Beneath Manhattan

Did you know...

Manhattan has a bedrock unusually suited to the construction of very tall buildings. It is believed that half a billion years ago a chain of volcanic islands headed towards North America, bulldozing mud to the east coast and buried it. Over time the mud, due to intense heat and compression formed into muscovite schists, that is one of the three layers of solid bedrock that lie beneath Manhattan. The Manhattan schists layer comes near the surface in midtown and downtown, making these locations ideal for builders looking to attach skyscrapers foundation firmly into bedrock. The bedrock is so solid that ten weeks of jackhammering only moves you three feet down.

But that land drops away in the gooey middle of the island, limiting the building heights in the city. The whole region between Midtown and Wall Street, including Greenwich Village, SoHo and Chinatown would be underwater were it not filled with fathoms of debris left over from the Ice Ages. In this middle area where bedrock is buried beneath sediments, it is far more difficult to build tall buildings with structural integrity, since such buildings have to be anchored on solid bedrock, not on sediments and glacial till. This is the geology that has shaped the face of the Manhattan skyline.

                             Peace & Love