GSA Connects 2023 Meeting in Pittsburgh, Pennsylvania

Paper No. 166-13
Presentation Time: 8:00 AM-5:30 PM

NEW PALEONTOLOGICAL DISCOVERIES FROM THE EARLIEST-UPPER CRETACEOUS RARITAN FORMATION ON LONG ISLAND, NEW YORK


HART, William1, BENNINGTON, J.1, LABARCA, Rebecca2, MARSH, Gianna3 and PHILLIPS, Anya4, (1)Geology, Environment, and Sustainability, Hofstra University, Hempstead, NY 11549, (2)Amityville Memorial High School, Amityville, NY 11701, (3)Elmont Memorial High School, Elmont, NY 11003, (4)Uniondale High School, Uniondale, NY 11553

The geology of Long Island consists primarily of Pleistocene glacial deposits with underlying Cretaceous coastal plain layers below sea level. Allochthonous blocks of Cretaceous sediments attributed to the Raritan Formation were incorporated into deposits of the Harbor Hill moraine and are now exposed in the shoreline cliffs along northwestern Long Island. The stratigraphy and paleontology of these exposures have been documented in the literature going back over approximately 180 years, including descriptions of pollen and plant fossils. Despite this rich record of flora, there is no confident documentation of amber or vertebrate fossils in the Cretaceous of Long Island. We have sampled, disaggregated, and performed grain-size analysis on Raritan sediments from Makamah Beach (Northport, NY), Caumsett State Park (Lloyd Harbor, NY), and Garvies Point (Glen Cove, NY), looking for vertebrate and other microfossils by carefully sieving samples of sand and clay and picking them under a microscope. Here we report the first vertebrate remains (a bone fragment and a fish vertebra) from the Cretaceous of Long Island, as well as small pieces of amber from clay deposits rich in fossil plant material, which may represent the first documented reports of amber from Long Island. The amber-bearing clays have several characteristics in common with the South Amboy Fire Clay Member of the Raritan Formation in New Jersey. Although exposures are limited, the Raritan deposits on Long Island provide a window into the distributary lobe depositional environments that existed in the beginning of the Late Cretaceous along the northern Atlantic continental margin.