Geochronological and geochemical data from fracture-filling calcites from the Lower Pedraforca thrust sheet (SE Pyrenees)

U-Pb dating using laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS), δ13C, δ18O, clumped isotopes and 87Sr/86Sr analysis, and electron microprobe have been applied to fracture-filling calcites and host carbonates from the Lower Pedraforca thrust sheet, in the SE Pyrenees. These data are used to determine the type and origin of migrating fluids, the evolution of the palaeohydrological system and timing of fracturing during the emplacement of this thrust sheet, as described in the article “From hydroplastic to brittle deformation: controls on fluid flow in fold and thrust belts. Insights from the Lower Pedraforca thrust sheet (SE Pyrenees)” – Marine and Petroleum Geology (2020). The integration of these data is also used to compare the fluid flow evolution of the Southern Pyrenees with that of other orogens worldwide and to generate a fluid flow model in fold and thrust belts. At a more local scale, the U-Pb dataset provides new absolute ages recording the deformation in the Lower Pedraforca thrust sheet, which was previously dated by means of indirect methods such as biostratigraphy of marine sediments and magnetostratigraphy of continental deposits.

evolution of the Southern Pyrenees with that of other orogens worldwide and to generate a fluid flow model in fold and thrust belts. At a more local scale, the U-Pb dataset provides new absolute ages recording the deformation in the Lower Pedraforca thrust sheet, which was previously dated by means of indirect methods such as biostratigraphy of marine sediments and magnetostratigraphy of continental deposits.
© 2020 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY license.

Value of the data
• This data set provides new insights of the relationship between fluid flow and deformation in the SE Pyrenees during a particular period of their tectonic history. • This data is of interest for geoscientists studying the relationships between fluid flow and deformation in fold and thrust belts and those working in the geochronology of the SE Pyrenean deformation. • This data and their comparison with datasets from other orogens worldwide are useful to perform general models of fluid flow in fold and thrust belts. • The clumped isotopes data provide evidence of the dominant thermal regime in the Lower Pedraforca thrust sheet during deformation, which can be used as analogue for similar deformed areas that are under geothermal exploration.

Data description
Data were obtained from 57 representative samples of six different host rocks and eight types of calcite cement (Cc1 to Cc8) precipitated in seven types of fractures (F1 to F7). The location of these samples is shown in Table 1 . The main features of fractures and calcite cement and host rocks are described in [1] .
The U-Pb dating of calcite cement Cc3, Cc4, Cc6, Cc7, and Cc8 was applied by LA-ICPMS on 12 samples. From these, nine dates ranging from 47.9 ± 1.3 to 42.3 ± 0.8 Ma were obtained from 240 spot analyses ( Table 2 ). Tera-Wasserburg plots in Fig. S1 from the supplementary material of [1] show the presence of variable amounts of common and radiogenic lead that correlate well with the Pb-U, yielding for most samples well-defined regression lines with MSWD (mean square weighted deviation) of < 2. Uncertainties (2 σ ) of most analysis spots are low (small circles), and the uncertainties (2 σ ) of the lower intercept ages range from 0.7 to 2.0 Ma (1.5 and 6.6%). Samples for which the U-Pb dating method failed are characterized by high common lead and low uranium contents. The raw data of U-Pb analyses are presented in the supplementary material of [1] .
From the LA-ICPMS method used for U-Pb dating, the U and Pb content of calcite cement Cc3, Cc4, Cc6, Cc7, and Cc8 also were measured ( Table 2 ). For Cc3, the U and Pb content range from 0.005 to 0.813 ppm and from below the detection limit to 0.019 ppm, respectively ( n = 51). The U content for Cc4 range from 0.022 to 1515 ppm and the Pb content from 0.001 to 0.217 ppm ( n = 53). For Cc6, the U and Pb content range from 0.077 to 3253 ppm and from 0.001 to 1388 ppm, respectively ( n = 59). The U content for Cc7 range from 0.084 to 6502 ppm and the Pb content from 0.002 to 0.35 ppm ( n = 56). For Cc8, the U and Pb content range from 0.023 to 1817 ppm and from 0.01 to 0.144 ppm, respectively ( n = 21).
The δ 13 C and δ 18 O composition of calcite cement Cc1 to Cc8 is already presented in [1] .
Mean value and standard deviation of these results is presented in Table 3 . Cc2 has the low-   [2] . The 87 Sr/ 86 Sr was measured in calcite cement Cc3, Cc5 and Cc6 and of one sample of Upper Cretaceous limestones. Analyses provide ratios from 0.707817 to 0.708230.
The Mg, Sr, Fe and Mn content in ppm of calcite cement Cc1, Cc3, Cc4, cc5, and Cc6 was determined through 170 electron microprobe spot analyses presented in [1] . The mean content and the standard deviation of the elemental composition of each cement is presented in Table 4 . Cc5 has the lowest Mg mean content (1790 ppm), whereas Cc1 has the lowest value (3999 ppm).

