Palisades Sill

The Palisades Sill is a Triassic, 200 Ma diabase intrusion. It extends through portions of New York and New Jersey. It is most noteworthy for The Palisades, the cliffs that rise steeply above the western bank of the Hudson River. The ideal location and accessibility of the sill, as well as its unique features, have generated much attention from nature enthusiasts, rock climbers, and geologists alike.

Location

The outcrop of the Palisades Sill is quite recognizable for its prominent cliffs above the Hudson River; it is easily seen from the western portions of Manhattan. The exposure is approximately 80 kilometers (50 mi) long, most of it following the Hudson River. It first emerges in Staten Island in New York City. The sill then crosses the state line into New Jersey, where Jersey City, Union City, Fort Lee, and Englewood Cliffs all lie on it.

The sill eventually crosses back into New York, following the Hudson River north until reaching Haverstraw. It is at this point that the sill makes a turn to the west, where it disappears near Pomona. At this turn, the sill cuts across local strata, making it a dike in that area, not a sill.

Palisades Sill (New Mexico)

The Palisades Sill is a fine-grained porphyritic dacite sill which forms spectacular cliffs and palisades in the Cimarron River canyon between Eagle Nest and Cimarron in northern New Mexico. It can be seen in the eastern part of Cimarron Canyon State Park.

References

Coordinates: 36°32′12″N 105°10′30″W / 36.53667°N 105.17500°W / 36.53667; -105.17500