This study presents a multidisciplinary investigation of the Bolle della Malvizza mud volcanoes, located in the southern Apennines fold-and-thrust belt (Italy), aimed at characterizing these structures and constraining processes and sources of mud and gas leakage. Twelve main vents are present, continuously and slowly ejecting mud, saltwater, and gases, including CH4 and CO2. We carried out different investigations, including (i) stratigraphic and structural surveys, (ii) topographic and morphometric evaluations using a digital elevation model obtained by drone photogrammetry, (iii) geochemical measurements of CO2 flux, radioactivity and soil pH and (iv) geophysical surveys including electrical resistivity tomography, induced polarization and self potential. Nine main groups of mud volcanoes are present in the area, varying in size (from a few centimeters to 13 meters) and height (from ∼3 to 15 cm). These mud eruptive vents are aligned along the ENE-WSW and N-S directed normal faults. The geogenic CO2 flux is low when compared to other non-volcanic emissions in the southern Apennines. The electrical resistivity tomography reveals conductive volumes interpreted as clay-rich layers alternating with resistive bodies of clay-marly rocks, and conductive layers corresponding to shallow and deep aquifers. The induced polarization data highlights high-chargeability zones linked to clay-rich bodies and a narrow vertical conduit connecting deeper conductive zones to shallow levels. Self-potential data show a pronounced negative anomaly aligned with the main vents, spatially matching the high-chargeability conduit and a resistivity inflexion in the electrical section. Ground deformation modelling and Monte Carlo simulation suggest a source at ∼110 m depth, with a negative volume change of ∼5 × 105 m3. We propose a conceptual model in which deep fluids slowly ascend along damage zones of two major faults, interacting with the surficial aquifer and the clayey host rock, and accumulate in a shallow reservoir that gradually releases muddy fluids to the surface, forming mud volcanoes that are continuously eroded during rainfall events.

Nested structures are a common feature of large calderas, but scientists often infer their existence only through indirect observations, as later eruptive deposits cover the ring-fault zones that bound the different collapsed blocks. The inherent structural complexity of caldera systems makes them challenging to investigate directly. The Island of Ischia (southern Italy) provides a unique opportunity to examine caldera-related structures, such as ring faults and dykes, because block resurgence has uplifted the caldera floor, exhuming its deepest rocks and structures. Due to the dramatic landslide that occurred in 2022 at Casamicciola, a series of previously unobserved dykes hosted in the Mt. Epomeo Green Tuff deposits (MEGT, 62-56.5 ka) were exposed, offering an extraordinary opportunity to study their geometries, intrusion mechanisms, and petrological significance in relation to the dynamics of caldera-forming eruptions. These dykes, located along the northern slope of Mt. Epomeo, situated in the central part of the island, exhibit various shapes, including ball-chained structures, ramp-flat geometries, and orthogonal strands. They are cm-thin and meters long, intruding in the pyroclastic deposits of the intermediate part of MEGT. A notable feature is the presence of a cataclastic shell that encases the cores, composed of fragmented tuff and crystals within a glassy matrix. Petrological and geochemical analyses indicate that the dyke compositions are consistent with those of the Monte Epomeo Green Tuff (MEGT) eruption, thereby linking them to the last phase of the caldera-forming eruption. Our findings unravel the connections between these dykes and the MEGT eruption, identifying this fault zone as a ring-fault zone of the MEGT caldera and, in turn, providing new insights into the nested caldera structure of Ischia Island and the role of the ring-fault zone during subsequent block resurgence. We propose a model for the origin of the dykes, involving localized volatile-poor injections approaching the surface from a larger feeder dyke that fed the MEGT eruption. These structures, together with the deformation structures identified in the marine deposits beneath the tuff sequence, provide compelling evidence that this area represents a segment of the MEGT caldera ring-fault zone formed during the caldera-forming eruption, and that caldera block-resurgence has been accommodated by the inversion of this ring-fault zone.