Experimental design, materials and methods
The methods and analytical protocols followed for the geochronological and geochemical analysis of samples is the same described in [1] . Prior to these analyses, petrographic observations of 57 polished thin sections made from host rocks and fracture-filling calcite cement were made using optical and cathodoluminescence microscopy. A CL Technosyn cathodoluminescence device Model 8200 MkII at 15-18 kV operating conditions and 350 μA gun current was used to distinguish the different types of cement.
U-Pb dates were acquired using laser ablation-inductively coupled plasma mass spectrometry (LA-ICPMS) at FIERCE (Frankfurt Isotope and Element Research Center, Goethe Universität). Each analysis consisted of 18 s of background acquisition followed by 18 s of sample ablation and 25 s of washout. Prior to analysis, each spot was pre-ablated with 8 laser pulses to remove surface contamination. Soda-lime glass NIST SRM 614 was used as a primary reference together with three carbonate reference materials. Raw data were corrected offline using an in-house VBA spreadsheet program [ 3 , 4 ]. Due to the carbonate matrix, additional offset factors were applied, which were determined using WC-1 carbonate reference material [5] . A stromatolitic limestone from the Cambrian-Precambrian boundary in South-Namibia (here called NAMA) was analysed and used as a secondary in-house RM for quality controlData were plotted in Tera-Wasserburg diagrams and ages were calculated as lower intercepts using Isoplot 3.71 [6] . All uncertainties are reported at the 2 σ level.
For δ 13 C and δ 18 O analysis of calcite cement and carbonate host rocks, a 400 μm-thick dental drill was employed to extract 60 ± 10 μg of carbonate powder from trims. The calcite powder was reacted with 100% phosphoric acid for 2 min at 70 °C. The resultant CO 2 was analysed using an automated Kiel Carbonate Device attached to a Thermal Ionization Mass Spectrometer Thermo Electron (Finnigan) MAT-252. The International Standard NBS-18 and the internal standard RC-1, traceable to the International Standard NBS-19, were used for calibration. The results were corrected with respect to the VPDB (Vienna Pee Dee Belemnite) standard. Standard deviation is ± 0.02 ‰ for δ 13 C and ± 0.05 ‰ for δ 18 O.
For clumped isotopes thermometry, 2-3 mg aliquots of powdered carbonates were measured with the Imperial Batch Extraction system (IBEX), an automated line developed at Imperial College of London. Each sample was dropped in 105% phosphoric acid at 90 °C and reacted for 30 min. The reactant CO 2 was separated using a poropak-Q column and transferred into the elbows of a Thermo Scientific MAT 253 mass spectrometer (Thermo Fisher GmbH, Bremen, Germany). The post-acquisition processing was completed with a software for clumped isotope analysis named Easotope [7] . 47 values were corrected for isotope fractionation during phosphoric acid digestion employing the method of [8] . The data were also corrected for non-linearity applying the heated gas method [9] and projected into the absolute reference frame of [10] . Samples were measured three times and the average result was converted to temperatures using the calibration method of [11] . Carbon-coated polished thin sections were used to analyse major, minor, and trace element concentrations on a CAMECA SX-50 electron microprobe. The microprobe was operated using 20 kV of excitation potential, 15 nA of current intensity and a beam diameter of 10 μm. Analytical standards included natural silicates, carbonates and oxides as follows: calcite (Ca), dolomite (Mg), Fe2O3 (Fe), rhodonite (Mn) and Celestite (Sr). The detection limits were 135 ppm for Mn, 127 ppm for Fe, 101 ppm for Ca, 146 ppm for Na, 180 ppm for Mg, and 390 ppm for Sr. Precision on major element analyses averaged 0.64% standard error at 2 σ confidence levels.

Declaration of Competing Interest
The authors declare that they have no known competing financial interests or personal relationships which have, or could be perceived to have, influenced the work reported in this article.