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

Abstract

U-Pb dating using laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS), δ13 C, δ18 O, clumped isotopes and 87 Sr/ 86 Sr 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 migrat- ing 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 brit- tle 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 in- tegration of these data is also used to compare the fluid flow evolution of the Southern Pyrenees with that of other oro- gens worldwide and to generate a fluid flow model in fold and thrust belts. At a more local scale, the U-Pb dataset pro- vides 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 ma- rine sediments and magnetostratigraphy of continental de- posits.