Campi Flegrei (southern Italy) has produced >70 eruptions in the last 15 kyr and is currently showing significant signs of unrest within a densely populated part of Europe. These eruptions span a wide range of eruptive styles and compositions and have erupted from different vent locations within a larger caldera system. Here, we characterised the oxygen, strontium, neodymium, and lead isotopic composition of mineral and glass separates from post-15 ka Campi Flegrei eruptions, alongside basement rocks which may have contaminated the magmas, to investigate whether interaction between magma and country rock varies across the caldera. Our data point to an important role of assimilation in the system, with differences between individual eruptions attesting to variation in the lithology and amount of assimilated material. These differences correlate with the vent location within the caldera; eruptions along northern/eastern caldera rim faults have isotopic compositions which deviate further from typical mantle source values than those erupted from the centre of the caldera or along western caldera rim faults. Comparison with the isotopic composition of the basement rocks suggests small amounts (<10%) of Palaeozoic metamorphic basement contaminated the eruptions from northern/eastern caldera rim faults, whereas more extensive (<30%) interaction with syenitic cumulate residue (i.e. pre-existing magma mush) affected the isotopic composition of eruptions from the centre and west of the caldera. Our results from vents located across the caldera provide new insights and further constraints on processes operating in the sub-volcanic magmatic system beneath Campi Flegrei prior to an eruption.

Abstract Caldera systems commonly experience inner resurgence, which shapes patterns of volcanic activity. However, incomplete reconstructions of past ground deformation can lead to incorrect recognition of precursory signals. The Campi Flegrei caldera (Italy) provides an exceptional opportunity to address this issue as uplifted marine sediments interlayered with pyroclastic deposits preserved repeated Holocene deformation. Here, we reassess the mechanisms and evolution of caldera resurgence at Campi Flegrei by integrating previous data sets with new observations from the submerged sector, providing improved spatial and temporal constraints. We document ∼190 m of permanent uplift over the last 10.5 kyr, expressed as a ∼9‐km‐wide, bell‐shaped pattern centered on the city of Pozzuoli. This pattern is best explained by the incremental growth of a resurgent dome controlled by magma emplacement at ∼3–4 km depth in a stacked‐sill configuration. Our reconstruction shows that, since resurgence began at 10.5 ka, the volume of shallow intruded magma has been approximately three times greater than the erupted volume, implying dampened eruptive activity. Nevertheless, temporal overlaps between uplift phases and eruptions indicate a direct link between magma transfer and unrest. Resurgence has also marked the inward migration of eruptive vents and the eruption of more silicic magmas, reflecting a major reorganization of the magmatic system. Localized deformation anomalies that deviate from the main displacement pattern are related to localized intrusions and fault reactivation. These findings identify Campi Flegrei as a resurgent dome system tightly connected to the dynamics of present‐day unrest, which may represent the early stage of a renewed eruptive period.

Studying fault zone properties is crucial in addressing key challenges in subsurface exploration, resource management, and seismic risk evaluation. As global interest in geothermal energy, hydrogen, and carbon storage intensifies, the mechanical and structural characterization of faults, as well as their impact on fluid migration, reservoir integrity, and fault sealing analysis, is becoming increasingly important. The presented study focuses on the structural and mechanical properties of superposed fault zones in dolostones, an issue that has been poorly investigated. In particular, we addressed how the architecture of an earlier, large-scale normal fault (F1) influences the geometry and deformation mechanisms of younger, superposed strike-slip faults (F2). The F1 fault consists of four sub-parallel fault rock units, each several tens of meters thick: (i) a cataclastic core (Cu), bounded in the hanging wall by (ii) cemented micro-mosaic breccia (MB), and in the footwall by (iii) high-strained (HS) and (iv) low-strained (LS) fault rocks. To achieve this aim, we performed some geotechnical and morphometric analyses. Uniaxial compressive strength (UCS) tests revealed mean values of 83 MPa and 120 MPa for MB and LS, respectively, whereas Cu and HS exhibit lower UCS values of 58 MPa and 62 MPa, respectively. MB and Cu exhibit heterogeneous particle size distributions (PSD) and porosities of 4.02% and 4.96%, respectively, while HS and LS show more homogeneous PSDs with porosities of 2.87% and 2.19%, respectively.The F2 faults developed a spectrum of structural facies such as cataclastic shear bands (CSBs) in the LS and HS, and as compaction bands (CBs) in the MB and Cu. In the LS, cataclasis is highly localized within widely spaced, thick, tabular, and cemented CSBs. In the HS, deformation occurs through anastomosing CSBs, accommodating diffuse cataclasis and dissolution-precipitation mechanisms. In the Cu, anastomosing CBs develop through pore collapse and dissolution-precipitation processes. In the MB, compaction is driven by pore collapse and grain crushing, forming well-localized, widely spaced CBs.Overall, the microstructural properties (PSD and porosity) and mechanical strength of the F1 fault rocks are key factors influencing the deformation mechanisms (cataclasis vs. compaction) and the geometry (localized vs. anastomosing) of the F2 faults. These findings contribute to the understanding of fault permeability and fluid flow dynamics in multi-faulted dolomite reservoirs.

