A series of elongate rift basins of early Mesozoic age is exposed in eastern North America in a belt extending from Nova Scotia to South Carolina. The Upper Triassic-Lower Jurassic synrift rocks that fill the basins are called the Newark Supergroup comprising continental (fluvial and lacustrine) clastic sedimentary rocks (predominantly colored red) interbedded with basaltic volcanic rocks (Froelich and Olsen, 1985). Similar basins are buried beneath the sediments of the Atlantic Coastal Plain and continental shelf.