1. Geological Survey Map, Sheets 41, N.E.; 42, N.W.; 56, N.W., S.W., and S.E.; 60, S.W.
2. Geological Index Map (4 miles to an inch), Sheets 8 (chiefly), and 10, 11 (parts).
3. Geological Horizontal Sections 5, 6.
4. Ordnance Survey (New Series) Sheets.