Miramichi River - Geology

Geology

Rising in the Silurian and Ordovician rocks of the Miramichi Highlands, an extension of the Appalachian Mountains, the tributaries of the Miramichi River flow eastward into the New Brunswick Lowland, which dominates the eastern and central part of the province along the Gulf of St. Lawrence.

Erosion has created the "Miramichi River valley" (also shortened to just "Miramichi Valley"), through which the Northwest and Southwest Miramichi rivers flow. Throughout the course of both branches to Newcastle, New Brunswick, they are framed by heavily forested low hills. The highest peaks in the Miramichi River watershed, include Big Bald Mountain and the Christmas Mountains, extending to 750 m above sea level.

Soils in the Miramichi River watershed are typically acidic with shallow topsoil, lending to poor suitability for agriculture. The shorelines of the estuarine portion of the Miramichi River exposes newer rocks belonging to the Carboniferous period and underlay the sandy topsoil, however some coastal land is low lying and suffers poor drainage. Sandstone rocks are visible along the river banks.