Week 5 Convergent-Plate | LI Sound

Week 5 Convergent-Plate | Long Island Sound

The creation of the Long Island Sound started over 500 million years ago and is a result of plate convergence and collision.  As continental plates and oceanic plates began to collide between 460 to 270 million years ago thus began the formation of Connecticut and Long Island.  Since the meeting of the crust where that of continental and oceanic plates the result was that of the oceanic crust to sink inward toward the Earths core (subduction) while the thicker continental plate rode over the top. 

Areal View of Long Island Sound

Over the 500 million years we come to today's current layout of the Long Island sound which sits between NY and Connecticut.  As plate rock cooled and became more brittle became susceptible to erosion from the opening of the Atlantic Ocean which caused fracturing, faulting, and rifting between the North and South alignment fo the bedrock between New England and New York.  This allowed for the formation of a network of south draining valleys and streams from Connecticut followed with two recent glaciations partnered to ware down and erode the rock units.  Combining fragmented rock and fractured fault zones allowed the erosion needed for the creation the Long Island Sound we see today.   

Image Source:
Long Island Sound Resource Center. http://www.lisrc.uconn.edu/lisrc/geology.asp?p2=History&p3=glhct