Water supply maps for northern France created by British military geologists during World War II: precursors of modern groundwater development potential maps by N.S. Robins, E.P.F. Rose, and J.C. Clatworthy Quarterly Journal of Engineering Geology and Hydrogeology Volume 40(1):47-65 February 13, 2007 © 2007 The Geological Society of London

Top: geological map of northern France, simplified from part of 1:1000 000 scale GSGS 4452 map of 1943, with grid indicating coverage of water supply maps at scale of 1:250 000 prepared in 1944 (see Table 3). Top: geological map of northern France, simplified from part of 1:1000 000 scale GSGS 4452 map of 1943, with grid indicating coverage of water supply maps at scale of 1:250 000 prepared in 1944 (see Table 3). Bottom: larger-scale geological map for part of this region (approximately equivalent to sheets 3a & 8, 4 and 1), similarly simplified, showing coverage of water supply maps at scale of 1:50 000 prepared in 1943–44 (see Table 1). N.S. Robins et al. Quarterly Journal of Engineering Geology and Hydrogeology 2007;40:47-65 © 2007 The Geological Society of London

Diagrammatic geological cross-section WSW–ENE across part of Normandy (sheets 7F/1 to 8E/5 of Fig. 1, bottom), with major towns (named in upright font) and rivers (italic). Diagrammatic geological cross-section WSW–ENE across part of Normandy (sheets 7F/1 to 8E/5 of Fig. 1, bottom), with major towns (named in upright font) and rivers (italic). Key: grey stipple – basement; t2 – Triassic sandstones and conglomerates; j2 – massive (Jurassic) oolitic limestones; j3+2 – mixed sequence including (later Jurassic) marls, clays, sandstones and limestones; c2 – Chalk overlying Greensand and Gault Clay (all Cretaceous). After Aldwell et al. (1978), by kind permission. N.S. Robins et al. Quarterly Journal of Engineering Geology and Hydrogeology 2007;40:47-65 © 2007 The Geological Society of London

Diagrammatic geological cross-section W–E through the town of Caen (cf. Diagrammatic geological cross-section W–E through the town of Caen (cf. Fig. 2), showing principal aquifers. After Bigot (1932). Shallow boreholes are indicated in alluvium flooring the valley of the River Orne and in Quaternary loess (limon) as well as bedrock, with indication of original rest water level. Armorican basement is successively overlain by: the Lias (Lower Jurassic clays and subordinate limestones); ‘oolites’ (a unit 20–25 m thick, of Middle Jurassic Aalenian to Bajocian age, currently regionally described (Rioult et al. 1991) in terms of three formations: the Malière, 7–8 m of marly biomicrite with cherts and glauconite; overlain by Ferruginous Oolite, 0–2 m of fossiliferous condensed ironshot oolite; and Sponge Limestone, 8–20 m predominantly of ‘white oolite’ containing sponge spicules); the ‘blue bed’ (the current Port-en-Bessin Marl Formation, 8–28 m of early Bathonian marls alternating with limestones, a unit thickening westwards from Caen); the Caen Limestone Formation (fine biodetrital limestone). This is overlain regionally by cross-bedded bioclastic limestone, currently designated the Creully Formation, and by three similar formations which alternate with thin clayey limestones. This mid-late Bathonian limestone sequence is some 68–84 m in total thickness. Unit (b) contains the ‘Nappe Bajocienne’, (d) the ‘Nappe Vésulienne’, of Bigot (1932), cited in Table 2 herein as the Bajocian and Bathonian aquifers respectively. N.S. Robins et al. Quarterly Journal of Engineering Geology and Hydrogeology 2007;40:47-65 © 2007 The Geological Society of London

Map area from sheet 7E/5 Creully, a 1:50 000 scale water supply map prepared for a militarily significant area of Mid-Jurassic rocks. Map area from sheet 7E/5 Creully, a 1:50 000 scale water supply map prepared for a militarily significant area of Mid-Jurassic rocks. See Figure 1 for regional setting, legend based on marginalia. From an original map courtesy of the Lapworth Museum of Geology, but showing in addition sites of 10 boreholes, numbered as in Table 2. N.S. Robins et al. Quarterly Journal of Engineering Geology and Hydrogeology 2007;40:47-65 © 2007 The Geological Society of London

Map area from sheet 7F/1 Caen, a 1: 50 000 scale water supply map prepared for a militarily significant area of Mid-Jurassic rocks. Map area from sheet 7F/1 Caen, a 1: 50 000 scale water supply map prepared for a militarily significant area of Mid-Jurassic rocks. See Figure 1 for regional setting, legend based on marginalia. From an original map courtesy of the Lapworth Museum of Geology, but showing in addition sites of 9 boreholes, numbered as in Table 2. N.S. Robins et al. Quarterly Journal of Engineering Geology and Hydrogeology 2007;40:47-65 © 2007 The Geological Society of London

Map area plus legend from sheet 7F/4 Le Havre, a 1: 50 000 scale water supply map prepared late in the production sequence for a militarily significant area of Cretaceous rocks: see Figure 1 for regional setting and text for transcription of legend. Map area plus legend from sheet 7F/4 Le Havre, a 1: 50 000 scale water supply map prepared late in the production sequence for a militarily significant area of Cretaceous rocks: see Figure 1 for regional setting and text for transcription of legend. Courtesy of the Lapworth Museum of Geology. N.S. Robins et al. Quarterly Journal of Engineering Geology and Hydrogeology 2007;40:47-65 © 2007 The Geological Society of London

Map area, including legend, for sheet 9D/5 Dieppe, a 1: 50 000 scale water supply map prepared early in the production sequence for a significant port area of Cretaceous rocks: see Figure 1 for regional setting. Map area, including legend, for sheet 9D/5 Dieppe, a 1: 50 000 scale water supply map prepared early in the production sequence for a significant port area of Cretaceous rocks: see Figure 1 for regional setting. Courtesy of the Lapworth Museum of Geology. N.S. Robins et al. Quarterly Journal of Engineering Geology and Hydrogeology 2007;40:47-65 © 2007 The Geological Society of London

Map area, including legend, for sheet 49 Boulogne, a 1: 50 000 scale water supply map prepared early in the production sequence for a significant port area predominantly of Jurassic and Cretaceous rocks: see Figure 1 for regional setting. Map area, including legend, for sheet 49 Boulogne, a 1: 50 000 scale water supply map prepared early in the production sequence for a significant port area predominantly of Jurassic and Cretaceous rocks: see Figure 1 for regional setting. Courtesy of the Lapworth Museum of Geology. N.S. Robins et al. Quarterly Journal of Engineering Geology and Hydrogeology 2007;40:47-65 © 2007 The Geological Society of London

Map area of sheet 4 Havre-Amiens, an example of the 1: 250 000 scale water trace map series prepared by British military geologists in 1944: see Figure 1 for regional setting, Figure 7 for part of the area at more detailed scale. Map area of sheet 4 Havre-Amiens, an example of the 1: 250 000 scale water trace map series prepared by British military geologists in 1944: see Figure 1 for regional setting, Figure 7 for part of the area at more detailed scale. Courtesy of the Lapworth Museum of Geology. N.S. Robins et al. Quarterly Journal of Engineering Geology and Hydrogeology 2007;40:47-65 © 2007 The Geological Society of London