The succession of the Maiella massif is analyzed, focusing on the colonial-coral bearing deposits occurring just below and immediately above the Cretaceous/Paleogene boundary. The Upper Cretaceous material is dominated by rudists and larger benthic foraminifera with a significant contribution from colonial corals. In the Lower Paleocene, the first two groups are absent and colonial corals dominate the skeletal assemblage. This supports the hypothesis of a good recovery of colonial corals carbonate production following the end Cretaceous extinction and their overall resilience. Similar to modern reefs, Lower Paleocene bioconstructions have a framework dominated by corals and red calcareous algae. However, unlike modern reefs, micrite makes up the vast majority of the internal sediment, suggesting a development into a low-energy environment. Compared to Upper Paleocene coral boundstones, those from the Lower Paleocene of Maiella display a higher abundance of corals, suggesting a reduction in coral carbonate production during the Late Paleocene. This decline is also reflected by a period of scarcity of coral-dominated facies throughout the Tethys, starting from the latest Paleocene and extending till the end of the Middle Eocene. This can be connected to global temperatures, which rise in the Thanetian and remain relatively high till the end of the Middle Eocene, however, other factors most likely played a role. The quantitative analysis of the skeletal assemblage turns out to be a useful instrument for tracking the effect of environmental changes. Further data, especially from long and extensive successions of neritic carbonates such as those of Maiella, may help in disentangling the effects of the other environmental variables.

Summary Petroleum system analogues for underexplored areas are a critical aspect of oil and gas exploration of complex and underexplored geological areas, such as most of the Mediterranean. However, the screening and ranking of surface and subsurface case studies, historical to recent discoveries or published research on similar geological settings is not an undemanding practice, especially for carbonate systems, since the combinations of elements and variables can be countless. In this work, we present the CarbMed GIS (version 2023) a user-friendly GIS-based tool for geological and E&P data synthesis and knowledge management designed to support geological analogue identification and the full range of hydrocarbon exploitation activities, in the Greater Mediterranean area. CarbMed GIS consists of 9 proprietary vectors (layers), linked to a comprehensive geo-database, which provides information on stratigraphy, sedimentology, diagenesis, fluid parameters and petroleum system elements. In underexplored areas, such as the offshore of the island of Crete, CarbMed GIS database, is able to provide insights into the extension of neighboring petroleum systems, by the integration of geological data, regional Gross Depositional Environment Maps and previous discoveries

Summary Mediterranean Mesozoic and lower Cenozoic Carbonate successions host prolific petroleum systems that are the focus of ongoing exploration activity, particularly in Greece and the Levant Basin. These thick carbonate sequences were initiated during the early phases of the development of the Tethys Ocean and range from Triassic to Eocene age. They include sediments deposited within epeiric and isolated carbonate platforms and in deepwater basins. The reservoir and source rock units within many of these petroleum systems are an integral part of the carbonate succession. In contrast, seals are mainly younger clastic sediments or Messinian evaporites overlying the carbonate edifices. However, proven seals do occur within the carbonate sequence and this contribution aims to review their occurrence from the perspective of regional geology. Most intra-carbonate seals are evaporites deposited in sabkha/ lagoonal environments or shelfal carbonate mudstones deposited across shallow marine carbonate domains during drowning events of varying durations. Secondary intra-carbonate seals are fine grained carbonates deposited in either deepwater or intra platform basins. An appreciation of these intra-carbonate seals may serve to unlock deeper hydrocarbon potential and may also be of relevance to energy transition technologies, such as CCS, as these mature and are deployed across the region.

