In New York City, Cameron's Line, a tectonic boundary which shows evidence of extreme compression and thrust faulting, separates the Manhattan Prong with its Middle Proterozoic Fordham Gneiss overlain by C and O allochthonous units on the west, from the allochthonous eugeoclinal Hartland Formation and Ravenswood Granodiorite on the east. The Hartland is mapped in the east Bronx and Queens; the Ravenswood is in Queens, Kings, and lower east Manhattan. All 3 of these were previously mapped as Brooklyn Gneiss or Brooklyn Injection Gneiss which should be abandoned. The age of the Hartland and Ravenswood is Cambrian and Ordovician, based on correlation with rocks of southwestern CT, their relative positions and lithologic similarities. Isotope data on the Ravenswood gives an early Paleozoic age, probably Early Ordovician.

Source: GNU records (USGS DDS-6; Reston GNULEX).