OR/18/004 Priority areas for further work

Goodenough, K M, Jones, D, and Ford, J. 2018. Geological mapping of Sierra Leone: baseline assessment and next steps. British Geological Survey Open Report, OR/18/004.

Any final decisions on priority areas for geological mapping should be made in the context of the forthcoming nationwide airborne geophysical survey. Combination of this survey with geological mapping at 1:100 000 or ideally 1:50 000 scale (World Bank, 2017) should allow development of an improved national map. Within this map, features such as late-tectonic granitoids and Mesozoic dykes should be mapped and represented in a consistent way across the country. It is evident that there is a need for more detailed understanding of large-scale structures across Sierra Leone, including major shear zones that may host mineralisation of a range of ages, and these areas should be targeted with more detailed investigation. Areas of particular interest include the supracrustal belts within the Archaean basement, and the Kasila Group. In the coastal strip, both the Bullom Group and the Freetown Complex deserve further attention due to the importance of this area for natural hazards, mineral and energy resources, groundwater and urbanisation. Any new mapping should be supported by appropriate data standards, management procedures and infrastructure to ensure its consistent capture and effective delivery.