Fig. 6

Halite and clay to marl lithofacies shown in 360° core scans. A Almost pure halite with slight color banding. Stadel-3, 1147.00–1147.63 m, «Untere Salzschichten». B Reddish halite with thin seams of anhydritic marl (arrows, LF 16a) above a marl bed with anhydrite nodules and halite cubes (determined separately as LF 20). The relatively coarse-grained halite (grain size up to 1 cm) was probably recrystallized whereby the seams were slightly blurred. The deposition of the seams was probably accompanied by dissolution processes, so that the base of the seams extends into the halite underneath whereas the top of the seams is sharply defined. Stadel-2, 1175.75–1176.03 m, «Untere Salzschichten». C Coarse crystalline halite (crystal size > 1 cm) with thin seams and layers of anhydritic marl. The two layers show an internal structure with anhydrite nodules, which may indicate a comparatively longer interruption of halite precipitation and desiccation. The deposition of the two layers was probably associated with dissolution processes in the underlying halite. Therefore, the base of the layers partially extends into the underlying halite (arrows) whereas the top is sharp. Recrystallization of the halite led to blurring and partial breaching of both the layers and the seams. Stadel-2, 1152.33–1152.33 m, «Untere Salzschichten». D Floatbreccia in halite matrix. Components consist of clayey lithologies, some with anhydrite nodules, suggesting at least temporarily desiccated mudflat as an origin. The series is cut at the top by a distinct (subaerial) dissolution horizon (arrows) above which wrinkly laminated anhydrites (LF 1a) indicate a microbial mat facies. Bülach-1-1B, 1258.31–1258.94 m, «Untere Salzschichten». E Coarse crystalline halite (crystal size up to 4 cm) with argillaceous anhydrite filling the intercrystalline space. The shape of the fine-grained clayey anhydrite is pre-conditioned by the largely cubic halite crystals. The texture can be interpreted as a product of recrystallization of the halite, during which the growth of the halite crystals led to a displacement of the anhydritic sediment. Stadel-3, 1175.50–1175.78 m, «Untere Salzschichten». F Fine to coarse crystalline halite with ductile-deformed and fractured marl and anhydrite fragments. Some of the non-halite fragments show internal structures (lamination and nodules). Hypidiomorphic halite crystals occur in some of the fragments (arrows). Bülach-1-1B, 1252.53–1252.82 m, «Untere Salzschichten». G Anhydritic marl with anhydrite nodules and brecciated clay fragments underlying coarse crystalline halite with intercrystalline marl (LF 18). Within the anhydritic marl at the bottom, hypidiomorphic, mainly reddish, halite crystals have grown. Towards the base, the marl layer grades into 'chicken-wire' anhydrite (LF 5). Whether the halite cubes within the marls formed due to the recrystallization in the overlying halite, which has coarsened the crystal size, or if they grew previously in the freshly deposited sediment, cannot be deciphered with certainty. Bülach-1-1B, 1178.76–1179.05 m, base of «Untere Salzschichten». H Anhydritic marl layer with anhydrite nodules intercalated into the halite succession. The layer is fractured, the resulting fissures are filled with fibrous halite (arrow), probably crystalized during opening of the fissures. Part of the layer has collapsed into what appears to be intermittent plastic salt and now forms a floatbreccia within the halite (LF 17). The salt filling the resulting cavity and occurring around the collapsed components is reddish, indicating oxidizing conditions. Bülach-1-1B, 1257.38–1257.67 m, «Untere Salzschichten». I Marl layers, each with dolomite content increasing upward. Layering resulted from repetitive variations in the ratio of clay input to carbonate precipitation and shows a transition from a clay-dominated to a dolomite-dominated system. Diagenetic anhydrite nodules are intercalated at the bottom of the picture. Marthalen-1, 949.77–950.05 m, «Obere Sulfatzone» («Übergangsschichten» to «Dolomit-dominierte Schichten»). J Layered dark clay layer overlying a nodular anhydrite (LF 7). From landward source area, clay may be transported by repeated sheet floods, which could have formed the sharp erosion surface at the base of the clay layer. Bözberg-1-1B, 916.44–916.72 m, «Untere Sulfatzone»