Staten Island
Geology
The Palisades Sill has been designated a National Natural Landmark, being "the best example of a thick diabase sill in the United States." It underlies a portion of northwest Staten Island, with a visible outcropping in Travis, off Travis Road in the William T. Davis Wildlife Refuge. This is the same formation which appears in New Jersey and upstate New York along the Hudson River in Palisades Interstate Park. The sill extends southward beyond the cliffs in Jersey City beneath the Upper New York Harbor and resurfaces on Staten Island. The Palisades sill date from the Early Jurassic period, 192 to 186 million years ago.
Staten Island-42