All of Rhode Island was part of a volcanic arc or micro-continent called Avalonia, which formed south of the equator more than 565 million years ago.
Avalonia |
Rheic Ocean, a Paleozoic ocean between the large continent Gondwana to the south and the microcontinents Avalonia and others
Tornquist Sea, a paleo-sea between Baltica and Avalonia during early Paleozoic time