This guide is a 5-day geotraverse across the Central Apennines, which expose the inherited Meso-Cenozoic sedimentary successions and tectonic architecture of the Apennine Tethyan passive margin. This structure was progressively involved into orogenic and post-orogenic tectonics, related to the Tyrrhenian back-arc dynamics. To show the different margin dynamics, we present: 1) sedimentologic and stratigraphic aspects, 2) relations with Neogene compressive and Quaternary extensional structures and 3) a hydrogeological case-study. The trip starts north of Rome, where Quaternary deposits at the transition from marine to continental deposition, including travertines, record the evolution of the Tyrrhenian passive margin. The excursion then moves to the Mesozoic platform margins of the Latium-Abruzzi and Apulia carbonate platforms, where perfectly preserved Cretaceous to Neogene successions occur. The Maiella mountain and Gran Sasso range testify for carbonate production changes, as recorded in facies associations and isotope geochemistry records, related to global climate shifts and regional tectonics. A focus on the hydrogeologic dynamics of the Gran Sasso aquifer is also offered in relation to the current climate change. This guide is the result of a workshop of GeoSed, the Italian Association for Sedimentary Geology, and it also aims at providing a scientific base for geo-touristic explorers.

Summary The Mediterranean is characterized by a wide range of carbonate petroleum systems. In this work, we present a synthesis of these carbonate petroleum systems, based on data contained within CarbMed GIS, a tool for geological and E&P data synthesis and knowledge management that supports the full range of hydrocarbon exploitation activities. The GIS project consists of geological data (e.g. logs, wells, sections, maps, fields) associated with a comprehensive geo-database, which provides information on stratigraphy, sedimentology, diagenesis, fluid parameters and petroleum system elements. In the Greater Mediterranean area, 26 proven petroleum systems that include hydrocarbons reservoired in shallow marine and basinal carbonate reservoirs have been identified and mapped. Within each one of these, a number of carbonate plays have been identified and described based on reservoir characteristics. Results show an asymmetrical framework of petroleum systems and play across the Mediterranean provinces, with the northern area dominated by plays associated with the large and long-lived isolated carbonate platforms of Adria and sourced primarily by deep water and intraplatform basin carbonate source rocks and the southern and eastern areas characterized by plays associated with smaller sized carbonate systems that were deposited on mixed carbonate-clastic shelves.

Summary Carbonate reservoirs in the Greater Mediterranean are associated within a wide range of different platform settings, from mixed evaporite-carbonate epeiric platforms, to isolated platforms and reef systems. In this work we present a new classification scheme based on literature review of 60 commercially exploited carbonate reservoirs. The classification is based on 1) control on poroperm system: diagenetic vs depositional; 2) Gross depositional environment; 3) carbonate factory type. 11 different reservoir types are identified on these bases and their distribution has been mapped out by the location of Mediterranean hydrocarbon fields in which the reservoirs are exploited. The review highlights the limitations of the “reef” paradigm for understanding carbonate reservoirs in the study area and highlights the need for exploitation strategies to be based on depositional models that are appropriate to the “carbonate factory” of interest. The classification scheme and associated database are intended for use during both the exploration phase of a project, and the appraisal/ development stage. It provides a tool to select appropriate depositional and diagenetic models, to understand the range of properties associated with different reservoir types and select analogues.

Summary Isolated carbonate platforms (ICPs) are spectacular features of Mediterranean geology and have long been known to host important hydrocarbon reserves, for example in the Southern Apennines of Italy. Recently there has been a resurgence of interest in the resource potential of Mediterranean isolated carbonate platforms following recent world class exploration successes in this play in the Eastern Mediterranean. The scarcity of subsurface case histories in the Mediterranean Region lets open a series of questions on the characteristics of Mediterranean ICPs and their relationships with the elements of the associated petroleum systems. In order to provide a better understanding of the hydrocarbon potential of this interesting carbonate target, we have developed a regional sequence stratigraphic framework based on a proprietary database, which includes a large amount of public and original data on the carbonate systems of the Mediterranean and on the related petroleum systems. The Mesozoic and Cenozoic Tethyan Megasequences and Petroleum Systems Chart represents the first megasequence stratigraphic framework that attempts to unify Alpine Tethys and Neotethys with North Africa and Eastern Mediterranean, and it provides an exploration and first-order correlation tool for the spatial and temporal distribution of ICPs, and associated petroleum systems across the entire Mediterranean.

