Structural and stratigraphic evolution of the continental margin offshore Nova Scotia

Introduction

The continental shelf and slope off Nova Scotia (Scotian margin) is an area of active exploration and development of oil and gas resources. Current exploration activities are expanding outward from the shelf region into the relatively unknown deep-water continental slope. Beneath the slope, the sedimentary basin typically exceeds 12 km in thickness and sits above continental crust that underwent significant thinning during opening of the North Atlantic Ocean. Basement rocks and the transition from continental to oceanic crust are buried beneath thick sedimentary fill and salt structures along much of the margin, making it difficult to determine the rifting history and thermal evolution, critical elements in basin modelling.

Project Overview

An improved understanding of the distribution and depositional history of major stratigraphic sequences will not only support the current phase of petroleum exploration and exploitation, but will also contribute greatly to the understanding of rifting processes and basin development at a global scale. This project is studying (a) the processes that affect timing and distribution of stratigraphic sequences across the margin, (b) the present structure and composition of the crust beneath the shelf and slope, and (c) the links between tectonic and stratigraphic margin evolution. Extensive mapping activities based on legacy and modern digital seismic data are being used to define the major stratigraphic units across the margin, and detailed biostratigraphic analysis is providing critical age control. Constraints on basin evolution are being obtained from a synthesis of new and existing geophysical data including seismic refraction profiles. Linking the new results with the extensive digital database will provide a comprehensive resource for future work on this margin.

Project priorities

• construction of cross-sections across the margin based on new seismic refraction data
  
• sequence stratigraphic mapping and interpretation of seismic data to determine sedimentation and erosion patterns
  
• recovery of legacy seismic data and maps and conversion to digital format
  
• development of a refined age-control framework based on biostratigraphy and other factors
  
• development of a digital atlas of selected microfossils that are the crucial tools of age determination
  
• development of plausible models of salt deformation consistent with observations
  

Project partners

• Dalhousie University
  
• Saint Mary's University
  
• Danish Lithosphere Centre
  
• TGS-Nopec Geophysical Company
  
• GX Technology
  
• Biostratigraphic Associates
  

For more information
For more information about this project, contact Dr. Sonya Dehler (Project Leader)