Index map
Complex north-south patterns in the six New England states mirror a convoluted geologic story. This northern part of the Appalachians consists of several terranes, fault-bounded slices of the crust that have a tectonic history distinct from adjacent rocks. The terranes, which include rocks similar to those in the British Isles, originated elsewhere but were joined (accreted) to eastern North America in the Paleozoic during the formation of Pangaea. A Paleozoic fault zone comparable to the San Andreas, intrusion of Mesozoic igneous-rock masses, and later opening of the Atlantic Ocean have further complicated this New England portrait. |