The Roccamonfina volcano, located in the Garigliano Graben, is the most long-lived volcano along the Tyrrhenian margin of the southern Apennines, with recorded activity through the Middle–Late Pleistocene. The lack of estimates about the timing and extent of graben-bounding fault activity hinders a thorough reconstruction of its evolution. In this study, we have conducted a comprehensive investigation into the magmatic dykes hosted within the carbonate rocks of the nearby Mt Cesima ridge. Combining new geochronologic data with borehole and topographic data, we provide quantitative estimates of displacements along graben bounding faults. Our results suggest that the volcanic activity was regulated by tectonic extension rates, marking the shift from early regional fissure swarms and building of the stratovolcano to climax in tectonic extension producing the uplift of the graben-bounding carbonate reliefs, potentially inducing the gravitational collapse of the main stratocone. The extensional tectonic activity decreased over time, which resulted in the decline of volcanic activity. The results of this study allow us to shed light on the timing of the fault activity controlling the shift from rift-like monogenetic fields to the formation of localized central volcanoes. Hence, the framework reconstructed here helps understanding of the onset and establishment of the volcanism in the Campania plain, whose early stage is concealed under the volcaniclastic cover.

Monogenetic eruptions characterize volcanic activity in caldera volcanic fields. One remarkable example is Campi Flegrei (southern Italy), which has experienced over 70 moderate-sized explosive eruptions in the past 15 k.y. Among these, only a few had a lateral propagation of the vent along an eruptive fissure. In this work, we explore the ca. 3.9 ka phreatomagmatic eruption of Nisida that occurred in the southeastern caldera ring fault zone. Combining field and uncrewed aerial vehicle (UAV)-based structural analysis with the available seismic reflection data, we traced the different stages of growth of a tuff cone complex along an similar to 1.4-km-long eruptive fissure. The eruption started within the ring fault zone and propagated first toward the northeast, and then toward the north-northeast, producing a dike-induced graben. We have evidence of multiple gravitational collapse events throughout the eruption, mainly accommodated by approximately west-northwest, south-dipping normal faults, and outward-dipping slip surfaces. An energetic maar-forming eruptive phase produced inward-dipping circumferential normal to transtensive faults accommodating the vertical collapse. Postlithification northeast-southwest and westnorthwest normal to left-lateral faulting possibly suggests the reactivation of the buried caldera rim in historical times. Features of fissure explosive eruptions, such as those observed here, are rarely reported in the literature. This case study thus offers an exceptional opportunity to examine syneruptive volcano-tectonic processes. Furthermore, we reassessed the volume of the eruption, including the dismantled morphology, yielding an unprecedented value of 0.17 km3 dense rock equivalent (DRE), with the subaerial extent now mostly eroded. Our results suggest that most of the eruptions of the last eruptive epoch (5.5-3.7 ka) had similar sizes (Volcanic Explosivity Index of 4) considering the single eruptive episodes. This work could prove useful for improving volcanic hazard assessment at the active Campi Flegrei, which represents the world's highest-risk volcanic area.

