The drainage area of the Iberian Ranges (NE Spain) houses one of the most extensive Quaternary fluvial tufaceous records in Europe. In this study, tufa deposits in the Añamaza, Mesa, Piedra and Ebrón river valleys were mapped, stratigraphically described and chronologically referenced from U/Th disequilibrium series, amino acid racemization and radiocarbon methods. Tufa deposits accumulated in cascades, barrage-cascades and related damming areas developed in stepped fluvial systems. The maximum frequency of tufa deposition was identified at 120 ka (Marine Oxygen Isotope Stage [MIS] 5e), 102 ka (MIS 5c), 85 ka (~ MIS 5a) and 7 ka (MIS 1), probably under warmer and wetter conditions than today. Additional phases of tufa deposition appear at ~ 353 ka (~ end of MIS 11), 258–180 ka (MIS 7) and 171–154 ka (MIS 6). Although most tufa deposition episodes are clearly correlated with interstadial periods, the occurrence of tufa deposits during the penultimate glaciation (MIS 6) is remarkable, indicating that the onset of this stage was climatically favourable in the Iberian Peninsula. Biostatic conditions and the dynamics of karstic systems regulating tufa deposition seem to be sensitive to the precipitation regime, controlled by shifts in the position of North Atlantic atmospheric belts, and summer insolation, regulated by orbital forcing.

A C C E P T E D M A N U S C R I P TThese findings underscore the significance of accounting for both groundwater behaviour and rainfall stable isotope composition when interpreting climate parameters in carbonate systems, particularly when differences between the isotopic signatures of deposits exist in the same region.

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Thrusting at shallow depths often precludes analysis by means of structural indicators effective in other geological contexts (e.g., mylonites, sheath folds, shear bands). In this paper, a combination of techniques (including structural analysis, magnetic methods, as anisotropy of magnetic susceptibility and paleomagnetism, and paleothermometry) is used to define thrusting conditions, deformation, and transport directions in the Cameros–Demanda thrust (North Spain). Three outcrops were analyzed along this intraplate, large-scale major structure having 150 km of outcropping length, 30 km of maximum horizontal displacement, and 5 km of vertical throw. Results obtained by means of the different techniques are compared with data derived from cross sections and stratigraphic analysis. Mixed-layer illite–smectite and vitrinite reflectance indicating deep diagenetic conditions and mature stage of hydrocarbon generation suggests shallow depths during deformation, thus confirming that the protolith for most of the fault rocks is the footwall of the main thrust. Kinematic indicators (foliation, S/C structures, and slickenside striations) indicate altogether a dominant NNW movement of the hanging wall in the western zone and NE in the eastern zone of the thrust, thus implying strain partitioning between different branches of the main thrust. The study of AMS in fault rocks (nearly 400 samples of fault gouge, breccia, and microbreccia) indicates that the strike of magnetic foliation is oblique to the transport direction and that the magnetic lineation parallelizes the projection of the transport direction onto the kmax/kint plane in sites with strong shear deformation. Paleomagnetism applied to fault rocks indicates the existence of remagnetizations linked to thrusting, in spite of the shallow depth for deformation, and a strong deformation or scattering of the magnetic remanence vectors in the fault zone. The application of the described techniques and consistency of results indicate that the proposed multidisciplinary approach is useful when dealing with thrusts at shallow crustal levels