Jacques Schroeder

Palaeolandforms and morphotectonic evolution around the Baie des Chaleurs (eastern Canada)

Abstract A morphological study of the Baie des Chaleurs area, between northern New Brunswick and the Gaspe Peninsula (eastern Canada), leads to the identification of several types of palaeolandforms in the landscapes of the northeastern Appalachians. One of them, the exhumed sub-Carboniferous palaeosurface, was recognized along the shores of the Baie des Chaleurs, around the western part of the Carboniferous basin — the Maritimes Basin — which underlies the Gulf of Saint Lawrence. By analyzing the conditions of its exhumation and its relationships with escarpments limiting the higher planation surfaces of inner Gaspesie and western New Brunswick, it was possible to identify recent deformations. These are en bloc tilting and uplift, flexuring, and faulting; they partly reflect the reactivation of Carboniferous or older structures. The study of palaeolandforms has already proved to be an appropriate method for reconstructing the morphological evolution of basement areas. In this paper, it is applied to the study of the evolution of an emerged part of the eastern Canada rifted margin after the opening of the North Atlantic Ocean.