The Sable and Abenaki subbasins, within the Scotian basin, have been areas of active and continuous deposition since Triassic time. Mesozoic-Cenozoic sedimentary rocks in excess of 12,000 m (40,000 ft) accumulated without major unconformities. Present temperatures are therefore believed to be the maximum, and threshold levels required for the generation of hydrocarbons probably were reached in the Cretaceous.

The organic carbon is sufficient (1 to 3%) to have generated significant amounts of hydrocarbons, but the organic matter type (dominantly terrestrial) and the time and temperature relations appear responsible for the absence of good source rocks.

Organic matter coloration and type, light gas analyses, and C₁₅+ extract data all suggest that the Sable and Abenaki subbasins are thermally immature. As a result there is a marginally mature zone about 2,000 m thick which is characterized by shows of gas, condensate, and light oils. The presence of condensates, in particular, above the mature zone, is in contrast to the normal sequence of hydrocarbons in mature petroleum provinces.