1. Cuadrilla Resources Ltd., Cuadrilla House, 6 Sceptre Court, Bamber Bridge, Lancashire PR5 6AW, United Kingdom, huw.clarke@cuadrillaresources.com
2. School of Earth Sciences, University of Bristol, Wills Memorial Building, Queen’s Road, Bristol BS8 1RJ, United Kingdom, james.verdon@bristol.ac.uk, tom.kettlety@bristol.ac.uk, alan.baird@bristol.ac.uk, gljmk@bristol.ac.uk