NEW INFORMATION ON THE EVOLUTION OF DEVONIAN-CARBONIFEROUS SEDIMENTARY BASINS IN SOUTHERN NEW BRUNSWICK, CANADA

In the Maritimes Basin of eastern Canada, the Devonian-Carboniferous stratal succession that lies beneath the regional Namurian unconformity contains two clastic-dominated successions interpreted to be exclusively terrestrial deposits (Horton and Mabou Groups) separated by a mixed clastic-carbonate-evaporite succession which is partly marine (Windsor Group). Above the Namurian unconformity (Cumberland and Pictou Groups), the strata are generally interpreted to be infilling a thermal subsidence sag basin. Below the unconformity, new data supports the view that in southern New Brunswick, the strata infill a complex system of sedimentary sub-basins that collectively evolved in a transpressional-transtensional setting.

In the sub-basins of southern New Brunswick, several additional unconformities are now identified within the Horton Group. Seismic stratigraphy in the SE Moncton sub-basin indicates Albert Formation (Horton Group) strata accumulated in a half-graben structure, while sequence-stratigraphic interpretations of core have the strata being deposited in a primarily overfilled lacustrine basin. In part of the SW of the sub-basin, mapping and core analysis indicates that basement-fringing algal build-ups (Gays River Formation - Windsor Group) are in faulted contact with marine sublittoral wackestones (Macumber Formation - Windsor Group). New seismic data and field mapping also indicates the presence of additional post-Windsor thrusting in the area.