Campi Flegrei caldera (Naples, southern Italy) is one of the most hazardous volcanoes on Earth, having produced more than 70 eruptions in the past 15 kyr, and currently showing significant signs of unrest within a densely populated part of Europe. Post-15 ka eruptions span a range of eruptive styles and compositions, which broadly correlate with the spatial and structural location of vents within the large caldera: eruptions from vents along northern and eastern caldera rim faults are typically small and extend to mafic compositions; eruptions from vents in the central and eastern side of the caldera extend to evolved compositions and have produced Plinian columns; and vents along regional faults (also activated by caldera collapse) in the western caldera have produced sub-Plinian eruptions which are often relatively Na2O-rich and K2O-depleted. These compositional and eruptive differences suggest an intrinsic link between their volcano-tectonic setting and structure and/or processes operating within the sub-volcanic magmatic system. To investigate this, we compare post-15 ka erupted glass major element compositions to liquid lines of descent produced using the Rhyolite-MELTS thermodynamic model. To constrain magma storage conditions at Campi Flegrei, we systematically vary the crystallisation conditions in 1800 models before employing a new statistical approach to assess the quality of fit between natural glass compositions and model outputs. In simple (uncontaminated) fractional crystallisation models, we find that glass compositions in each volcano-tectonic setting are best reproduced by similar storage conditions: pressure of 110–160 MPa, liquidus oxygen fugacity of 0–1 log unit above the quartz-fayalite-magnetite buffer, and a liquidus H2O concentration of 2 wt% for northern, eastern and western caldera eruptions and 3 wt% for central caldera eruptions. However, the addition of an assimilant further improves the fit between predicted and observed major element compositions, with the amount and type of assimilant varying between volcano-tectonic settings. Best-fit models for vents along northern and eastern caldera rim faults include small (5–10%) amounts of Palaeozoic metamorphic basement, whereas those for vents in the centre of the caldera or along the western regional faults include larger quantities (~30%) of assimilated syenitic restite. The Fondi di Baia eruption is compositionally anomalous, and its evolution may reflect minor limestone or hydrothermal calcite contamination. Our results demonstrate a novel link between the spatial and structural location of vents within the Campi Flegrei caldera and the physicochemical processes operating within its magmatic system, providing important information for the assessment of future hazard scenarios.

In this work, we reconstruct the geometry and magma properties of the dyke that fed the Nisida eruption (~3.9 ka), located across the rim of the Campi Flegrei caldera (Italy). Results indicate that the magmatic overpressure was ~35 MPa, the dyke depth of origin was at ~5-6 km, consistent with petrologic studies, and the volume of the active magma chamber was 85-150 km3 with an upper bound of excess pressure rupture threshold of ~9 MPa. We show that a range between 4-9 MPa is common among the moderate-sized volcanic eruptions vented along caldera structures, suggesting a shared magma reservoir. Considering the volume change required to reach the rupture threshold, we simulate the ground deformation pattern triggered by such magma recharge, which produces a different and thus distinguishable geodetic signal compared to the currently observed one. This work may serve as a reference for identifying the transition from magma-driven unrest to volcanism at Campi Flegrei.

This study presents, for the first time in the southern Apennines (Southern Italy), evidence of fault-driven hydrothermal dolomitization during the late Triassic rifting of the western Adria Plate, through examination of fault-controlled saddle dolomite formation in Norian (Upper Triassic) dolomites, exposed in the western sector of the Matese Massif. This investigation focuses on dolomite breccias associated with N-S and NNW-SSE striking normal faults. These structures include layers of mature cataclasites made of clasts with angular boundaries within a highly porous matrix, crossed by veins, mosaic and chaotic breccias. The breccias consist of angular clasts of host rock dolomite, derived from the early marine replacive dolomitization of shallow-water carbonates, surrounded by coarse (ca. 500 mu m) saddle dolomite cement. The saddle dolomite cement is characterized by two distinct phases. The first phase (SD1) is yellow in color and inclusion-rich, forming a rim around the clasts. The second phase (SD2) is euhedral and exhibits well-defined zoning, with a transition from cloudy to limpid crystals. The saddle dolomite cement texture and the decreasing delta 18O and 87Sr/86Sr values suggest a precipitation temperature of about 100-120 degrees C from a fluid that might have interacted with a magmatic source. The U-Pb dating of the dolomite cement indicates a late Triassic crystallization age of approximately 206 +/- 13 Ma and 217.0 +/- 6.6 Ma. Furthermore, within the ferroan dolomite cement, quartz and hydrothermal minerals, notably fluorite and apatite, occur in minor quantities. These findings suggest that the brecciation and hydrothermal saddle dolomite precipitation were related to the activity of normal faults during Pangea breakup, resulting in the separation between the SW sector of Eurasia and the western margin of the Adria Plate. These data provide the first evidence of Triassic syn-tectonic saddle dolomites in this region of the Apennine belt and highlight the important role of U-Pb dating of fracture-filling dolomite cements in unraveling the tectonic evolution of structurally complex areas.

