Cameron's Line

Cameron's Line is an Ordovician suture fault in the northeast United States which formed as part of the continental collision known as the Taconic orogeny around 450 mya. Named after Eugene N. Cameron, who first described it in the 1950s, it ties together the North American continental craton, the prehistoric Taconic Island volcanic arc, and the bottom of the ancient Iapetus Ocean.

Location

Cameron's line has been identified in western Connecticut near Ridgefield before it heads into the Bronx, along the East River in Manhattan, through New York Bay, Staten Island and into New Jersey.

Geology

The basement rocks of the Manhattan Formation located on the western side of Cameron's line are metamorphosed sedimentary rocks. They were formed in roughly this location (autochthonous) and have been tectonically stable over a large period of time. The other side of the line has allochthonous rocks formed elsewhere, which have experienced great tectonic movement in a westward direction on top of the underlying bedrock

Near New York City, the eastern side of the line is the Hartland Formation, the remains of the volcanic island arc underneath Cretaceous and Pleistocene layers. The nearby Newark Basin in New Jersey is similar to a layer underneath the Cretaceous period rocks in this region.

The position of the line in New York City and especially in Manhattan is subject to much debate and contradictory data. Due to the violent nature of the Taconic Orogeny, the line has been folded and eroded several times. The material in the line is described as "highly laminated, migmatized, complexly folded- and annealed zones of commingled mylonitic rocks".