(Geoarcheology Research Associates, Yonkers, N.Y., USA)
Keywords: Geoarchaeology, subsurface coring, GIS
Rapid urban development is decimating the buried vestiges of ancient landscapes at an exponential rate. In New York City, the impacts of the World Trade Center disaster coupled with rapid development has all but eradicated the buried evidence for the city’s complex landscape history. Diverse projects undertaken several years before and after the disaster facilitates landscape reconstructions of this area, which straddles the dynamic margins of marine, estuarine, and terrestrial eco-zones at the glacial margin. Prior to initial 17th century Dutch occupation, Manhattan’s topography was steep to undulating, preserving many of the glacial features characteristic of a terminal moraine setting. Euroamerican and industrial age land use left a complex but well stratified urban sequence. Landform chronologies bearing on occupation since the earliest Native American occupations (Late Pleistocene/Early Holocene) are preserved albeit in fragmentary form. Holocene shoreline reconstructions help model rates of sea level rise. The urban fill stratigraphy illustrates how the early Euroamericans modified shorelines to stabilize Manhattan Island and established this city as the USA’s primary commercial center. For most projects we use minimally-invasive geoprobes to identify baseline stratigraphies. Sedimentological, palynological and molluscan records facilitate environmental reconstructions that are dated by radiocarbon. It is possible to model changing shoreline ecologies with detailed core strataigraphies that can be “retrofitted” to geotechnical cores obtained by engineering geologists. The structure of NYC compliance archaeology requires that individual sites be investigated in accordance with access limitations and permitting requirements. Different subsurface approaches are therefore used for each project. However, with GIS it is now possible to synthesize reconstructions across the broader urban footprint. The types of projects that gave rise to this synthesis exemplify the ways in which development driven research will pilot the course of geoarchaeology in the 21st century.