Studies of tectonic mélanges provide constraints on the evolution of active plate margins. However, resolving the pressure‐temperature trajectories of these deformed rocks, which are exhumed from low‐temperature conditions, can be challenging. We analyzed a Late Miocene‐Early Pliocene tectonic mélange formed in a shear zone in the southern Apennines (Basilicata, Italy), located in the hanging wall of a regional thrust, to provide estimates of temperature, pressure and strain. The mélange comprises slates with a fine‐grained phyllosilicate matrix embedding larger porphyroclasts with relict S 0 bedding. Electronic microscope analysis revealed a disjunctive cleavage (S 1 ), partially to fully transposed by a top‐to‐the‐E/SE crenulation cleavage (S 2 ) marked by white mica and chlorite. A late weak cleavage (S 3 ) is not accompanied by newly formed minerals. Kinematic vorticity analysis indicates a range of 20%–35% coaxial strain, whereas 3D strain analysis of deformed clasts suggests oblate strain. X‐Ray Powder Diffraction analysis of grains <2 μm indicates anchimetamorphic conditions between 200 and 250°C, with temperatures increasing by 50°C toward the thrust contact. Multi‐equilibrium modeling of coarser S 1 ‐S 2 grains ranges from 300 to 380°C, independent of their position in the shear zone. We attribute the low‐temperature range of finer grains to Apennine anchimetamorphism, whereas grains >2 μm are likely detrital and record higher pressure‐temperature conditions. Assuming a regional paleogeothermal gradient of 20°C/km, we estimate a maximum burial depth of about 12 km and a pressure of 0.32 GPa. This approach can be applied to similar contexts worldwide, providing a tool for regional tectonic reconstruction and process‐oriented studies.

The northern Calabrian ranges and the southern Apennines are part of a single orogenic segment of the Alpine chain system framing the central-western Mediterranean Sea. Three main tectonic complexes characterize this orogenic chain: (1) remnants of the overriding plate, including Variscan Paleozoic basement (Calabria-Peloritani terrane), which tectonically cover (2) an Alpine metamorphic belt, corresponding to an exhumed subduction channel, formed by slices of the Calabria-Peloritani terrane, meta-ophiolites (metamorphic Ligurian Units), and some successions of the continental Adria plate (downgoing plate), which are in turn superposed onto (3) a fold-and- thrust belt composed of remnants of an oceanic accretionary prism (nonmetamorphic Ligurian Units) on the top and an underlying imbricate orogenic pile consisting of shallow-water to pelagic continental Adria successions, also including buried shallow- water carbonates of the Apulian Platform. The exposed Apulian Platform domain (Puglia region) and the Adriatic Sea represent the current foreland. The orogenic chain results from the subduction of Ligurian Ocean lithosphere beneath the European plate/Calabria-Peloritani terrane starting during the Paleocene-Eocene. The restored mean tectonic vergences indicate that the thrust front migrated to the south in the Eocene-Langhian period, turning to the east during the Serravallian-Pleistocene interval. After the complete closure of the Ligurian Ocean in the Early Miocene, the subduction continued with the involvement of the continental part of the Adria plate, triggering crustal shortening until the middle Pleistocene. Complex geometries, reflecting the articulated paleogeographic domains formed by alternating shallow-water carbonate platforms and deep basins, controlled the shape of the thrust front-foredeep-forebulge system. Thin- and thick-skinned thrusting episodes have alternated during the orogenic shortening; however, since the early Pliocene, deepseated, ramp-dominated thrust faults have driven the crustal shortening, resulting in widespread envelopment thrusting, and out- of-sequence structures in the allochthonous wedge. The alternating different tectonic styles also resulted from the involvement in the subduction system of the continental Adria lithosphere, which is thicker under the carbonate platforms and thinner under the interspersed pelagic basins and the western margin facing the Ligurian Ocean. The involvement of thicker lithosphere during the subduction process caused two main backstops that triggered thick-skinned tectonics. The synorogenic sedimentation was ruled by the migration of the forebulge-foreland basin system, with flexure of the continental part of the Adria plate since the Oligocene and erosion of a large part of the Apennine and Apulian carbonates that fed the foredeep basins with calciclastic supply. Siliciclastic input, which originated from both the overriding plate and orogenic wedge, joined with orogenic volcaniclastics, marks the sedimentation in the foreland basin system, including the mature stage of the foredeep troughs and the wedge-top basins located on the top of the chain, with the latter also recording calciclastic sedimentation that originated from the erosion of the piled-up Adria carbonate successions.

