ABSTRACT

Sedimentation on the Nova Scotia Shelf from Late Triassic - Early Jurassic to the end of Neocomian time was strongly influenced by the configuration of the Paleozoic basement. Initial deposition consisted of red beds, dolomite and halite in rift valleys which formed before breakup of the continental mass. The first major marine transgression occurred in Middle Jurassic time and is indicated by marine sands, limestone and shale.

During Middle-Late Jurassic time, regressive clastic wedges began to prograde into the pre-existing basinal areas. Normal marine limestone deposition occurred simultaneously and was apparently localized by basement highs. The clastic sediments broke through, over and around the carbonates carbonates until, in Neocomian time, the regressive deltaic sedimentation finally overwhelmed the carbonates. Culmination of clastic deposition occurred in the Cenomanian with a broad coastal channels, embayments and marine bars. Adjacent to this complex, deeper-water shales were indicative of marine transgression.

The Turonian - Early Maestrichtian world-wide transgression is evidenced by the occurrence of deep-water shales, pelagic chalk deposits and minor sands. Prograding shale wedges filled this basin in Late Maestrichtian - Paleocene time. These generally deep-water (outer neritic - bathyal) environments prevailed until Early Oligocene time, when the configuration of the shelf and the depositional environments began to approach those of the present day.