What is the geological significance of the Staten Island serpentinite?
The occurrence of serpentinite in the core of Staten Island is an indication that the allochthonous basement rocks consisting of oceanic crustal material were thrust landward onto the eastern margin of the continent during the Taconic orogeny.
What rock types are found on Staten Island?
The borough of Staten Island in NYC exhibits a unique suite of rocks. The most abundant rock is serpentinite, a very soft, absorbent, and argillaceous rock, consisting of serpentine (mostly the variety antigorite), with accessory minerals of chrysotile, magnetite, montmorillonite and talc.
How is serpentinite rock formed?
The serpentinite is formed by the hydrous alteration and low-temperature metamorphic alteration of igneous ultramafic rocks. These rocks are composed of olivine and pyroxene in different ratios to form peridotite and pyroxenite.
What type of ancient plate boundary does the Staten Island serpentinite represent?
Hollick (1909) suggested that the Staten Island Serpentinite is a fault bounded horst block.
How was Staten Island formed?
At the end of the Second Anglo-Dutch War in 1667, the Dutch ceded New Netherland to England in the Treaty of Breda, and the Dutch Staaten Eylandt, anglicized as “Staten Island”, became part of the new English colony of New York.
What type of geologic material is visible in this outcrop?
An outcrop or rocky outcrop is a visible exposure of bedrock or ancient superficial deposits on the surface of the Earth.
What are the big rocks on the beach called?
Jetties. Jetties are large, man-made piles of boulders or concrete that are built on either side of a coastal inlet. Whereas groins are built to change the effects of beach erosion, jetties are built so that a channel to the ocean will stay open for navigation purposes.
What rock type is the most abundant in NY?
View of a granite quarry in New York State. Granite is considered the most abundant rock in the continental crust, whereas the much denser basalt is the main component of oceanic crust.
What is serpentinite made of?
Serpentinite rocks are almost exclusively made of serpentine minerals. The most common serpentine mineral in Franciscan rocks is antigorite. This mineral gives the serpentinite its characteristic light to dark green color.
What is the composition of an average sample of the Staten Island serpentinite?
The serpentinites of Staten Island and Hoboken consist of about 95 percent serpentine with minor but highly variable olivine, anthophyllite, talc, magnetite, and trace amounts of several additional minerals.
What makes Staten Island unique?
Staten Island boasts more than 9,300 acres of parkland, giving it the nickname as the greenest borough. Often referred to by its residents as the “forgotten borough,” this southernmost borough has unique attractions that make it stand out from the rest of New York City.