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This study aims to reconstruct the evolution of fractures in a well-exposed thrust zone in the southern Pyrenees, and to qualitatively evaluate the thrust zone permeability. This is, to characterize the transfer of fluids through the fault zone and to qualitatively determine the fault behavior as conduit or barrier to fluid flow. This contribution combines: (i) field structural data including bedding and fracture orientation and dips, fracture type and kinematics, and crosscutting relationships; (ii) Petrographic characterization of thin sections using optical and cathodoluminescence microscopes, and (iii) geochemical analyses applied to calcite veins, fault rocks and host rocks including ¿ 18 O, ¿ 13 C, 87 Sr/ 86 Sr, clumped isotopes and trace elements.

The petrophysical and petrothermal characterization of the sedimentary succession of the Oliana anticline in the Southern Pyrenees has been performed on the basis of mineral density, connected porosity, permeability, P-wave velocity and thermal conductivity measurements of rock samples distributed along this anticline. This dataset was used to explain: (I) the variability of petrophysical rock properties along the Oliana anticline, (II) the distribution of thermal conductivity along the sedimentary units of the anticline, (III) the relationships between the fold and petrology concerning the mineral density, connected porosity, permeability, P-wave velocity and thermal conductivity of rocks and (IV) the tectonic and diagenetic controls underlying the observed relationships, as described in the research article: "Petrological, petrophysical and petrothermal study of a folded sedimentary succession: the Oliana anticline (Southern Pyrenees), outcrop analogue of a geothermal reservoir - Global and Planetary Change Journal (2023)¿. This contribution presents here the raw and statistical datasets used to discuss the potential of the Oliana anticline as a geothermal reservoir analogue and also includes an extended methodological section that proposes a new procedure to measure the thermal conductivity of highly heterogeneous coarse-grained sedimentary rocks using the Modified Transient Source Plane (MTPS) method on a TCi C-Therm thermal analyzer. These complete datasets can be used to better discuss and understand the principal limitations of outcrop analogue studies applied to unconventional geothermal reservoirs in foreland basins on the basis of the analysis of rock petrophysical and petrothermal properties. Furthermore, the data obtained in the Oliana anticline can be used to understand the structural, diagenetic and petrological factors that can modify the petrophysical and petrothermal properties of rocks and to discuss the potential of foreland basin margins to be us

In the Upper Pedraforca thrust sheet in the Southern Pyrenees, replacive dolomite occurs in the Jurassic car bonates (Rd1) and Lower Cretaceous sedimentary breccias and carbonates (Rd2). Dolomite crystals are red dull to non-luminescent, subhedral, 15- 400 ¿m in size, and show idiotopic and hypidiotopic textures. The replacive dolostones are cut by fracture-filling dolomite cement (Dc1 and Dc2). Dc1 precipitated in bed-per breccia clasts and in bed-parallel fractures and composed of non- to red-luminescent saddle crystals of 250 ¿m and 2 mm in size, respectively. The 87Sr/86Sr ratio of Rd1 (0.707816) is higher than that of Jurassic-Cretaceous seawater, suggesting siliciclas tic inputs, whereas the ratios of Rd2 (from 0.707366 to 0.707604) are within the range of the Late Jurassic Early Cretaceous seawater. The bell-shaped to almost flat REE+Y patterns of Rd1 and Rd2 and the positive Y and Gd anomalies reflect marine influence. The Y/Ho ratios of 52.75- 44.91 reflect intermediate values be tween the composition of marine carbonates and detritic sediments. The absence of positive Eu anomalies discards high-temperature dolomitization. Fracture-filling dolomites have temperatures of 149.4 ± 12.5 oC and ¿18Ofluid of +11.2 ± 1.1 ¿ VSMOW for Dc1 and 124.7 ± 6.2 oC and +7.1 ± 0.7 ¿ VSMOW for Dc2, reflecting the influence of formation brines possibly interacting with the Triassic evaporites. Rd1 and Rd2 share a common origin and age with shallow burial dolostones from the North Pyrenean Zone. Contrarily, fracture-filling dolomites in the Southern Pyrenees precipitated from formation brines, whereas deep-crustal and mantle-derived fluids (from 250 to >300 oC) were also identified in the Northern Pyrenees. These differences are interpreted as higher crustal thinning in the North Pyrenean Zone than in the Southern counterpart, facilitating the occurrence of deep-sourced fluids and high-temperature/low-pressure metamor- phism

Dating fold-related structures is critical to understand the timing, duration, and rate of fold growth as well as the sequential evolution of fold-and-thrust belts. In this contribution, we combine structural analysis of fractures with U-Pb dating of calcite veins related to the evolution of the Bóixols-Sant Corneli anticline (Southern Pyrenees) aiming to constrain the age and evolution of deformation and the duration of folding. Twenty-three U-Pb ages were obtained in the different sets of fracture-filling calcite veins, which span from Late Cretaceous to late Miocene (79.8 ± 1.2 Ma to 9 ± 4.6 Ma). These ages have been attributed to growth (71.2 to 56.9 Ma), fold tightening (55.5 to 27.4 Ma) and collapse (20.8 to 9.0 Ma) of the Bóixols-Sant Corneli anticline. This reveals a duration of 14 Myr for the folding stage and 28 Myr for the fold tightening, which translates in 42 Myr of the entire folding process and thus encompassing most of the Pyrenean compression.