Trench Map Ploegstreet SW4 Ed 6
6B. PLOEGSTEERT GEOLOGICAL. Showing suitability of land for Dug-Outs, etc. Scale 1:10,000 dated 5/18. An unusual map containing descriptions of the area Messines-Ploegsteert-Welverqhem-Warneton whereas marked areas denote such things as Alluvials mostly too deep for dug-outs. Most of the ground covered by this map is of this kind. Boreholes drawn to establish this are clearly indicated.