Dempsey, E.D., Holdsworth, R.E., Selby, D., Bird, A., Young, B., Le Cornu, C., "A revised age, structural model and origin for the North Pennine Orefield in the Alston Block, northern England: intrusion (Whin Sill)-related base metal (Cu–Pb–Zn–F) mineralization", Journal of the Geological Society, 2021