Summary In this work we present part of an ongoing research on the geology of the Parnassus Carbonate Platform (PCP) (External Hellenides, Greece), with regards to the mid-Cretaceous stratigraphic interval. The geological features, the outcrops quality and high quality of collected dataset indicate the Parnassus Mt as promising field analogue for the discovered and under-explored Cretaceous reservoirs of the Mediterranean area.

This work describes and analyzes an original collection of fossil corals from the Ellipsactinia Limestones (Kimmeridgian-Tithonian), exposed in the Marsica area (central Apennines, Italy), focusing on taxonomy and paleoecology. 43 species grouped into 32 genera, 16 families and 9 suborders were identified. Astreoidogyra giadae nov. gen. nov. sp. (Rhipidogyridae) and Clausastrea eliasovae nov. sp. (Montlivaltiidae) are new taxa. Corals occur from the back reef to the reef crest, showing a marked zonation, expressed by a variation of coral cover and type, although the reef front and slope facies could not be sampled. The back reef is characterised by scattered medium-to-small colonies, with a relative high variety of colony shape, corallite arrangement types and high taxonomic diversity. Stylosmilia, Calamophylliopsis, Intersmilia, Pleurophyllia, Bracthelia, Heliocoenia, Ogilvinella occur here among others. The inner reef flat records the highest coral cover, with large robust branching, such as “Pseudocoenia”, Heliocoenia, Calamophylliopsis, and large dome-shaped meandroid, such as Psammogyra, Pruvostrastraea, Eugyriopsis) colonies. Within the external reef flat and the reef crest the coral cover is low and the stromatoporoid-bearing mounds dominate on the isolated coral bioconstructions. Controlling factors as bathymetry, hydrodynamic disturbances, abrasive currents, background sedimentation and morphological irregularities of the depositional profile are considered to explain the observed coral zonation. High diversity and low dominance indices are interpreted to result from reef complex heterogeneity, which should have influenced the formation of different ecological niches and consequently the proliferation of a greater number of taxa in a relatively small area.

Isolated carbonate platforms (ICPs) are spectacular features of Mediterranean geology. There has been a resurgence of interest in the resource potential of ICPs in the region following recent exploration success in this play in the eastern Mediterranean. These features have developed in the context of the geologic evolution of the Mediterranean region over the last 250 million years. Their depositional architecture and seismic expression can be very different from that of isolated platforms developed elsewhere and at different times, particularly the Tertiary platforms of Southeast Asia that have formed the basis of much of the industry literature on the seismic characteristics of ICPs. Important differences arise from the fact that Mediterranean ICPs developed on microcontinents in an active tectonic environment featuring both extension and compression, from the range of carbonate factories that have characterized their development, and from the prolonged nature of exposure that they have periodically experienced. These differences can render the application of some criteria documented in the literature for identification of ICPs problematic in a Mediterranean context. While it is difficult to propose universally applicable criteria for identifying Mediterranean ICPs, locating and mapping the position of the platform slope, often relatively easily identified on seismic data except where hidden by subsequent compressional deformation, is probably the most robust criteria.

This work investigates a portion of a poorly documented upper Tithonian reef (Lower Mt. Bardia Reef, LBR) developed along the northern platform margin of the eastern Sardinia Platform (ESP). The LBR was probably one of the most southerly reefs of the northern Tethys margin, and this study provides the first comprehensive description of facies and internal structure, giving insights for the depositional setting. Detailed compositional and fades analyses of LBR have been carried out in three quarries located in the Orosei Gulf (eastern Sardinia). The main reef components are represented by carbonate (bioclastic) debris, microbialites and microencrusters, and reef-building organisms (mainly corals and stromatoporoids). These components combine in various proportions, forming several facies and facies associations. Ten reef facies (RF), grouped into three main Facies Associations have been identified within the studied reef portion. The distribution and arrangement of facies reveal a sedimentary evolution, evolving from a microframework-dominated reef to a carbonate debris-dominated one, with the internal reef architecture evolving from massive, to patchy, to coarsely stratified and roughly bedded. The reef components and facies indicate that the investigated portion of the LBR corresponds to a shallow back-reef zone, characterized by well-lit and generally low-energy hydrodynamic conditions, possibly developed in back position with respect to a higher-energy zone that was closer to the edge of the platform. In this depositional context, the arrival of large amounts of debris and the evolving internal architecture are interpreted as the result of the infilling process of the back-reef zone due to the progradation of a sand apron, during a long-term regional regressive phase. (C) 2018 Elsevier B.V. All rights reserved.

