Abstract Reactivated Paleozoic faults provided accommodation of rift and synrift basin fill in the Triassic Fundy Basin and Orpheus Graben of the Scotian Margin. Age data ( Williams, 1985 ) suggests that the Minas Subbasin opened as early as the Anisian (242–247.2 ma) while the Orpheus Graben opened as early as the Rhaetian (201.3–208.5 ma). The Minas Fault Zone (MFZ) defines the boundary between the Avalon and Meguma terranes in the Canadian Appalachians and is exposed along mainland Nova Scotia ( Murphy et al. , 2011 ). This series of faults mark the northern flank of the Minas subbasin (Fundy basin) and Orpheus graben (Scotian basin), and were reactivated during Mesozoic regional extension. Faults nearest the highlands accommodated the coarsest material (alluvial) while faults toward the basin center accommodated relatively finer grained fluvial, aeolian, and lacustrine sediments ( Wade and MacLean, 1990 ; Leleu et al. , 2009 ). The Wolfville Formation comprises alluvial facies and generally fines upward into the Blomidon Formation aeolian sediments ( Fig. 1 ), only found along the northern boundary of the basin. Is this facies present due to local deposition within the Minas subbasin in an arid, dry zone or do aeolian sediments persist along all footwalls of eastern North American synrift basins? Figure 1. Schematic transect through the Minas Subbasin showing the structural and stratigraphic elements of this basin during rifting. Alluvial fan facies are found along the northern faulted flank of the basin, with minor occurrence of Aeolian facies. Fluvial facies are found along the entirety of the basin. Lacustrine facies are also found along the entirety of the basin but are dominantly deposited in the central areas of the basin. The Orpheus graben is an oblique trending Mesozoic extensional basin. At outcrop on the western edge of the basin, facies comprise fine to coarse-grained sandstone containing pebble to cobble clasts and having a minor mud and conglomeratic facies. These are interpreted to have been deposited in an alluvial braided channel complex nearest the mouth of the river system ( Tanner and Brown, 1999 ). To the east, more distal facies representing evaporites, playa lake and marginal marine environments are present in cores of the Eurydice Formation and represent initial opening of the Atlantic Ocean. Paleoflow indicators suggest axial rivers once existed between the two basins along the MFZ ( Tanner and Brown, 1999 ; Leleu et al. , 2009 ). Could the “Broad Terrane Hypothesis” of Russell (1879) be applicable? Was there a single connected basin which was separated into two subbasins through uplift and erosion of conjoining strata (alluvial deposits along the axial trend of the MFZ)? During basin inversion ( Withjack et al. , 1995 ; Withjack et al ., 2009 ; Withjack et al ., 1998 ) sediments deposited along the Minas Fault Zone have been uplifted and eroded. This is most likely the reason for the lack of alluvial facies present along the northern edge (footwall) of the Minas Subbasin. Facies associations of surface and subsurface synrift sediments are being characterized to discern sediment distribution patterns and sediment provenance (outcrop, thin section) and subsurface (core, cuttings, thin section).

Abstract The Scotian Basin, under Atlantic Canada’s continental shelf and slope, encompasses a corridor 100 to 150 km wide by 900 km long on the southeastern continental slope of the province of Nova Scotia, Canada. Since 1967, a total of 103 exploration wells have been drilled in the shelf portion of the basin within the setting of the Sable subbasin. The Scotian Basin is divided into a series of geologically distinct subbasins. Opening occurred during the Middle to Late Triassic, in response to separation of North America from Africa. During this time, synrift red beds, restricted marine dolomites and halites of the Eurydice, Iroquois and Argo formations, respectively, have been deposited. From the Early Jurassic to the end of the Cretaceous, the basin continues to subside, infilling with significant quantities of fluvio-deltaic and shelf sandstones. During lowstands, incision of the shelf carries sands down the paleoslope into deep marine environments, where they are deposited within a variety of subaqueous facies. The Tertiary-aged Banquereau Formation consists of fluvial, deltaic, and deep water sandstone environments. Although tectonically passive, deep water portions of the Scotian Basin contain the Scotian salt province. This subbasin is extensively deformed by halokinetic movement of Late Triassic Argo Formation halite, which mobilized to form swells, walls, ridges, and domes. Sedimentation and play-types vary considerably along the 900 km of the salt province within water depths of 1,000 to 3,000 metres with the potential for a number of distinct petroleum systems throughout the subbasins and include potential subsalt exploration targets.