Well-preserved SSE-dipping low-angle normal faults (LANF) active during the Early Permian (Cisuralian) were recognized along the northern margin of the Orobic Basin (central Southern Alps, N Italy). These faults, which escaped most of the Alpine deformations, exhumed the Variscan basement during the deposition of the upper part of the Lower Permian succession (Pizzo del Diavolo Formation). Fault planes show evidence of frictional processes typical of the upper crust associated with hydrothermal circulation, responsible for the deposition of cm to m thick tourmalinite and Uranium mineralization.The recognized LANFs interacted with high-angle normal faults producing half grabens that stored the Lower Permian deposits, where synsedimentary fault activity in their hangingwall is testified by abrupt vertical and lateral facies changes, thickness variations and by soft-sediment deformations.Mesoscopic structures, exposed in the hangingwall of a major LANF (the Aga-Vedello Fault system) along a synthetic high-angle normal fault, include conjugate normal faults, horst-and-graben, domino-

Managed aquifer recharge (MAR) refers to a suite of methods by which excess surface water or non-conventional water is stored underground for subsequent recovery or environmental purposes. MAR solutions have been largely used in unconsolidated aquifers, while their application in karst aquifers is rare. This research presents the first results of a MAR viability study on the island of Vis, a small karstic island in the Adriatic Sea. Favorable geological and hydrogeological conditions enable the formation of karst aquifers, making the island autonomous in terms of water supply. The island’s main aquifer, exploited in the Korita well field, is protected from seawater intrusion by several hydrogeological barriers. However, climate change and high seasonal pressures related to tourism pose a threat to the future availability of freshwater. Multidisciplinary field and laboratory investigations were carried out to detail the geological and hydrogeological setting of the island and its groundwater resource. Field analyses consisted of groundwater monitoring and sampling, geophysical investigations (i.e., electrical resistivity tomography), and structural measurements. Laboratory analyses included measurements of principal cations and anions and tritium activity. Despite low precipitation during the observation period (September 2019 - December 2020), the groundwater resource at the Korita site showed stable trends of physico-chemical parameters with a good storage potential and a long-term reserve. Geophysical investigations evidenced a relatively homogeneous sequence of the rock mass at a larger scale, while structural analyses indicated the occurrence of E-W karstified and open fractures that could represent a preferential flow path in the carbonate aquifer. A MAR solution for the Vis island was proposed combining an infiltration pond scheme with the direct injection of the accumulated waters into the aquifer using available wells. The potential water source could be represented by the runoff collected in an old artificial channel and the associated pond system in Korita.

Fluid sources and migration pathways can dramatically change during the multiphase tectonic evolution of thrust wedges. We present a multidisciplinary study of syntectonic calcite cements in the Lower Cretaceous carbonates of the external Bornes (SE France), which underwent sub-aerial exposure during flexural bulging, layer-parallel shortening, folding, and post-folding oblique contraction. Based on stable and radiogenic isotopes, trace elements, fluid inclusion and clumped isotopes thermometry, we identified two main paleofluid types. The older iron-rich calcite cements, associated with the pre-folding and early syn-folding stages, precipitated from an 18O-enriched fluid (δ 18O = +8.6 - +11.6 ‰ VSMOW) at temperatures between 90 and 115 °C. The younger calcite cements, associated with the late syn-folding and post-folding oblique contraction stages, have low iron content and precipitated from an 18O-depleted (δ 18O = -7.5 - -4.3 ‰ VSMOW) meteoric fluid at temperatures between 40 and 80 °C. The older fluid reached thermal equilibrium with the host rock at the maximum burial conditions, while the second one was likely heated in the inner sector of the belt before migrating towards the foreland. 87Sr/86Sr ratios exclude any contribution from basement-derived ascending fluids, pointing to the migration of meteoric fluids within the laterally continuous fractured Cretaceous units.Supplementary material:https://doi.org/10.6084/m9.figshare.c.5882212

Deformation patterns in shallow crustal sectors exhumed at mountain fronts typically record evolutionary pathways that mostly occurred in the subsurface of foreland basin systems, where deformation and sedimentation commonly interact (DeCelles & Giles, 1996). Thrust-related fold growth is controlled by two major factor categories (e.g., Tavani, Storti et al., 2015), namely: (a) stress field and environmental conditions of deformation; (b) mechanical stratigraphy and structural inheritance of deformed multilayers.Regional stress fields driving deformation in foreland basin systems are influenced by both internal and external factors. The former include: (a) the local tectonic regime, with typically extensional regimes in the back-bulges, forebulges and outer foredeeps, replaced by contractional regimes in inner foredeeps and thrust wedge toes; (b) the thickness of syn-orogenic sediments in foredeeps; (c) the along strike pattern of uplift and subsidence in forebulges and foredeeps, respectively (e.g., Tavani, Storti et al., 2015). External factors, which typically derive from tectonic plate interactions at convergent margins, include the occurrence of rigid indenters and block rotations about vertical axes, and variations through time in convergence directions and rates (e.g.,

<p>The study of fault damage zones is key to the understanding of fault-related fluid flow in the upper crust with many applications, including groundwater and hydrocarbon exploration, and underground storage of CO<sub>2</sub> and H. Many studies reveal that a relationship exists between fault damage zone width and net fault displacement. Despite this positive relationship, several factors such as the tectonic setting, the depth of deformation, the deformation mechanisms, and the evolving mechanical properties of fault rocks affect damage zone characteristics (e.g., width, asymmetry, fracture attitude, deformation intensity). Furthermore, recent studies show that the overall along-strike fault geometry may play a pivotal role in controlling damage zone characteristics. In particular, areas such as tip regions, linkage sectors, relay ramps and step-overs can be characterised by fault damage zone parameters markedly different from sectors away from these structural complexities. In this contribution, we present new structural data of fault damage zone parameters acquired along the 8 km long extensional Kornos-Aghios Ioannis Fault (KAIF) on Lemnos Island, North Aegean Sea, Greece. The KAIF deforms lower Miocene effusive and hypabyssal magmatic rocks and middle Eocene to lower Miocene turbidites. Deformed rock volumes along the KAIF are locally strongly altered by hydrothermal fluids (e.g., hydrothermal silicification). We provide a detailed characterization of the KAIF in terms of 2D fault geometry (mapped at 1:1000 scale) and kinematics and we present a characterization of fault damage zone parameters, including frequency and attitude of subsidiary fault-related fractures, in different fault sectors. The acquired data allowed us to define the boundaries of fault damage zones in the different sectors and to discuss the differences in terms of fracture attributes in linking- and tip-damage zones compared to damage zones away from these structural complexities. Our results show that fault damage zones in linkage and tip sectors are wider and that fault-related fractures are more clustered around several subsidiary faults with centimetre- to metre-offsets. Also, secondary fractures in linkage and tip sectors are less systematically oriented, thus increasing fracture network connectivity and, consequently, facilitating fluid mobility in structurally complex fault sectors.</p>