Skehan and Rast (1990) suggested that the Bulgarmarsh terrane may have been thrust northwestward over the Pennsylvanian Narragansett Basin along the Beaverhead shear zone during the Alleghenian orogeny
2006) and by a Paleozoic gneiss that is related either to the Taconic orogeny or the Alleghenian orogeny
(Cardona et al.
1998; Waldron and van Staal, 2001 and references therein), whereas the Alleghenian orogeny
was due to continent collision during final closure of the Rheic Ocean.
During the Pennsylvanian Period (320-286 Ma), the collision of North America and Africa resulted in the Alleghenian Orogeny
and final assemblage of Pangaea.