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This work focuses on the carbonate factories constituting the Pietra di Finale Fm cropping out in the Ligurian Alps. This unit constituted a mixed carbonate–siliciclastic coastal wedge developed during the Middle Miocene. The carbonate factories characterizing the coastal wedge of the Pietra di Finale clearly differ from those of the coastal mixed systems and carbonate platforms developing during the Miocene elsewhere in the Mediterranean area. Here, in the Ligurian Alps, the euphotic carbonate factory does not show any evidence of seagrass meadows and coral bioconstructions. Zooxanthellate corals are present only as skeletal debris associated with abundant stylasterids. In the mesophotic and oligophotic zones, the typical oligophotic biota of red algae and larger benthic foraminifers are strongly reduced. The coastal wedge of the Pietra di Finale shows an unusual abundance of stylasterids, classically interpreted as deep-water biota. However, in this example, the absence of low-energy textures and other skeletal components suggest a shallow-water origin, probably in the eu- or mesophotic zone. The stylasterids colonized the hard substrates available and were successively removed and resedimented to form the skeletal fraction of the coastal wedge of the Pietra di Finale. The abundance of stylasterids is restricted to particular and limited situations in the Miocene of the Mediterranean, thus suggesting that their abnormal development is controlled by local rather than global factors.

Despite data coming from fully developed oil fields are fundamental to validate reservoir models, they are rarely publishable because of confidentiality. In this work, we benefit from an exceptionally dense public dataset represented by 43 wells logs drilled in a carbonate-heavy oil-rich reservoir of the Majella Mountain (Central Italy) over a grid of 200 m × 200 m, with depths in the range of 90–200 m. We tested different modelling solutions, to assess the best modelling approach that fits the available data on hydrocarbon distribution. Both deterministic (using Kriging) and stochastic simulations (using Sequential Gaussian Simulation- SGS) were tested. The role of the variogram resulted as a fundamental parameter for both simulation methods. Wells-derived variogram agrees with the size and orientation of carbonate dunes that drive the hydrocarbon distribution highlighting the importance of an accurate depositional model. Kriging was faster in terms of computation time and better in maintaining the lateral continuity of the layers, however, it excessively smoothed the results. SGS gave a better distribution of computed values but the lateral continuity was not preserved. By adding a main vertical trend derived from the upscaled logs to the SGS, results become more accurate. We then applied the best model to estimate the total volume of hydrocarbon in place in an already exploited area starting from just one well. The computed reserves show a good fit with historical production data demonstrating the reliability of the model.

The Eocene-Oligocene transition represents the latest greenhouse-icehouse shift faced by Earth, a major global climate change associated with carbon cycle perturbation. In this paper, we investigate the Massignano strati- graphic section (northern Apennines, Italy), GSSP of the Eocene-Oligocene boundary, by X-ray diffraction analy- sis of clay minerals and carbon and oxygen stable isotopes to explore the link among climate, paleoweathering and runoff, and carbon cycle in the Neotethys across this major climatic transition. We examine the interplay be- tween global climate forcing and orogen evolution controlling the Massignano hemipelagic sedimentation. The late Eocene clay mineral assemblages indicate that the Neotethys was sensitive to global eustatic changes as well as changes in composition and rates of weathered sediments accumulating into the basin. The carbon iso- tope record matches with the global signal, showing productivity pulses linked to cooling phases and sea-level drops before 34.8 Ma. Subsequently, a constant negative trend is recorded, which is consistent with the global carbon isotope curve, and attests for a decrease of primary productivity linked to decreasing atmospheric CO2. This negative trend ends at the Eocene-Oligocene boundary, when the onset of the global carbon isotope positive excursion is recorded also within the Massignano hemipelagic succession. On the contrary, the clay mineral as- semblage is quite constant across the Eocene-Oligocene boundary reflecting the complex interplay among fluvial discharge, sea level changes and orogen dynamics which clouded the global climate shift. In this context, the en- hanced fluvial discharge likely contributed to sustain high trophic conditions in the Adriatic waters and, in turn, the Oligocene positive carbon isotope shift. These results highlight how clay minerals proved to be a useful proxy to identify the interplay between global and regional controlling factors on hemipelagic sedimentation and, their integration with the carbon isotope record, provides insights into carbon cycle dynamics.

This work illustrates a combined modelling approach using digital photogrammetry and geological modelling to create a high detailed 3D facies model of the inner environment of the Monte Carrubba carbonate ramp outcropping in the South Sicily. The Monte Carrubba Formation (Tortonian-lower Messinian) is the youngest marine Miocene carbonate deposit of the Hyblean region, prior to the Messinian crisis of the Mediterranean. In particular, Faro Santa Croce outcrop, which is in vertical thickness up to 8 m shows the most proximal sector of this ramp. The Faro Santa Croce outcrop offers the opportunity to investigate and reproduce a highly-detailed facies heterogeneity 3D model for a very narrow and limited area of few squared kilometers (0.1 Km2), developed in a tectonically stable area. Within this small areal, five facies have been recognized and modelled revealing a high level of facies heterogeneity. In this area marine ooidal shoals (ooidal grainstone to packstone) interfingered with shallow water seagrass environment (green-algal-floatstone facies and bioclastic grainstone-to-packstone facies) with abundant mollusc fauna. The distal part of this vegetated environment (fine-grained mollusc-packstone facies) passed basinward into coral mounds (coral boundstone). The combination of digital photogrammetry and 3D geological modelling software has allowed to obtain a very high-resolution model of facies heterogeneity, evidencing the complexity of facies associations and, in particular, the development of a facies mosaic that can be underestimated by a classical 1D or 2D field analysis, especially in limitedly exposed outcrops.

