Tectonic, Depositional, and Pleoecological History of Early Mesozoic Rift Basins, Eastern North America

Published by the American Geophysical Union as part of the Field Trip Guidebooks Series, Volume 351.

Eastern North America includes the classic Atlantic-type passive continental margin formed by the breakup of the supercontinent of Pangaea. The Triassic initiation of the breakup was marked by the formation of rifted crust all along the axis of the future Atlantic, from Greenland to Mexico. In eastern North America, nine major rift basins, mostly half-graben, and several minor basins are exposed from Nova Scotia to South Carolina, with many more buried below the coastal plain and continental shelf (Figure 1.1). The exposed rift basins, which closely follow the trend of the Appalachian orogen, filled with thousands of meters of continental sediments and basalt flows over a period of approximately 45 million years. Diabase plutons and dikes, apparently coeval with the basalt flows, extensively intruded and metamorphosed pre-existing strata. The faulted, tilted, and eroded rift strata are termed the Newark Supergroup (Van Houten, 1977; Olsen, 1978; Froelich and Olsen, 1984).