ISOLATION OF PYROGENIC CARBON POOLS ACROSS THE K-PG AT THE BRAZOS RIVER SITE VIA THE CHEMO-THERMAL OXIDATION 375 (CTO-375) SOOT ISOLATION TECHNIQUE

Sixty-six million years ago an asteroid struck the Yucatán Peninsula, Mexico, and caused the Cretaceous-Paleogene mass extinction. The exact mechanism of extinction is debated, but there is evidence of an impact winter brought about by massive injections of particulate matter into the atmosphere. Both charcoal and soot particles at various sites throughout the globe are cited as evidence for widespread fires at the Cretaceous-Paleogene boundary. Here, we use the operationally-defined chemothermal oxidation 375 (CTO-375) technique to better understand the fuel source(s) associated with the pyrogenic carbon isolated across the K-Pg. Specifically, soot carbon abundance and its stable isotopic signature were quantified for the River Bank South section at the Brazos River site. Preliminary results indicate that soot comprises 0.01 to 0.05 % of the total organic carbon, with δ13C ranging from about -25.2 to -24.1‰. These results provide additional insight into the global wildfire and impact winter hypotheses.