and folding rock into an origami landscape. This was the birth of the Appalachian Mountain belt, which includes the Uplands of Connecticut. The Uplands then may well have been among the world's tallest mountains, concluding Connecticut's Paleozoic history on a high note.

The Great Crack

Compared to the metamorphic mishmash of the Uplands Collision terranes, the story of the Central Valley's Newark Terrane is much more certain. Since its formation in the Mesozoic as a great crack during Pangaea's break-up, the Central Valley's brownstone and traprock have escaped the grasp of continental collision. The geology of the region remains straightforward, uncorrupted by the rock-and-roll twists and turns of regional metamorphism. As a result, the Newark Terrane, relative to the Collision terranes, is quite well understood. By the end of the Keith century, geologists had worked out all of the Central Valley's main features, and most of the details as well. And unlike views on the Uplands, the opinions of geologists concerning the Central Valley's traprock and brownstone have changed little since then.

The only major change in our understanding of the Central Valley came about with the plate tectonic revolution and the identification of the Valley as part of a terrane, the Newark Terrane. Similar basins of Mesozoic traprock and brownstone line both sides of the Atlantic Ocean, from South America to Newfoundland, and from Africa to western Europe. The name of the terrane comes from the particularly well-studied Mesozoic basin containing the city of Newark, New Jersey. Even within New England, the Central Valley has company. In the towns of Southbury and Woodbury, a miniature version of the Central Valley, called the Pomperaug Valley, sinks into the Western Uplands (see Chapter 3). In the 1950s, another little basin of brownstone (without traprock) about 3 square miles in size was discovered along Cherry Brook in Canton, Connecticut. A third basin lies underneath Cape Cod, buried by more recent sediments. In 1983, still another section of Newark

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