samples experience a common burial history.    Moreover, I will show you that -- regardless of burial conditions -- partially reordered samples always preserve minimum records of temperature change across climate events.  I conclude the talk by introducing the Toarcian as an example of where partially reordered fossils can be used to reconstruct climate patterns.