EXAMINING THE TORREJONIAN (To2-To3) BOUNDARY IN THE NACIMIENTO FORMATION, SAN JUAN BASIN, NEW MEXICO
In order to better understand the nature of this event, we worked intensively in the area of Torreon Wash, near the southeastern part of the San Juan Basin where the To2-To3 interval of the Nacimiento Formation is well exposed. There we collected vertebrate fossils that bracket this boundary. We also employed screenwashing and other methods to obtain microvertebrates to compensate for previous collecting biases. We tied fossil localities to measured sections obtained from both the east and west flanks of Torreon Wash. This allows direct correlation between the mammal fossil record and potential independent climate proxies preserved in strata such as megafossil plants and paleosols. Moreover, the measured sections were correlated to existing paleomagnetic data that allow correlation to the Paleocene global time scale. With these new data, we hope to test for possible correlation between this early Paleocene episode of mammal turnover and a possible shift in regional or global climate.