We present a multidisciplinary study on natural non-volcanic CO2 degassing vents in the southern Apennines, aiming to investigate gas leakage mechanisms related to tectonic structures. The studied degassing areas are located in the Sele River Valley, north and east of Oliveto Citra town. The Sele River Valley features multiple cold and hot springs and frequently aligned gas vents emitting CO2 and noble gases. We performed structural-geological mapping and geochemical investigations (soil pH and CO2 mapping) in three key areas of the Sele River Valley. These were implemented by geophysical surveys, including 2D Electrical Resistivity Tomography (ERT), Induced Polarization (IP) Tomography, 2D Seismic Refraction Tomography (SRT), Magnetometry (MAG), and Self Potential (SP) mapping in a single sector (area 1) included in the Mofeta del Vecchio Mulino vents north of the Oliveto Citra town. The results of this multidisciplinary study indicate that most of the gas emissions are along the intersection between the major faults that crosscut a tectonic pile formed by limestones tectonically covered by an oceanic succession made of clays and marls. In area 1, ERT, IP, and SRT profiles mark a vertical conduit where the fluids migrate upward, corresponding to a major fault zone that lowered the tectonic pile to the north. The MAG and SP maps also show anomalies highlighting uprising fluids along the intersection between major faults. CO2 flux maps of three areas embedding the major vents show that the geogenic emissions are widespread, with the highest values reaching 2256 gm2d- 1. Generally, the degassing vents form about circular areas of 10 m in diameter. Also, the pH map indicates acid soil anomalies close to the major emission vents. The novelty of this work is the multidisciplinary approach, which uses different methodologies to reconstruct the buried tectonostratigraphic architecture and the articulated pathways for fluid migration, highlighting that once fluids move toward the surface, they follow the main fault zones. Furthermore, their migration and leakage are controlled mainly by the surficial segmentation of faults and local permeability paths. The procedures applied in this study can be helpful for investigations in other natural degassing areas or the CO2 storage industry to investigate the seeping and leakage processes and mitigate the gas migration.

In active calderas, deformation structures associated with collapse are seldom exposed at the surface. One of the deadliest landslides on the island of Ischia (southern Italy), which occurred in 2022 at Mt. Epomeo, exceptionally exposed these structures. This work presents a field study of a ring fault zone associated with caldera collapse during the Mt. Epomeo Green Tuff eruption (MEGT; 62–56.5 ka). The subsequent resurgence of the central part of the caldera furnished the unique opportunity to investigate these rocks and structures. The studied outcrops expose the deepest rocks filling the caldera floor, corresponding to marine deposits (Cava Celario unit, ECV) buried below the MEGT sequence and exhumed during block resurgence. We carried out stratigraphic, structural, and palaeoecological investigations on these deposits, which crop out in the Cava Celario engraving, located along the northern slope of Mt. Epomeo, recently exposed following the dramatic landslide on 26 November 2022. The stratigraphic survey indicates that the ECV unit is composed of two members, separated by a reworked magmatic and pyroclastic debris flow deposit. Lithified varved sediments characterize the lower member (ECV1), whereas the upper member (ECV2) is a massive deposit, both of which are formed by hydrothermally altered, very fine, reworked volcanic rocks. The structural analysis reveals that the ring fault zone is characterized by deformation structures, including folds and faults, the latter defined by both reverse and normal kinematics, suggesting a strain field associated with gravitational collapse, as observed in caldera formation. Finally, studying the fossil content and the inferred paleoenvironment of the ECV unit enabled us to reconstruct the vertical displacement curve of Mt. Epomeo before and during the block resurgence (from 70 ka to the present). The upper member ECV2 terminates with a turbiditic layer containing fossils that indicate an offshore environment and an inferred paleo-bathymetry of 100–200 m b.s.l. The reconstructed vertical displacement indicates first subsidence during the ECV deposition, followed by an uplift (doming) predating the initial rapid subsidence associated with the caldera formation. After that, Mt. Epomeo experienced a general uplift (block resurgence) interspersed with subsidence periods and volcanism along its bounds, accumulating a net uplift of 930 m during the last 56 kyr.

We present the Geological Map of the UNESCO archaeological site of Hattusa in Turkiye. The mapped similar to 5 km2 area is characterized by different superposed thrust sheets of the Upper Jurassic-Cretaceous Ankara Melange succession, which is covered by Quaternary deposits. Here, the Ankara Melange consists of an ophiolitic sequence comprising massive, layered and pillow basalts, gabbros and serpentinites, overlain by a sedimentary oceanic succession including argillites, sandstones, radiolarites, and cherty limestones, and finally capped by channelized calcareous conglomerates. The orogenic architecture is defined by older top-to-the-S thrusts, subsequently deformed by top-to-the-N back-thrusts. High-angle normal, transtensive, transpressive and strike-slip faults crosscut the orogenic pile. The geological map of Hattusa represents an important contribution to the understanding of the unique and complex geological setting that characterizes this region. On the other hand, it is also a crucial piece in the mosaic for assessing the relationship between man and the environment.

