this: collision- metamorphism- erosion resistant rock-uplands, and great crack-no metamorphism- easily eroded rock-lowlands.
Geologists usually subdivide things further into four terranes: the Newark, Proto-North American, Iapetos, and Avalonian terranes. The four also correspond beautifully with Connecticut's landscapes. The Newark Terrane is the term geologists use for the Central Valley Great Crack, and the others are subdivisions of the Uplands Collision terrane. Proto-North America, the original edge of North America before the weld, matches the Northwest Highlands. The Avalonian Terrane, a former Japan now stuck onto North America, correlates with the Mohegan Range of the Eastern Uplands. The Iapetos Terrane is a little harder to visualize geographically. It underlies both the rolling Southwest Hills of the Western Uplands and the Windham Hills of the Eastern Uplands. The Central Valley Newark Terrane splits the Iapetos Terrane in two and divides the Western Uplands from the Eastern Uplands. Basically, Connecticut is one massive terrane sandwich. From west to east the sandwich is composed of Proto-North America, lassies, Newark, Iapetos again, and Avalonia.
The relationship between the four
terranes and Connecticut's land-
scapes. Compare with the bottom
cross-section on the previous page. |
 |
