Abstract Hydrocarbon distribution in the Southern Apennines thrust belt of Italy is directly related to the geological characteristics and complex evolution of the thrust tectonic pile involving units from different palaeogeographical domains. Within this structural–stratigraphic context, the main exploration target is represented by the carbonate units of the Apulian Platform, which contain the largest and deepest oilfields in the region. By integrating different types (e.g. wells, seismic, maps, reports) of legacy public and confidential data of various vintages, the subsurface structural setting of the contractional Apulian structures around the Benevento Field in the Southern Apennines hydrocarbon province is reconstructed. The discovery dates back to the early 1970s. The reservoir consists of Cretaceous–Lower Miocene carbonates at a depth of around 3000 m below sea level bearing both oil and gas. A new digital interpretation and integration, which takes into account the most recent understanding of the evolution of this thrust belt, has allowed reconstruction of the trap style of the Benevento Field and of the prospective (undrilled) structures in the surrounding area. A history of positive inversion tectonics is interpreted from a 2D kinematic restoration; this has important implications for both the structural style and the hydrocarbon prospectivity of the Southern Apennines thrust belt.

Abstract The superposition of structures produced by different tectonic phases is common in sedimentary basins. Yet the earlier structures often remain overlooked with potentially negative exploration consequences. In the Maiella anticline, Pliocene compression has folded carbonate sequences containing Cretaceous extensional structures. The geometry and evolution of the Apulian carbonate platform margin outcropping on the Maiella Mountain are described by two opposing groups of models. One proposes a structurally controlled platform margins cut by syn-sedimentary Cretaceous faults; the other assumes a passive Cretaceous palaeo-escarpments progressively filled by Cretaceous to Tertiary sediments later deformed by the Pliocene compression. Assuming models in line with either one of these two groups has significant implications for exploration plays on both platforms and adjacent basins of analogous subsurface systems. These include: hypothesized margin geometries; sediment transport mechanisms (directions and distribution); size of sequences; type and size of traps and associated exploration targets, risks and uncertainties. We demonstrate that during the Late Cretaceous the platform margin was cut by normal faults which controlled the palaeogeography of the platform and the sediment input into the adjacent basin in which thick, resedimented, carbonate megabreccia and turbidites were deposited. These carbonates represent exploration targets in similar settings worldwide.

Abstract Small-size karst landforms may potentially provide very useful information to fully understand the behaviour of karst systems and their dynamics. In this chapter we demonstrate the need to pay attention to such features. ‘Inghiottitoio della Masseria Rotolo’, located in a remarkable karst area of southern Italy, has in recent years become the most controversial and discussed speleological site in Apulia. Even though it has been known for several decades, recently excavation work has allowed cavers to enter a huge karst system, eventually reaching the water table. The total depth of the cave is now 324 m, making it the deepest in the region. This chapter summarizes the history of discoveries at the site, starting from the description of the polje, also including information about the link between toponymy and karst. The works carried out at the swallet site are then described to emphasize the importance of the often neglected small-size karst features. In fact, when carefully observed and studied, these might be able to shed new light and greatly increase our knowledge about karst. The final part of the chapter deals with the cave system and provides an outline of the ongoing research.

Abstract Sinkholes are the main hazard related to underground voids of both natural and anthropogenic origin. Instabilities developing underground may propagate upwards in a dramatic manner and reach the surface in the form of a sinkhole. The Apulia region in southern Italy is an interesting case study due to the outcropping of soluble rocks throughout the region. These rocks are affected by karst processes and have a high number of anthropogenic cavities. The latter were excavated by humans at different times for a variety of purposes. The worrying recent increase in the number of sinkhole events registered in Apulia led us to collect information on natural and anthropogenic sinkholes in Apulia. We focused on anthropogenic cavities, mostly excavated in Plio-Pleistocene calcarenites, and characterized the rock masses before using two- and three-dimensional parametric numerical analyses to model the instability processes, with the aim of exploring the failure mechanisms that lead to the occurrence of sinkholes. The parametric studies allowed us to carry out a preliminary evaluation of the stability conditions through simple charts designed for use in the field.

Abstract: The study of natural analogues can inform the long-term performance security of engineered CO 2 storage. There are natural CO 2 reservoirs and CO 2 seeps in Italy. Here, we study nine reservoirs and establish which are sealed or are leaking CO 2 to surface. Their characteristics are compared to elucidate which conditions control CO 2 leakage. All of the case studies would fail current CO 2 storage site selection criteria, although only two leak CO 2 to surface. The factors found to systematically affect seal performance are overburden geopressure and proximity to modern extensional faults. Amongst our case studies, the sealing reservoirs show elevated overburden geopressure whereas the leaking reservoirs do not. Since the leaking reservoirs are located within <10 km of modern extensional faults, pressure equilibration within the overburden may be facilitated by enhanced crustal permeability related to faulting. Modelling of the properties that could enable the observed CO 2 leakage rates finds that high-permeability pathways (such as transmissive faults or fractures) become increasingly necessary to sustain leak rates as CO 2 density decreases during ascent to surface, regardless of the leakage mechanism into the overburden. This work illustrates the value of characterizing the overburden geology during CO 2 storage site selection to inform screening criterion, risk assessment and monitoring strategy. Correction notice: The original version was incorrect. This was due to an error in the Acknowledgements and Funding section, which omitted to list the funding bodies of RSH.