This study shows the importance of incorporating outcrop analogs in the analysis of subsurface reservoirs. Within this context, the detailed study of outcropping surface analogues combined with the Geologic model building and validation of the geological sections, brings fundamental constraints in performing reservoir modelling, thus providing more realistic predictive models. Forward seismic modelings allow us to test the relationship between geology and seismic response, and are potentially very well suited to improve the geological interpretation of seismic data. Seismic models of outcrops can contribute effectively to the interpretation of seismic data. In fact, they are essential for qualifying petroleum targets, because they bridge a critical gap in both resolution and scale between architectural geometries observed in outcrops and in seismic data.

Summary Three-dimensional (3D) geological models of outcropping analogues provide helpful tools to better understand complex geological subsurface structures and reservoir geometries. In this study, a 3D geological modelling of an outcropping slope-to-basin carbonate system has been presented taking into account the case of the Maiella Mountain in the Central Apennines of Italy, which represent an excellent analogue for hydrocarbon plays located along the transitional zone of the Apulian platform in the Adriatic offshore. The 3D modelling and visualisation performed in this study helps to understand the geometrical characteristics, extension and lateral distribution of the paleoescarpment and megabreccia bodies which represent one of the main target reservoir along the Apulian margin in the central Adriatic offshore.

The brightest geoscience students competed for the best student submission to the EAGE Annual Meeting 2015. Competition was fierce, but after much deliberation three papers have been chosen to be presented as part of the EAGE Technical Programme in Madrid.

Summary A good geological and petrophysical description of reservoir complexity (heterogeneity) forms the basis for optimum field development and maximising hydrocarbon recovery. However, severe limitations are often imposed by relatively low seismic resolution, especially for deeply buried reservoirs, and by wide well spacing. These limitations can be partly overcome by studying reservoir analogues, similar ancient sedimentary rocks which crop out on the Earth's surface. The proposed case study offers a great opportunity for analyzing the characteristics of resedimented-derived carbonate deposits, which represent an excellent outcrop analogue for potential carbonate reservoirs in the central Adriatic offshore.

This study provides the first quantitative carbonate production estimate of an ancient debris reef, represented by the Upper Jurassic reef complex of the central Apennines. The components of carbonate production (Pnet, Psed, and Pgross) have been defined entirely on the basis of outcrop data. The reef volume (Pnet) was reconstructed based on the present distribution of the Upper Jurassic reef complex and its relationship with coeval successions of platform and slope. The volume of sediment exported along the slope (Psed) was obtained through the reconstruction of the thickness reduction pattern of the reef-derived sediments, at increasing distances from the platform margin. Several variables have been introduced to overcome the lack of data in some areas.The estimates obtained indicate that the Upper Jurassic reef complex produced a total amount of calcium carbonate equal to 1.7-2.3 times the amount of material retained in the reef complex. This excess volume of sediment produced was redistributed along the slope-basin system, up to a distance of similar to 55 km from the platform margin. According to the indices commonly used for quantifying carbonate production, the Upper Jurassic reef shows values that are consistently lower than other ancient and Holocene reef systems. The interaction between the sedimentologic characteristics of the reef structure and the hydrodynamic processes is ultimately seen as the main mechanism responsible for the low growth potential and reduced export of reef material. The methodology and the procedure used were designed specifically for the site being studied but could potentially be adapted for use in other regions where the data required are difficult to access.