The aim of this work is to reproduce a metre-scale facies heterogeneity 3D model of the Chattian Porto Badisco Calcarenite carbonate ramp outcropping in the Salento Peninsula (southern Italy). However, in shallow-water carbonate systems, capturing metre-scale facies heterogeneity in three-dimensional models remains controversial due to the possibility of facies coexistence and because their association can change through time and space. Within this context, the continuous and well-exposed Chattian Porto Badisco Calcarenite carbonate ramp allows detailed study of the distribution of lithofacies association and their architecture along the dip direction depositional profile. The lithofacies and the depositional model of the Porto Badisco Calcarenite are referred to those defined by Pomar et al. (2014). The Porto Badisco Calcarenite is a homoclinal carbonate ramp with a euphotic inner setting characterised by the extensive seagrass meadows, passing basinward into a large rotaliid packstone and coral mounds developed in mesophotic conditions. The deeper part of the oligophotic zone is characterised by rhodolithic floatstone to rudstone and large lepidocyclinid packstone. The distal part of the ramp is characterise by a fine calcarenite. The methodology used in this work combines classical field data collection (e.g., stratigraphic logs and field-facies mapping) and 3D stochastic modeling by using Petrel™. All the data (top and base of stratigraphic logs, cross-section, key surfaces, lithofacies lateral extension etc.) were georeferenced and inserted into the software to build the digital outcrop model. The 3D facies model has been performed after several simulations through specific stochastic algorithms (SISim, TGSim), comparing the models reproduce by the two algorithms, matching the depositional geometries and the lithofacies association observed in the outcrop. The 3D modeling represents a useful tool to better understand the facies architecture and their complex heterogeneity. Moreover, a detailed 3D facies model provides an essential tool to characterise semi-quantitatively sedimentological features for subsurface reservoir studies.

The 87Sr/86Sr isotope ratio has been widely used as a physical tool to date and correlate carbonate successions due to the long Sr residence time in comparison with the ocean mixing time. If this method works on oceanic successions, marginal basins may show different Sr isotope records in comparison with the coeval ocean one due to sea-level variations, continental run-off and restricted water exchanges. In this work, we present the 87Sr/86Sr isotope record of the upper Miocene carbonate ramp of the Lithothamnion Limestone (Majella Mountain, central Apennines), as an example of the onset of restricted water exchanges between a marginal basin and the ocean water masses. The overall latemost Tortonian-early Messinian Sr isotope record of the Lithothamnion Limestone fits below the global reference line. This deviation has been interpreted as due to the strong control that freshwater input and enhanced continental run-off, linked to the migration of the Apennine accretionary wedge and foredeep system, have had on the central Adriatic water chemistry. These results imply that an accurate oceanographic and geodynamic framework along with diagenetic overprint investigation has to be taken into consideration prior to apply SIS on carbonate successions on marginal basins, even when facies analyses indicate fully marine conditions. This seems to be the case for the upper Miocene Central Mediterranean carbonate successions, but may have more general validity and be extended to other recent or past marginal basins.

The Eocene-Oligocene Transition is a key interval in the evolution of the modern climate, representing the last greenhouse-icehouse transition faced by the Earth. Shallow-water carbonate systems hold essential information of the global changes related to the E-O Transition. In this work, we focus on the Majella Mountain carbonate ramp to identify the shallow-water sedimentary expression of the oceanographic and sea-level changes related to the E-O Transition, and to compare it with the deep-marine records and the coeval shallow-water successions. Field observations, coupled with the study of thin sections to identify textural characters, and of the larger benthic foraminiferal associations for biostratigraphic purposes, allowed reconstructing the depositional model and the stratigraphic distribution of the examined ramp. The lower Rupelian ramp outcropping in the Majella Mountain is characterized by seagrass meadows in the euphotic inner ramp. Corals developed in the middle ramp, building mounded cluster reefs in the mesophotic zone, below wave base, in high hydrodynamic conditions produced by rip-currents induced by storm events or by the breaker zone of internal-waves. The outer ramp consists of alternating bioturbated wackestone rich in planktonic foraminifera, bioclastic packstone and skeletal rudstone to floatstone. The depositional model of the Oligocene ramps is the result of the major changes that occurred during the greenhouse-icehouse transition. In the Majella platform, the E-O Transition corresponds to an unconformity developed on the Priabonian substrate, where the cluster reefs grew and expanded. The unconformity results from the sea level drop of tens of meters, recorded also in the outer ramp, related to the Oi-1 event. The cluster reefs started to develop when the Priabonian ramp was flooded and continued to grow during the following highstands, forming an extensive coral unit that prograded basinwards, interfingering with the outer ramp deposits.

Two stratigraphic sections located in the Latium-Abruzzi (Monte Porchio, Central Apennines, Central Italy) and in the Apulian carbonate platform (S. Cesarea-Torre Tiggiano, Salento, Southern Italy) were measured and sampled to document the sedimentological characteristic and the faunistic assemblages of Middle Eocene seagrass deposits. The faunistic assemblages are dominated by porcellaneous foraminifera Orbitolites , Alveolina, Idalina , Spiroloculina , Quinqueloculina , Triloculina and abundant hooked-shaped gypsinids, associated with hooked red algae and green algae Halimeda . Fabiania , rotaliids and textulariids as well as nummulitids are subordinated. The samples were assigned to Lutetian (SBZ13–16) according to the occurrence of Nummulites cf. lehneri , Alveolina ex. gr. elliptica , Idalina berthelini , Orbitolites complanatus , Slovenites decastroi and Medocia blayensis . At Santa Cesarea reticulate nummulites occur in association with Alveolina spp. and Halkyardia minima marking the lower Bartonian (SBZ17). Three main facies associations have been recognised: I) larger porcellaneous foraminiferal grainstones with orbitolitids and alveolinids deposited into high-energy shallow-water settings influenced by wave processes that reworked the sediments associated with a seagrass; II) grainstone to packstone with small porcellaneous foraminifera and abundant permanently-attached gypsinids deposited in a more protected (e.g., small embayment) in situ vegetated environment; III) bioclastic packstone with parautochthonous material reworked from the seagrass by rip currents and accumulated into rip channels in a slightly deeper environment. The biotic assemblages suggest that the depositional environment is consistent with tropical to subtropical vegetated environments within oligotrophic conditions.

