FROM THE BASE OF THE CRUST TO THE SEABED – HOW 3D REFLECTION SEISMIC VOLUMES ARE TRANSFORMING OUR UNDERSTANDING OF NOVA SCOTIA’S OFFSHORE GEOLOGY

Since 1985, exploration companies have amassed some 49 000 km² of 3D reflection seismic data across Nova Scotia’s continental shelf and slope. The Canada-Nova Scotia Offshore Petroleum Board (CNSOPB) geophysical regulations requires exploration companies to submit copies of their seismic data to the CNSOPB for archiving. As part of its resource management mandate, these data-sets are used by CNSOPB staff to evaluate the geology and hydrocarbon potential of the Canada-Nova Scotia Offshore Area, including making its geoscience interpretations and results available to a spectrum of stakeholders. In this talk, we describe the recent CNSOPB SCOPE Project designed to re-evaluate the geology of the central and western Scotian Slope after two unsuccessful deepwater exploration wells were drilled in 2015-16. Here, two large recently acquired 3D seismic volumes fill gaps between seven smaller and older volumes, providing near-contiguous coverage, and new well results provide calibration for previously unpenetrated stratigraphic intervals. The study provides new insights ranging from how the early margin evolved during plate separation with Morocco, to recent oceanographic processes involved in shaping the modern seabed, and the complex 200 Ma stratigraphic record in between. In particular the study provides a clearer picture of how potential reservoirs and source rocks are partitioned on the slope. Managing, interpreting, and communicating the geology from such immense multi-Terabyte data volumes is daunting, and to support this endeavor we have produced a public domain Atlas of 3D Seismic Surfaces and Thickness Maps meant both to make interpretation results more digestible and to seed future research. The Atlas provides a 3D model of the Scotian Slope, including the distribution of structural elements like salt bodies, faults, and folds, as well as stratigraphic elements like canyons, channels, mass transport deposits, and sediment waves. The results help us to assess natural hazards (like shallow gas and gas hydrates), improve the understanding of exploration geological risk, and define the wide spectrum of processes responsible for building, eroding, and deforming Scotian Slope strata. The results should also provide a foundation for future government, academic, and industry research in this region.