Accurate digital elevation models represent the basic tool for a large spectrum of applications, including geological, architectonic, archaeological, and urbanistic studies. However, aggressive urbanization may significantly alter the morphology of areas of interest. Such is the case of the active Campi Flegrei caldera in southern Italy, where all the buildings, facilities, infrastructures, quarries, and landfills altered the original volcanic morphology. To avoid these limitations, we analyzed a set of vintage aerial photographs acquired in 1943 by Italy's Military Geographic Institute (IGM). We reconstructed the study area's topography before the deep anthropic modification from the 1960s onwards by applying Structure-from-Motion photogrammetric processing. On the reconstructed orthomosaic and a historical-Digital Surface Model (hDMS), we conducted geomorphic analyses along 18 longitudinal stream profiles outside, across the border, and inside the caldera, underlining that the rectilinear sections with preferred orientations and increased incision values suggest a strong structural underpinning on valley incision and stream paths. The analysis of the spatial distribution of sinuosity, SL index, Chi (chi) value and knickpoint maps suggests the presence of tectonic lineaments that influence the stream network from the pre-caldera (>40 ka) to recent times, producing articulated caldera and craters geometry as well as affecting the localization of volcanic vents. The comparison between the 1943 hDSM and 2013 LiDAR (Light Detection and Ranging) DSM allowed us to spotlight the areas that show the most significant differences due to anthropic intervention that obliterated critical features, thus supporting our motivation to use this base. Overall, the results indicate that long-lived volcano-tectonic and tectonic structures control the orientation of drainage patterns and their re-arrangements during volcano-tectonic deformation phases. Finally, a comprehensive structural map, based on the merged 1943 hDSM and the bathymetric DEM, is presented together with a conceptual evolutionary model of the stream network across the caldera border. Under the proper acquisition conditions, vintage aerial photographs can provide a useful tool for morphological analysis and can be applied to several topics in the geosciences.

Models of volcanic collapses proposed in the literature rely on combining field examples with analogue and numerical modelling to connect superficial observables to sub-surface volcano-tectonic processes. However, the behaviour of such collapses in an already faulted and fractured medium needs to be better explored.We studied a complex array of normal and reverse faults within the central sector of the active Campi Flegrei caldera, where faults with centimetres-to-meters displacements are hosted in the La Pietra tuff (13.5 ka) and the overlying pyroclastic succession of the last 5.5 kyr. We analyzed the attitude, kinematics and throw of these structures, employing a UAV-based digital outcrop model. The analysis shows that antithetic normal and reverse faults form in the hanging wall of a pre-existing WNW striking, NNE-dipping master normal fault. Moving northward, the strike of the antithetic faults rotates from WNW to NNW directions, with the latter showing a right-lateral oblique component. The simultaneity and coherence of both kinematics and attitudes are verified by the throw analysis. We associated the formation of this array with the caldera-collapse phase of the Agnano-Monte Spina eruption (4.55 ka), which caused off-caldera faulting beyond the main collapsed area.Based on field data, we suggest that during peak caldera-forming phases, wider areas beyond the main caldera scarps can be involved in volcano-tectonic collapses in the presence of a pre-existing fault network and complex tapped reservoirs. This highlights the role of inherited structures in weakening the crust above the magma reservoir that can potentially increase the magnitude and duration of caldera-forming eruptions, as they may induce a broader roof rock subsidence, pressurizing wider regions of the sub-caldera magma system.