The stratigraphic architecture of the Bolognano Formation documents the evolution of the Majella carbonate platform in response to global and local changes that affected the Mediterranean area during the Oligocene–Miocene interval. The Bolognano Formation consists of a homoclinal ramp that developed in a warm, subtropical environment. Five different lithofacies associations have been identified: Lepidocyclina calcarenites, cherty marly limestones, bryozon calcarenites, hemipelagic marls and marly limestones, and Lithothamnion limestones. Each association corresponds to a single lithostratigraphic unit except for the Lepidocyclina calcarenites that form two distinct lithostratigraphic units ( Lepidocyclina calcarenites 1 and 2). These six units reflect alternation of shallow-water carbonate production and drowning. Specifically, two of the three stages of shallow-water carbonate production regard the development of wide dune fields within the middle ramp, one stage dominated by red algae and a sea-grass carbonate factory, whereas the two drowning phases are represented by marly cherty limestones and calcareous marls. A new biostratigraphic framework for Bolognano Formation is presented, based on high-resolution analysis of calcareous nannofossil assemblages, which proved to be very useful for biostratigraphic constraints also in shallow-water settings. Using this approach, we have linked the first drowning phase, late Chattian–Aquitanian p.p. in age, to western Mediterranean volcanism and the Mi-1 event, and the second drowning phase, late Burdigalian–Serravallian in age, to the closure of the Indo-Pacific passage and the occurrence of the global Monterey event. These results permit a new deciphering, in terms of sequence stratigraphy, of the Bolognano Formation that is interpreted as a 2nd-order super-sequence that can be subdivided into 3 transgressive–regressive sequences.

The Middle to Late Miocene mixed carbonate-siliciclastic coastal wedge of the Pietra di Finale, unconformably overlying the Ligurian Alps succession, displays a carbonate portion dominated by Halimeda and Porites fragments that fall in the photozoan assemblages. Photozoan assemblages typically develop under tropical and oligotrophic conditions, while hetorozoan assemblages tend to thrive in high-nutrient settings. The Pietra di Finale Formation shows, however, that high weathering and an increase of nutrient inputs related to Alpine uplift and humid climatic conditions promoted Halimeda over the seagrass carbonate factory in the photic zone. The successful Halimeda proliferation was due to its efficient competition for nutrients, especially nitrogen. Thus, the Pietra di Finale Formation represents an interesting, counter-intuitive example in which increased nutrient concentrations promoted, instead of inhibited, a photozoan over a seagrass-related heterozoan carbonate production.

Summary Central Italy, eastern onshore and adjoining Adriatic Sea off-shore, along the front of the Appenninic chain foredeep, is characterised by know evidences of an active petroleum system, proven by subsurface discoveries, outcropping heavy-oil fields and even a natural “oil spring”, reported since antiquity. In this work we present the dataset we have been re-constructing in 3D at different scale, and discuss the main elements of this active petroleum system from Source-Rock intervals, to the key Reservoir/Seal intervals, investigated by wells and partially outcropping along the NW flank of the Maiella Mountain.

Sedimentary facies of seven Posidonia oceanica meadows of western Mediterranean Sea were investigated. Five meadows are located in the Tyrrhenian coast, two are placed in the western coast of Sardinia and Corsica. These meadows develop on soft and hard substrates, often forming "mattes", in areas characterized by different oceanography, morphology, and terrigenous inputs produced by coastal erosion and fluvial runoff. A total of five sedimentary facies have been recognized ranging from pure terrigenous to bioclastic: terrigenous sand to gravelly sand, bioclastic sands, skeletal gravelly sands, mixed siliciclastic-carbonate sands, well to moderately sorted skeletal siliciclastic sands. All of the sedimentary facies associated with P. oceanica are in the sand grain size. The gravelly fraction is generally subordinated and variable, whereas the muddy fraction is generally low. The very low frequencies of the muddy fraction can be attributed to re-suspension processes and to the lack of carbonate mud production. The rate of epiphytic carbonate production obtained by two of the investigated meadows averages 400 g m(-2) year(-1). This value is in the range of temperate Mediterranean as well as of tropical and subtropical seagrasses. The epiphytic carbonate production plus the calcareous biota living on seagrass substrate contributes to form mixed siliciclastic-carbonate sediments of the nearshore environment of the Mediterranean. Lastly, the carbonate production associated with seagrass was derived by biota belonging to the heterozoan assemblage, where aphotic organisms are dominant, together with oligophotic biota such as coralline algae and symbiont-bearing foraminifera. Consequently, in the well-illuminated seagrass settings, the prevalent skeletal assemblages is represented by the heterozoan association while the components of the photozoan assemblages are absent or subordinate. This a key point for the paleoenvironmental reconstruction of the photic zone in the fossil record. Because the skeletal components of many seagrass dwellers greatly contribute to the carbonate sediment production of photic shallow-water environments, the seagrass meadows became substantial places of carbonate production and C (organic and inorganic) sequestration during the Cenozoic.

A mixed carbonate–siliciclastic succession developed on the southern margin of the Bonifacio Basin (Cala di Labra, SE Corsica) during the Burdigalian, in the margin of a back-arc setting which had formed during the Sardinia-Corsica block rotation. This shallow marine setting was fed by abundant nearshore siliciclastic supply, and substantial carbonate production/accumulation increased from the euphotic to the oligophotic zones. Two third-order depositional sequences (SD1, SD2) corresponding to Bur 3 and Bur4, are recorded in the sedimentary succession.

Many sedimentary processes can lead to the formation of mixed carbonate–siliciclastic sediments in shallow shelf environments. The Miocene Saint-Florent Basin (Corsica), and in particular the Monte S. Angelo Formation, offers the possibility to analyze coarse mixed sediments produced by erosion of a rocky coast, ephemeral stream input, and shallow-water carbonate production dominated by red algae. The Monte S. Angelo Formation was deposited during the Burdigalian to Langhian interval. During this interval, the island of Corsica experienced increased subsidence related to the development of the Ligurian-Provencal Basin and associated Sardinia-Corsica block rotation. Four main rhodolith-rich subfacies have been recognized: conglomerate with rhodoliths, massive rhodolith rudstone, well-bedded rhodolith rudstone, and rhodolith floatstone. The four facies have been interpreted as having been deposited in different environments of a gravel-dominated, nearshore to offshore prograding wedge. Deep-water melobesioids dominate the red algal assemblage from shoreface to offshore. Shallow-water subfamilies of lithophylloids and mastophoroids occur in only accessory amounts. Poor illumination is believed to be due to terrigenous input by ephemeral streams and wave- and current-resuspension. Resuspension processes are favored by the limited occurrence of seagrasses. Two types of siliciclastic–carbonate mixing processes characterize the investigated rhodolith-rich deposits: (1) punctuated mixing, produced by the re-deposition of terrigenous sediments by debris-flow processes during flooding events onto carbonate sediments together with rhodoliths of the shoreface environments, and (2) in situ mixing, produced by growth of coralline algae on siliciclastic pebbles to form the rhodoliths.

