DEAD ZONE: EXPLORATIONS OF THE CRETACEOUS-PALEOGENE BOUNDARY IN NEW JERSEY

The K-Pg boundary is preserved in Monmouth County, New Jersey. The top of the Maastrichtian Tinton Formation is a highly fossiliferous unit referred to as the Pinna layer, overlain by the Burrow Unit, which includes burrows that pipe down material from the Paleocene Hornerstown Formation above (see Landman et al., 2007, 2012). We are investigating the fauna in the Burrow Unit. In contrast to the Pinna layer, the Burrow Unit is very depauperate in abundance and species richness. In previous studies investigating this site, Landman et al (2012) determined that dinoflagellates were highly abundant in the Pinna layer, and absent in the Burrow Unit. The macrofossil specimens within the burrows of the Burrow Unit originate from the Hornerstown Formation above. We focused on the fauna remaining in the matrix. We carefully collected the specimens from the matrix, as they possibly represent the surviving species after the Chicxulub impact.In our study, we discovered molds of macroinvertebrates such as Pecten venustus, Margaritella pumila, Crenella serica, Eubaculites carinatus, clusters of Cliona borings and a crab claw. It is notable that all the bivalve specimens were disarticulated. This suggests that they were not in living position. The fauna in the matrix of the Burrow Unit possibly represents the species that survived. By investigating further, we hope to better understand the environmental conditions immediately after the Chicxulub impact.