The continent was actually Laurentia back then. Lake Ontario, the St Lawrence Valley and the Gulf of St Lawrence are all part of the same rift.
Lakes Michigan, Huron and Erie are all the shorelines of ancient seas that were ringed by coral. This left behind soft Calcite rock that the glaciers carved away.
The continent was actually Laurentia back then. Lake Ontario, the St Lawrence Valley and the Gulf of St Lawrence are all part of the same rift.
Lakes Michigan, Huron and Erie are all the shorelines of ancient seas that were ringed by coral. This left behind soft Calcite rock that the glaciers carved away.