The middle Miocene is an important time to understand modern global climate evolution and its consequences on marine systems. The Mid-Miocene Climatic Optimum (between 17·0Ma and 13·5Ma) was the warmest time interval of the past 35 million years during which atmospheric CO2concentrations were lower than today. In the Mid-Miocene Climatic Optimum, a significant carbon cycle perturbation occurred, expressed as a last long-term positive carbon isotope shift, known in literature as the Monterey Carbon Isotope Excursion and recorded in open-ocean settings. In this work, the lower to middle Miocene carbon isotope records from three different domains of the Central Mediterranean are analysed with the aim of identifying the local carbonate platform response to the major global carbon cycle perturbation of the Monterey Event. Carbon and oxygen isotope ratios have been measured on samples belonging to three different stratigraphic sections, two of them are representative of shallow-water settings (Latium–Abruzzi and Apula platforms), and the latter of a hemipelagic setting (Umbria–Marche Basin). A well-defined Monterey Carbon Isotope Excursion is recorded also in these shallow-water sections. Despite their expected problematic stratigraphic constraints, a reliable age model is provided by calcareous nannofossil biostratigraphy and strontium isotope stratigraphy. In both of the carbonate platform successions examined, the Monterey Carbon Isotope Excursion coincides with a spread of bryozoans over other carbonate-producing biota. The high productivity of the bryozoan-dominated factory in the aphotic zone had an important control on the platform depositional profile. The high rates of sediment production in the deeper aphotic and oligophotic zones produced a depositional profile of a low-angle ramp.

This is the final paper of:Sedimentology and depositional architecture of tidal compound dunes on a carbonate ramp: The lower Miocene deposits of the central Apennine (Latium, Italy). - Author:Salvatore Milli,Sergio Madonna,Marco Brandano,Laura Corda - Publication:Marine and Petroleum Geology -Publisher:Elsevier Date:December 2016 -© 2016 Elsevier Ltd. All rights reserved. https://doi.org/10.1016/j.marpetgeo.2016.10.020 Abstract The sedimentology and sequence stratigraphy of the central Apennine lower Miocene carbonate deposits (Guadagnolo Formation) are the goal of this paper. The Guadagnolo carbonate ramp deposits consist of a thick succession of three main lithofacies: marls, marly limestones and cross-bedded limestones. The lateral and vertical facies distribution, as well as the biota assemblages, suggests a deposition of these sediments along the middle-outer ramp sector of the Latium-Abruzzi carbonate platform. All the data suggest sedimentation under the influence of tidal currents that were responsible of bedforms generation as simple and compound dunes. These bodies are developed on metric and decametric scale, and are stacked one to other to form complex sedimentary bodies extending both in strike and dip section for several tens to hundred meters. The dune system developed in a semiclosed basin (the Paleoadriatic sea), open in the southern and closed in the northern sector respectively. Within this basin a probably amphidromic system developed. The flow sediment transport was dominantly westward, and was conditioned by the ramp paleotopography. From a sequence stratigraphic point of view several high and low rank depositional sequences that were differentiated basing on their relative physical scale (thickness of each unit) and on the lateral extension of the unconformities and the correlative conformities bounding them were recognized. The hierarchy of recognized sequence-stratigraphic units include, from the smallest to the largest: simple depositional sequences, low-rank composite depositional sequences and high-rank composite depositional sequences. In the Guadagnolo succession four high-rank composite depositional sequences having a duration variable from 0.9 to 1.6 Ma, and named Guadagnolo 1, 2, 3, and 4, were recognized. These high-rank composite sequences are internally constituted by a stacking of simple and low-rank composite depositional sequences, having a duration ranging from 40 ka to 200 ka. All these units constitute part of a higher-rank composite sequence developing between 21 and 14.80 Ma that we name “The Guadagnolo Depositional Sequence”. The wedge-shaped geometry, the thickness variation and the stacking pattern of the Guadagnolo succession are the response to eustasy and tectonic subsidence. The glacial eustasy mostly controlled the formation of the high-frequency depositional sequences, tectonic subsidence, related to the roll-back of the hinge west-directed subduction in turn connected to the advancement of the Apennine thrust modulated the accommodation space.

Coral bioconstructions associated with mixed carbonate-siliciclastic settings are known to be strongly controlled by coastal morphology and paleotopography. A striking example is represented by the different types of coral bioconstructions and coral-rich deposits of the Cala di Labra Formation deposited in the coastal environment of the Bonifacio Basin (Corsica, France) during the Early Miocene. Detailed mapping on photomosaics allowed accurate documentation of the internal organization of coral deposits as well as lateral and vertical facies relationships. Four types of coral bioconstructions (CB) and one reworked coral deposits (RCD) have been recognized. The CB are represented by sigmoidal cluster reefs, coral carpets and skeletal conglomerates rich in corals. The RCD occurs in lens-shaped bodies intercalated within clinoforms composed of bioclastic floatstones and coarse packstones. The investigated bioconstructions can be contextualised in a coastal environment. In the upper shoreface corals developed in association with the oyster Hyotissa, above bioclastic conglomerates sourced by ephemeral streams and erosion of the granitic coastline. In the lower shoreface corals formed sigmoidal bioconstructions interpreted as cluster reefs, whereas coral carpets developed during a relative sea-level rise related to the middle Burdigalian transgressive phase. The reworked coral deposits can be interpreted as lobe-shaped deposits of coarse-grained bioclastic submarine fans formed at the base of the depositional slope of an infralittoral prograding wedge system., Rivista Italiana di Paleontologia e Stratigrafia (Research In Paleontology and Stratigraphy), Vol 122, No 1: In progress

