Thick sediment accumulations in deep water provide a new target in the search for oil, and require an innovative approach to hydrocarbon exploration. The Laurentian fan is a large, deep-sea (2,000 to 5,000 m) fan in the western North Atlantic, and has been the major depocenter off Nova Scotia since at least the early Tertiary. The main development of the present depositional and erosional fan morphology in the past 2 to 3 m.y. was closely related to onshore glacial history.

The slope above the fan has been the site of rapid sedimentation and consequent slumping. A network of tributaries on the upper fan appears to feed three main channel systems incised up to 800 m between broad asymmetric levees. These channels meander widely across the lower fan, then die out abruptly and pass into a lobate suprafan. Differences between the Laurentian fan and typical fan models result, in part, from the muddy nature of the sediment and the supply system.

The channels contain thick, coarse gravels which probably grade distally into sandy lobes. Both should produce good reservoir bodies with suitable source and trapping mechanisms. Fine-grained sediments were more important in fan construction. Interbedded turbidites, contourites, and hemipelagites are present in the late Quaternary-Holocene sequence. The distribution of these sediments and, in particular, the recognition of structural sequences, textural trends, and fabric types in the fine-grained turbidites can be used to characterize particular parts of the fan environment. The development of this approach should prove useful in future hydrocarbon exploration.