Skip to main content

Science – Society – Technology

Geothermal Energy Cover Image
Fig. 7 | Geothermal Energy

Fig. 7

From: Detailed descriptions of the lower-middle Triassic and Permian formations using cores and gamma-rays from the EPS-1 exploration geothermal borehole (Soultz-sous-Forêts, Upper Rhine Graben, France)

Fig. 7

a EPS-1 gamma-ray log between the Couches de Karlstal and the Grès Anté-Annweiler showing the limits and b cores from EPS-1 from the middle Buntsandstein to the Variscan basement. Box 241: “caviar-like” facies sandstone typical from the Couches de Karlstal. Box 326, Couches de Rehberg: coarse sandstone with white quartz pebbles and a filled fracture (white circular arc). Box 446, Couches de Trifels: coarse-grained sandstone with white quartz pebbles and a decolored level. Box 472, Grès d’Annweiler: clayey sandstone with high frequency rip-up clay clasts of all sizes rounded or angular. Box 537, Grès d’Anté-Annweiler: coarse-grained clayey arkosic sandstones with a thick clay level at the base. Boxes 545 and 1003, Variscan granitic basement: unaltered monzogranite with K-feldspar megacrystals and oxidized facies, respectively. c GRT-1 GR log and borehole image log showing unrolled vertically compressed image of the sedimentary cover-basement transition in GRT-1. This acoustic log presents the amplitude data, highlighting natural fractures (Grès d’Annweiler) and induced fractures (Grès Anté-Annweiler)

Back to article page