The Tortonian sedimentary succession of Menorca Island (Balears, Spain) includes two stratigraphic sequences: the lower Tortonian distally-steepened carbonate ramp and the coral reef complex of late Tortonian-early Messinian age. The boundary between the two sequences corresponds to Heterostegina -rich sediments in the western part of Menorca, and to a phosphatic hardground in the eastern part of the island. In the field, the hardground is represented by a dark-brown layer and a rough surface on top of the Tortonian Ramp deposits. Dark phosphate precipitates infill cracks and borings in the underlying limestone to a depth of up to 50 cm. The phosphatic hardground is overlain by planktonic rich wackestone to packstone, which penetrates downward into the fissures, borings, and vugs. This deposit is characterized also by grains of reworked phosphate, glauconite grains, small benthic foraminifers and is followed by tabular beds of bioclastic packstone to wackestone with abundant thin crusts of coralline algae. Based on the Amphistegina tests shapes and red algal assemblage of sediments below and above the hardground, and the lateral correlation with Heterostegina deposits, the bathymetry for the development of the phosphatization is estimated less than 100 m. The limited localization of the phosphatic hardground at the eastern side of the ramp indicates that a dynamic upwelling of deeper and nutrient-enriched waters favored development of a phosphatic hardground. This upwelling episode is representative of the paleoceanographic settings induced by the climate conditions of the Mediterranean area during the Tortonian.

This work illustrates the evolution the Lower Jurassic shallow-water carbonates known as the Calcare Massiccio Formation in the Central Apennines (Italy). The Calcare Massiccio is characterized by lateral and vertical variability in the facies associations, related to an articulated physiography of the Triassic to Lower Jurassic carbonate platform and to its tectonic evolution. This work documents the depositional environment changes during the platform evolution. Quantitative analysis on samples collected from three stratigraphic sections were performed through the Calcare Massiccio succession allowed up to the overlying Pliensbachian pelagites. Two type of carbonate sedimentation have been recognized: in the peritidal and shallow subtidal environments (Calcare Massiccio A) the carbonate production is dominated by microbial activity, while the carbonate sedimentation in a deeper environment of middle to outer ramp (Calcare Massiccio B), is dominated by a bioclastic sedimentation. The evolution from the Calcare Massiccio A to the B can be interpreted as the product of increase of accommodation that in turn produced a backstepping of carbonate facies belt, the photic microbial dominated peritidal facies developed on the persistent Latium-Abruzzi Platform while the bioclastic carbonate production factory settled on the structural highs resulting from the dismembering of the platform by syn-sedimentary tectonic. The bioclastic carbonate factory was not efficient in filling the available accommodation space produced by Sinemurian extensional tectonic. This inefficiency was amplified by the restricted area available for this factory in the small structural highs. These conditions were sufficient to predispose the platform to the drowning without invoke change in the trophic resource or change in the palaeoceanography.

This work is the result of detailed geological mapping and stratigraphic analysis of the Lepidocyclina Limestone in the northern sector of the Majella Mountains (Central Apennines). The Lepidocyclina Limestone represents an informal member of the Bolognano Formation (Chattian to Messinian in age). Four main lithofacies have been recognized: planar cross-bedded grainstone (FA); moderate-angle, cross-bedded grainstone to packstone (FB); sigmoidal cross-bedded grainstone (FC); and bioturbated marly packstone to wackestone (FD). A detailed description of the recognized lithofacies and facies association of the Lepidocyclina Limestone is given in this work, together with an interpretation of the corresponding depositional setting and a discussion of the related larger-scale processes. In summary, the depositional profile of the Lepidocyclina Limestone is consistent with a carbonate ramp, where most of the sediments appear to be parautochthonous in the middle ramp environment and autochthonous-dominated in the outer ramp environment. Palaeocurrent patterns indicate a strong, generally north–west basin-ward direction that affected the middle ramp environment and developed a wide, down-slope migrating dune field. Considering that the warm Oligocene climate of the Mediterranean area was favorable to tropical cyclone development, both in terms of frequency and intensity, it is suggested that return currents generated by strong winds or storms were common on the “Lepidocyclina” carbonate ramp, thus favoring the development of the observed dune field.

Deglacial reefs from Tahiti (IODP 310) feature a co-occurrence of zooxanthellate corals with microbialites that compose up to 80 vol% of the reef framework. The notion that microbialites tend to form in more nutrient-rich environments has previously led to the concept that such encrustations are considerably younger than the coral framework, and that they have formed in deeper storeys of the reef edifice, or that they represent severe disturbances of the reef ecosystem. As indicated by their repetitive interbedding with coralline red algae, the microbialites of this reef succession of Tahiti, however, formed immediately after coral growth under photic conditions. Clearly, the deglacial reef microbialites present in the IODP 310 cores did not follow disturbances such as drowning or suffocation by terrestrial material, and are not “disaster forms”. Given that the corals and the microbialites developed in close spatial proximity, highly elevated nutrient levels caused by fluvial or groundwater transport from the volcanic hinterland are an unlikely cause for the exceptionally voluminous development of microbialites. That voluminous deglacial reef microbialites generally are restricted to volcanic islands, however, implies that moderately, and possibly episodically elevated nutrient levels favored this type of microbialite formation.

