After the Bronson Hill island arc, one of the next terranes to collide was the Merrimack terrane, which trends west to east in Ware, Gardner, and Southbridge, as well as encompassing the rocks of Mount Wachusett. A large number of Merrimack terrane rocks are west-dipping and date to the Silurian, including the Oakdale and Eliot formations or the Paxton schist. The Ware Belt is part of the larger terrane, characterized by west-dipping schists, the four-mile wide Hardwick pluton and the Coys Hill granite. Further north, the Gardner Belt is an anticline with significant Silurian sandstone while Paxton schist is typically associated with the Southbridge Belt.