Understanding how heterogeneous rock volumes deform is crucial in structural geology, and several studies have addressed this issue by focusing on the impact that the mechanical stratigraphy of a layered stratigraphic sequence has on deformation. However, mechanical layering can also develop subparallel to fault surfaces within the upper crust, and how these anisotropies affect subsequent deformation has been much less explored. This work addresses this aspect by structurally and mechanically characterizing superposed fault zones developed in Triassic dolostones that crop out in the foldand-thrust belt of the southern Apennines. We investigate how layering associated with an early, reservoir-scale, normal fault zone (F1), inherited from Upper Triassic-Lower Jurassic pre-orogenic extension, influenced the deformation mechanisms and the geometry of younger strike-slip faults (F2) that formed at an angle to it in the early Pliocene in association with out-of-sequence tectonics during the Apennine orogeny. We combined field surveys and laboratory analyses using a multiscalar and multimethodological approach. Meso- and microstructural observations and geomechanical, laboratory, and in situ tests were employed to describe fault rock attributes. We found that the architecture of the F1 normal fault primarily consists of four tens-of-meters-thick, subparallel fault rock units. They have a cataclastic core, and are bounded in the hanging wall by cemented micromosaic breccia, and in the footwall by high-strain and low-strain fault rocks. The younger F2 strike-slip faults developed alternatively as either cataclastic shear bands or compaction bands and occur in either local ized or anastomosing geometries. By combining data, we demonstrate that the particle size distribution, porosity, and rock strength of the fault rock units related to older normal faults are the main controls on the deformation mechanisms (i.e., cataclasis versus compaction) and geometry (i.e., localized anastomosed) of the subsequent strike-slip faults. Our study highlights that preexisting highly porous fault rocks favor the development of compaction deformation bands. Conversely, low rock strength facilitates the formation of discrete and diffuse slip surfaces. These results can have significant implications for assessing fluid flow in multifaulted dolomite reservoirs.

In Mycenaean times, the prehistoric settlement of Vivara, an islet of the Procida island close to the Campi Flegrei caldera in southern Italy, was a site of intense trade between peoples travelling the Mediterranean Sea along routes from the Near East and Greece to the coasts of North Africa and Western Europe. The interest in such navigations was linked to the supply of raw metal ore such as copper and tin. The Campi Flegrei area and the Aeolian archipelago already represented some places dedicated to trading these precious products around the middle of the 17th century BC. According to the geologic reconstructions, at that time, the Procida-Vivara area was situated at an altitude of 14 metres higher than nowadays, and the two islands, which are now connected by a bridge about 150 metres long, formed a single body of land. Underwater photogrammetry research conducted in the Gulf of Genito uncovered traces of this harbour system. It revealed a staircase carved into the tuff along the slope at a depth of -1 to -10 metres. The staircase was part of the ancient system of connections between the settlement at the summit of Vivara and the port area. Excavations in Punta D'Alaca have uncovered pottery and other artefacts that support the hypothesis of a dense trade network between the local populations and the Mycenaeans. The site has also yielded evidence of fires and other disastrous natural phenomena, such as mudflows documented by the collapse of huts, that interrupted the flow of historical events. In this context, the present geo-archaeological study carried out in collaboration with the 'Isola di Vivara' State Nature Reserve aims to understand how geological phenomena influenced the evolution of the landscape and, consequently, the social and economic development of the people who inhabited Vivara. We used innovative digitization and analysis methodologies for the emerged and submerged areas of the island to reconstruct the subsidence evolution of the island. The instruments used include drone Lidar, terrestrial laser scanners, photogrammetric systems, thermographic sensors, and structured light scanners. The numerical models, geo-referenced and aligned within a single virtual space, provided information on the geology, botany and archaeology of specific island areas. This information is processed within digital platforms to analyse and visualise the models: the preliminary activities, focused on analytical studies of hydrogeological risk factors of the Vivara system, are conducted within a GIS platform specifically implemented for data management and storage. Then, the 3D models will be used to develop protection and enhancement interventions for Vivara Islet.

In the Taverna San Felice limestone active quarry (Italy) excavation has progressively exposed a magmatic dike embedded in a calcareous succession. The dike outcrops are scattered among the high vertical steps of the quarry, whereas outside the excavated area the steep mountain slope covered by a dense bush vegetation make direct inspection and geological mapping a challenging task. To map the areal extension of the dike and to define its direction and its relationship with tectonic lines over an area larger than the quarry, a magnetic survey was performed. Given the above-mentioned extremely rugged terrain, a UAV-based magnetic survey was the preferred acquisition strategy. Data were acquired by rigidly fixing the magnetometer to the UAV landing sled, using a sensor with a very high-frequency (1000 Hz) acquisition rate. The acquisition strategy and some simple processing steps resulted in a detailed drone-borne total field anomaly map. This dataset allowed for a mapping of the dike outside the quarry area and the identification of a vent fed by the dike. The 2D forward modelling of the magnetic data was constrained by a field estimation of the intensity of the total magnetization and by the depth to the dike's top, in places where it is outcropping.