The soft bottom of the Mediterranean continental shelf is characterized by a heterozoan skeletal assemblage (sensu [James, N.P., 1997. The cool-water carbonate depositional realm. In: James, N.P., Clarke, J. (Eds), Cool-water Carbonates. Spec. Publ. Soc. Sediment. Geol., vol. 56, pp.1–20.]). Although the contemporary presence of terrigenous and skeletal carbonate sediments has been well established [Tortora, P., 1996. Depositional and erosional coastal processes during the last postglacial sea-level rise: an example from the Central Tyrrhenian continental shelf (Italy). J. Sed. Res. 66, 391–405.; Fornos, J.J., Ahr, W.M., 1997. Temperate carbonates on a modern, low-energy, isolated ramp: the Balearic Platform, Spain. Journal of Sedimentary Research , 67, 364–373.; Fornos, J.J., Ahr, W.M., 2006. Present-day temperate carbonate sedimentation on the Balearic Platform, western Mediterranean: compositional and textural variation along a low-energy isolated ramp. In: Pedley, H.M., Carannante, G. (Eds.) 2006, Cool-water Carbonates: Depositional Systems and Palaeoenvironmental Controls. Geological Society, London, Special Publications, 255, pp. 121–135], the interactions between carbonate and terrigenous–siliciclastic sedimentation has not been documented well enough. A total of 33 surface sediment samples from the Pontinian shelf (Tyrrhenian Sea, central Mediterranean) have been analysed. Sampling stations range from 15 to 250 mwd (meter water depth) and are located along five transects (PonzaW, PonzaNW, Ponza NE, Ponza E, Zannone), plus four samples collected around Palmarola Island. Sectors colonized by seagrass meadows have not been sampled. A total of 6 sedimentary facies (F) and 10 microfacies (mf) have been recognized by using component analyses, grain size percentage, sorting, carbonate content and authigenic mineralization rate. These facies and microfacies represent the Pontian Islands shelf sedimentation, in the interval between the upper infralittoral and the epibathyal zones that represent shelf-break and upper slope sedimentation. The Maerl facies (F4a,b; mf4a,b) and the skeletal sands (F2a,b; mf2a1, mf2a2, mf2b) fall within the circalittoral zone. The circalittoral zone in the water depth interval between 82 m and 112 m display relict facies (F6, mf6). Finally facies F5 (Siliciclastic sands) includes subfacies F5b (mf5b), located in the circalittoral zone at depths of 49 to 101 mwd and restricted to the western and eastern sectors of Ponza, and subfacies F5a in the upper infralittoral zone (15 mwd/25 mwd) where erosional processes prevail. Carbonate content analyses indicate that maximum carbonate production on the Pontinian shelf took place in the 60–80 mwd interval. Facies F4 (Maerl) represents the environment characterized by the highest carbonate production rates. In the Pontian area siliciclastic–carbonate mixing took place in the infralittoral zone and in the lower circalittoral zone. In the infralittoral zone erosional processes on the rocky shoreline produced lithoclasts and vulcanoclastic deposits that were reworked by wave-induced near-shore currents. In the lower circalittoral zone the prolific production by photic biota (red algae) ends, while skeletal remains of the aphotic environment mixes with planktonic sediments characterized by low carbonate values. Sand (63 μm–2 mm) is the dominant grain size class, however gravel-dominated facies (F4 Maerl) are present in water depths (50 to 112 mwd) which are significantly below the storm wave base. Glauconite mineralization appears on the Pontinian shelf from 50 mwd and increases in abundance along the deeper bathymetries. The compositional characteristics of relict facies F6 shows the concurrence of biota assemblages of the infralittoral and circalittoral zones, likely representing the record of the last Holocene transgressive event (18 ky) and expressed by the overlapping of components of different environments.

The presence of foramol, rhodalgal and bryomol skeletal grain associations in ancient shallow-marine limestones is commonly interpreted as evidence for non-tropical palaeoclimate, despite temperature being only one of several factors influencing skeletal grain associations. Such interpretations neglect the multitude of factors other than temperature that influence carbonate-producing biota. These include nutrients, water energy, water transparency, depth of the sea floor, salinity, oxygen, Ca2+ and CO2 concentrations, Mg/Ca ratio, alkalinity, substrate requirements, competitive displacement as well as biological and evolutionary trends. This uniformitarian approach also disregards the probability that conditions of present-day biological systems may not be representative of past conditions of analogous systems. Here, the importance of considering these other factors is illustrated through two examples of carbonate platforms in the western Mediterranean. These platforms are dominated by foramol, rhodalgal and bryomol associations of Miocene age in spite of having formed in tropical conditions. The platforms discussed are: (1) the Lower Tortonian ramp on Menorca, Balearic Islands; and (2) the Lower–Middle Miocene ramps of the central Apennines, Italy. Evidence for tropical conditions in the Mediterranean during the period of growth of these platforms is provided by species of red algae and larger foraminifera, by data from coeval continental basins and by global oxygen isotope data.

The lower Miocene Latium–Abruzzi platform was a low-angle ramp that developed under tropical-to-subtropical conditions, but was dominated by bryomol and rhodalgal sediment associations. The Aquitanian to Serravallian sequence described here paraconformably overlies the Cretaceous limestones. It consists of a lowstand systems tract, a transgressive systems tract and a highstand systems tract. Based on facies analysis and on the light dependence of biotic associations, the ramp is divided into three parts: an inner ramp, a middle ramp and an outer ramp. The inner ramp facies are represented by a few metres of coral framestone, rhodolith floatstone–rudstone and balanid macroids floatstone without wave-related structures. The middle ramp consists of structureless bioclastic grainstone to packstone, floatstone and rudstone with rhodoliths and larger foraminifera. The outer ramp facies—proximal sector—are composed of crudely stratified bryozoan-dominated packstone to floatstone which extend over the whole platform. The outer ramp facies—intermediate sector—are represented by wackestone, packstone and rarely grainstone with foraminifera and echinoid fragments. The final depositional profile of the ramp was strongly influenced by the main organisms producing sediment. During the lowstand, the resulting profile is a ramp type. During the transgressive phase, the rapid spreading of the outer ramp facies belt, as a consequence of the enhanced productivity of the light-independent biota, is believed to be promoted by a change from oligotrophic to eutrophic conditions. Climate and/or tectonics are presumed to have played an important role in continental runoff and then in the nutrients delivery. During the highstand phase, the system returns to rates of production uniform throughout the platform. The high rates of carbonate production occurring in the aphotic zone are quite unusual in tropical settings and represent a provocative trend in apparent contrast with the common idea about the locus of the most significant carbonate production, as derived from the “tropical model”. The example described here shows that carbonate production and accumulation below the photic zone might be higher than in the shallow euphotic zone even in tropical conditions.

