MANHATTAN
SCHIST
Manhattan Island, in the heart of New York City, seems
prima facie an unlikely place for seeing geology. However, nice
rock outcrops occur in several city parks, including the largest, Central
Park. The bedrock in Manhattan is principally high-grade metamorphic
rocks, such as gneisses, schists, and marbles (see
geologic map of Manhattan). The
rock shown below is a typical mica schist that comes from the late
Neoproterozoic Manhattan Schist (unit ÒZmÓ on the geologic map linked to
above).
Manhattan Schist (4.6 cm across) from the Precambrian of New York
City, USA.