2nd Avenue, NY

  • Historical Veile (1874) map with the modern street grid superimposed and geo-referenced. Historically most of the project area was a tidal marsh along Hellgate Bay.

  • Collection of core samples from street level using a geotechnical boring rig. Continuous samples were collected to depths of 60 feet.

  • Core samples were brought back to GRA's lab facility in the Bronx for description and sub-sampling for special analyses.

  • The results of individual core profiles were correlated to develop a stratigraphic cross section of the project area.

  • By integrating our results with historical and modern maps in a GIS platform we were able to reconstruct diachronic changes of the landscape. This reconstruction shows the project area during Historical times preceding the infilling of Hellgate Bay.

2nd Avenue Subway

Geoarcheology Research Associates (GRA) was contracted to conduct geoarcheological investigations of buried landscapes on 2nd Avenue between E 92nd and E 99th Streets on the Upper East Side of Manhattan, NY.

Objectives were to assess the archaeological potential of the buried landscapes associated with a historically documented estuary and marsh and/or near shore environments beneath it. The project area was known as Hellgate Bay until it was infilled and urbanized in the late 19th century. Investigations consisted of extensive background historical and geomorphic research, field collection of five (5) cores systematically placed along the linear project corridor, and laboratory studies focused on stratigraphic interpretations, radiometric dating, and pollen, macrofossil and molluscan identifications in support of environmental reconstruction.

Stratigraphies of the primary cores were linked with an extensive collection of previously excavated geotechnical borings. The buried sequences revealed intact successions of bedrock, thin Pleistocene tills and deeper lacustrine deposits that are overlain by middle to late Holocene estuarine sediments. These borings register one of the only intact Late Quaternary sequences ever documented for Manhattan Island. Environmental studies of the Holocene deposits show that in the project area Hellgate Bay was a subaqueous mudflat. Accordingly the potential for preservation of archeological deposits is low. While no archaeological materials were recovered this project produced a wealth of important information about pre-historic ecology and landscapes of New York City.