This paper presents the results of a high-resolution analysis of Upper Cretaceous shallow-water limestones in the northeast sector of the Lepini Mountains (Central Apennines, Italy) that belong to the Latium-Abruzzi platform domain. The studied succession is entirely referred to as the "Accordiella conica & Rotorbinella scarsellai Biozone". The analyzed Coniacian-Campanian succession is primarily characterized by three lithofacies associations (LF-A, LF-B, LF-C) deposited on an open shelf. The intertidal and shallow-subtidal environments are characterized by mudstone to wackestone and laminated bindstone (LF-C), whereas in the low to moderate energy environments of the inner shelf there developed rudist biostrome (rudist pillarstone) and rudist rudstone to floatstone (LF-A). A lithofacies association dominated by cross-bedded grainstone (LF-B) represents the reworking of bioclastic grains (rudist fragments) derived from the areas of the shelf colonized by rudist biostrome; lime-sand shoals related to storm channels passed into submarine dunes in an open-shelf setting. Correlation of the five investigated stratigraphic sections shows how the recognized LF are laterally associated to form a facies mosaic over a few hundred meters. The stratigraphic architecture shows five intervals (I-V) each of which is dominated by one or two LF. Interval I is intensely dolomitized. The following intervals (II and III) record a gradual increase in hydrodynamic energy as evidenced by the presence of rudist biostromes passing upward into cross-bedded grainstone. An increase in mud-supported textures in the interval IV suggests more restricted conditions, which were terminated by a period of emergence. More open-marine conditions in the final interval (V) are shown by the dominance of LF-A and LF-B. © 2014 Springer-Verlag Berlin Heidelberg.

During the Early Miocene, coincident with the Sardinia–Corsica block rotation, mixed carbonate–siliciclastic sediments of the Cala di Labra Formation were deposited on the southern margin of the Bonifacio Basin (southeastern Corsica, France). The Burdigalian marine transgression is spectacularly represented by a peculiar coral bioconstruction, unconformably lying on the eroded Variscan granitic basement. Superb exposures allowed detailed, three-dimensional field mapping, lithofacies analysis, and characterization of the Cala di Labra coral bioconstruction. As a result of the extremely irregular and articulated substrate, the coral buildup appears as an organized lens-shaped structure, and its core is constituted by a relatively dense coral domestone with a moderate increase of platy corals in the upper part. A coral rubble associated with granitic cobbles and pebbles is locally present at the base. The inter-coral sediment consists of poorly sorted bioclastic wackestone to packstone. Results from this study clearly show evidence for the occurrence of a former submerged granitic substrate that, as very rarely documented in the geological record, is here interpreted as the subtidal substrate for growth of a small bioconstruction under relatively high energy and clear water conditions. The Cala di Labra bioconstruction is overlain by a fining-upward quartzose conglomerate and sandstone succession interpreted as deposited in a coastal setting near fluvial point sources. The demise of coral growth was caused by a regressive event and by the consequent quite-sudden burial and related changes of trophic conditions.

This study presents a detailed facies analysis and paleodepth reconstruction of a coral-rich mixed siliciclastic-carbonate system Burdigalian in age, outcropping in the northern sector of Sardinia (Capo Testa). Excellent exposures of continuous sea-cliff outcrops around the southwestern and northeastern area of Capo Testa promontory allowed us to: (1) trace stratigraphic surfaces; (2) document stratal geometries; (3) discern details of the lithofacies and, (4) reconstruct the paleodepths of the different depositional environments. A total of seven sedimentary facies has been recognized and interpreted: siliciclastic conglomerate and coarse bioclastic sandstone (F1), fine- to medium-grained hybrid sandstone (F2, scleractinian coral domestone (F3), bioclastic packstone to floatstone with platy Porites (F4), red algae floatstone to rudstone (F5), larger benthic foraminifers (LBF) bioclastic rudstone floatstone in a packstone matrix (F6), molluscan floatstone in a bioclastic packstone matrix (F7). The investigated system is characterized by nearshore to shoreface deposits with a conspicuous terrigenous content that grades seaward into deeper zones where coral patch-reefs developed in association with adjacent areas colonized by seagrass meadows. The more distal facies are constituted by scattered encrusting tabular colonies of Porites in growth position occurring in a deeper and lower-energy environment. The paleodepth interval that is observed in the Capo Testa outcrop ranges from 0 to 50 m.

The Oligocene represents a key interval during which coralline algae became dominant on carbonate ramps and luxuriant coral reefs emerged on a global scale. So far, few studies have considered the impact that these early reefs had on ramp development. Consequently, this study aimed at presenting a high-resolution analysis of the Attard Member of the Lower Coralline Limestone Formation (Late Oligocene, Malta) in order to decipher the internal and external factors controlling the architecture of a typical Late Oligocene platform. Excellent exposures of the Lower Coralline Limestone Formation occurring along continuous outcrops adjacent to the Victoria Lines Fault reveal in detail the three-dimensional distribution of the reef-associated facies. A total of four sedimentary facies have been recognized and are grouped into two depositional environments that correspond to the inner and middle carbonate ramp. The inner ramp was characterized by a very high-energy, shallow-water setting, influenced by tide and wave processes. This setting passed downslope into an inner-ramp depositional environment which was colonized by seagrass and interfingered with adjacent areas containing scattered corals. The middle ramp lithofacies were deposited in the oligophotic zone, the sediments being generated from combined in situ production and sediments swept from the shallower inner ramp by currents. Compositional characteristics and facies distributions of the Attard ramp are more similar to the Miocene ramps than to those of the Eocene. An important factor controlling this similarity may be the expansion of the seagrass colonization within the euphotic zone. This expansion may have commenced in the Late Oligocene and was associated with a concomitant reduction in the aerial extent of the larger benthonic foraminifera facies. Stacking-pattern analysis shows that the depositional units (parasequences) at the study section are arranged into transgressive–regressive facies cycles. This cyclicity is superimposed on the overall regressive phase recorded by the Attard succession. Furthermore, a minor highstand (correlated with the Ru4/Ch1 sequence) and subsequent minor lowstand (Ch2 sequence) have been recognized. The biota assemblages of the Attard Member suggest that carbonate sedimentation took place in subtropical waters and oligotrophic to slightly mesotrophic conditions. The apparent low capacity of corals to form wave-resistant reef structures is considered to have been a significant factor affecting substrate stability at this time. The resulting lack of resistant mid-ramp reef frameworks left this zone exposed to wave and storm activity, thereby encouraging the widespread development of coralline algal associations dominated by rhodoliths.

