New York City is primarily composed of sediments that were metamorphosed during the Taconic and Acadian orogenies roughly 500 - 400 million years ago. Garnets can be found in the rocks of the Hartland Formation and Manhattan Schist.In these hard rocks that the skyscrapers have their foundations.
During the Pleistocene large ice sheets bulldozed the landscape. Rocks within the glaciers scraped and scratched the bedrock of Central Park producing long linear striations and grooves. Long Island is composed of rubble that the glacier left behind as it melted.
New York City lies within the North American plate and the closest plate boundary is thousands of miles away in the middle of the Atlantic. Despite its intra-plate location, the city has an unusually high number of earthquakes.