ABSTRACT

Chemical, geological and geophysical studies indicate that surface slicks and oil and gas bubbles erupting at the sea surface off northeastern Baffin Island originate from natural seepage of petroleum from the seabed. The continental shelf in this area is cut by two deep submarine troughs that extend seaward from the mouths of the fjords at Scott Inlet and Buchan Gulf. Anomalies in petroleum residue concentrations have been found in the surface microlayer, water column, and unconsolidated sea-floor sediments in both the Scott and Buchan Trough areas. Bedrock samples indicate that the stratigraphic succession includes marine rocks of Late Cretaceous and Tertiary ages. Reflection seismic data indicate that older sedimentary rocks may also be represented. Free-air gravity, seismic and magnetic data suggest a thicker sedimentary section at Scott than at Buchan. The most continuous seep is at the outer part of Scott Trough, where seepage apparently originates with strata flanking a basement high near the south wall. Seepage at other localities may be more sporadic.