Analyses of facies associations and biotic assemblages integrated with backstripping analysis are presented to improve understanding of the development of a shallow water Miocene carbonate ramp in the Central Apennines (Italy), with special reference to the relationships between tectonic subsidence and the internal architecture of the ramp. Subsidence curves were calculated for six measured sections located in different sectors of the platform. Dating is derived from Sr isotope analyses (from previous studies) and regional correlations. Corrections for eustasy and paleobathymetry were deduced from biota and facies analyses. The subsidence curves show rates that vary both in space and time. By analysing the vertical motions in different sectors of the ramp over a fixed time span (Burdigalian to Tortonian), it was possible to evaluate the control on platform architecture exerted by tectonically induced changes in sea-floor bathymetry and highlight the effects of tectonic migration. Most analysed sites experienced a short period of tectonic uplift or stability followed by a period of slow subsidence. This preceded increased subsidence which resulted in drowning of the shallow-water carbonate platform. The stability/uplift is progressively younger towards the north-eastern sectors that correspond to progressively more external zones of the foreland relative to the Apenninic orogenic belt. The subsequent drowning is related to the diachronous down-flexure of the Adriatic lithosphere due to its eastward retreating subduction under the Apennines. The small magnitude of the uplift suggests that the formation of a foreland bulge due to subduction-related flexure of the Adriatic plate was probably not the responsible mechanism. Hence, this uplift is related to the development of proto-thrusts or to the propagation of compressive stresses in the foreland. These vertical motions influenced the geometry of the platform during the 17.5–16 Ma stage. During this period the platform was characterised by exceptional progradation of the bryomol-dominated proximal outer ramp facies belt. This rapid spreading may be induced by the combined effect of increased eutrophic conditions and a contemporaneous decrease in the sea-floor bathymetry resulting from the tectonic uplift. From the Tortonian onwards, when the platform became involved in the eastward migrating foredeep system, the tectonic subsidence curve records a short period of fast tectonic subsidence rates followed by a period of slow subsidence or slight uplift during basin drowning and infilling, respectively.

In this work, we investigate the role of hydrocarbons in changing the petrophysical properties of rocks by merging laboratory measurements, outcrops characterization, and subsurface data focusing on a carbonate-bearing reservoir (Bolognano Formation) of the Majella massif. This reservoir represents an interesting analogue for subsurface carbonate reservoirs and is made of high porosity (up to 32%) ramp calcarenites saturated by hydrocarbon in form of bitumen. We have characterized in the laboratory density, porosity, compressive strength, Young's modulus and Poisson's ratio of both clean and heavy oil-bearing carbonate rocks of the Bolognano Formation. At ambient pressure the Vp are in the range of 3.49 km/s to 5.06 km/s for clean samples with an inverse relation with porosity, whilst the Vp range for HHC-bearing rocks are from 3.56 km/s to 4.56 km/s without any relation with measured porosity. These data show that porosity and presence of HHCs within the samples both affects seismic waves velocity. In particular, Vp and the derived dynamic Young's modulus generally strongly decrease with increasing porosity for clean samples and, for a fixed porosity, tends to increase with the presence of heavy-oil. This is confirmed also at higher (up to 100 MPa) confining pressure that has not a significant effect on Vp and Vs. Cyclic loading-unloading experiments show that the average compressive strength is 25 MPa and 38 MPa and average static Young's modulus are 5.7 GPa and 9.9 GPa, for clean and HHC-bearing samples respectively. Additionally, the permanent strain is always larger for clean samples. Field work, consisting in measuring fracture orientation in 11 outcrops of the same lithology, shows that both heavy oil-bearing and clean outcrops are characterized by two main trends NW-SE and NNE-SSW. However, the spacing data show that heavy-oil-bearing outcrops are much less fractured respect to clean outcrops. This suggests, assuming that the deformation occurred under the same stress state, that heavy oil-bearing outcrops are stiffer respect to clean outcrops, as supported by the laboratory measurements. We thus infer that in the study area hydrocarbons migration predates the last stage of deformation, limiting the fracturing in bitumen-bearing portions of the Bolognano Formation. At regional scale, the presence of buried oil fields located few kilometres away from the heavy-oil-bearing outcrops and pertaining to the same petroleum system, suggests a good lateral continuity of the reservoir giving clues about the key role played by primary porosity in the secondary migration that acted in this area.

Bryozoan–stromatolite associations (bryostromatolites) formed conspicuous reef structures throughout the Sheinwoodian (Wenlock) to Ludfordian (Ludlow) stratigraphy on Gotland but have not been described so far. They are mainly composed of encrusting bryozoans forming a complex intergrowth with porostromate and spongiostromate microbes and are different from the abundant stromatoporoid–coral–algal reefs with respect to their composition. In the bryostromatolite different growth stages can be identified. The observed succession can be taken as evidence for cyclic environmental changes during reef formation. Stenohaline reef‐dwelling organisms, such as echinoderms, sponges, corals and trilobites, indicate fully marine salinities. Ten localities exposing bryostromatolites were discovered. Individual bryostromatolites are small with few decimetres up to one metre in size, and occur solely in shallow marine areas. Common features of these reefs on Gotland are cauliflower‐like growth, a high bryozoan diversity, a high abundance of phosphatic fossils and components such as bryozoan pearls and inarticulate phosphatic brachiopods, enhanced bioerosion, Palaeomicrocodium crusts, vadose silt and gypsum pseudomorphs. The high abundance of Palaeomicrocodium, as well as the alternation with other crust‐forming contributors, suggest that it could have been formed directly at the palaeo‐sea surface, probably in times of minor but high‐frequency sea‐level fluctuations. Vadose silt and pseudomorphs after gypsum in reef cavities indicate subaerial exposure shortly after reef growth. The high amount of phosphatic components indicates a high nutrient input, probably by dust. All bryostromatolites were formed in times of strongly elevated δ13C values. The unusual combination of sedimentological and palaeoecological features, as well as their occurrence exclusively during strong positive δ13C excursions, are evidence that the bryostromatolite development responded to climatic/oceanographic changes, which may have played an important role in reef control., Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659, Schmauser Stiftung