The first hydrogeological and geological maps of Jersey, Channel Islands: work by Walther Klüpfel in 1942 and Richard Nelson c. 1828

Groundwater maps for Jersey were prepared by the military geologist Walther Klüpfel in 1942, during the Second World War German occupation of the Channel Islands. Previously deemed untraceable, these maps are currently preserved in Germany at the Bundesarchiv-Militärarchiv, Freiburg-im-Breisgau, and include arguably the earliest hydrogeological map prepared at a scale of 1: 25 000 for any part of the British Isles. This antedates publication of a British hydrogeological map of the island by some 50 years, but follows a long tradition of geological mapping, the earliest geological map of Jersey having been made by a Royal Engineer officer. R. J. Nelson, about 1828. Also hitherto reported as untraceable, Nelson's field map and a fair copy intended for publication are preserved in the archives of the Geological Society, London.