Seismic re ection (2D/3D), borehole and bathymetric data have led to the recognition of a new gra... more Seismic re ection (2D/3D), borehole and bathymetric data have led to the recognition of a new gravitational complex in the Squillace Embayment. Named as Squillace Complex, it has a NE-striking headwall connected to a basal detachment zone formed between Messinian evaporites and Tortonian shales. Its geometry changes to a W to E predominant movement in its toe region. The Squillace Complex is marked by the presence of sinuous and continuous sea oor scarps just a few kilometers offshore (minimum distance 1.5 km), which occur over a lobate-shaped elongated morphological high. Seismic-well ties show that the complex initiated its movement in the Zanclean and continued for ~ 2 Ma into the Gelasian, with an average rate of 1.6 mm /y. Movement ceased in the Calabrian but resumed soon later during Middle Pleistocene, until the present day, at a relative slower rate of 0.4 mm/y. The onset of gravitational collapse in the Squillace Complex is correlated with discrete contractional/transpressional events, under episodes of basin shortening and temporary stopping of Calabrian Arc migration, as well as during episodes of tectonic uplift after 0.45 Ma. Conversely, its arrest during the Calabrian is linked to slab rollback and subduction of the Ionian plate under the arc.
The eastern Mediterranean has been the locus of catastrophic earthquakes and related tsunamis (... more The eastern Mediterranean has been the locus of catastrophic earthquakes and related tsunamis (e.g., the 365 Crete and 1222 Cyprus earthquakes). The primary sources of these seismic events are structures related to the subduction of the Nubian Plate along the Hellenic and Cyprus arcs. A detailed identification and description of the potential tsunamigenic sources are required as part of an assessment of earthquake and tsunami hazards. Here we focus on the Cyprus Arc region, in which the oceanic crust is still subducting beneath the Anatolian Plate in the west, whereas in the eastern sector, the oceanic crust has been completely subducted, and the lower plate consists of thinned continental crust. The rates of shortening are higher in the western sector than in the east. During recent decades, new data from extensive hydrocarbon exploration have allowed us to image structures that deform the seafloor and influence the shape of the recent basins in the eastern sector. The Latakia R...
Field analogues illustrating the early stage of deformation of shortening structures in salt‐bear... more Field analogues illustrating the early stage of deformation of shortening structures in salt‐bearing orogenic fold‐and‐thrust belts are not yet well illustrated in literature. The relatively young Messinian salt of the Algerian basin could represent a good case example of such systems. The Algerian Basin is a deep‐water Miocene back‐arc basin including a layer of mobile Messinian evaporites up to 2 km thick. The Messinian salt was deposited in an already inverted basin, after its extensive stage. Its inversion initiated in the Tortonian, with a N‐NW shortening induced by the north‐westward motion of the African plate. In this study, we use new 2D multichannel seismic data to identify, classify and map salt structures throughout the central Algerian Basin and re‐assess its structural style. We interpret contractional salt tectonic structures, such as buckle folds, squeezed diapirs and related salt sheets as evidence of regional thick‐skinned shortening episodes. We conclude that hori...
D.R.E. Am Italia - ISPRA, Servizio Geologico d'Italia, 2020
RIASSUNTO-La presenza di fluidi nei sedimenti del Golfo di Trieste (Nord Adriatico) è caratterizz... more RIASSUNTO-La presenza di fluidi nei sedimenti del Golfo di Trieste (Nord Adriatico) è caratterizzata da manifestazioni superficiali che sono state individuate nei dati di sismica ad alta risoluzione. In particolare nell'area a sud-ovest di Grado sono stati identificati sei siti con evidenze di accumulo di fluidi nei sedimenti, dispersione di fluidi nella colonna d'acqua, e presenza sul fondo mare di affioramenti rocciosi la cui genesi si ipotizza sia legata alla precipitazione di carbonato di calcio metano-derivato. PAROLE CHIAVE: Adriatico, Golfo di Trieste, emissione fluida, fondale marino, fluidi, gas, migrazione, profilo geofisico. ABSTRACT-The presence of fluids in the sediments of the Gulf of Trieste (Northern Adriatic) produces surface occurrences that have been identified by high resolution seismic data. In particular, southwest of Grado, six sites have been pinpointed with evidence of accumulation of fluids within the sediment, dispersion of fluids in the water column, and presence on the sea bottom of rocky outcrops whose genesis is assumed to be linked to the precipitation of calcium carbonate methane-derived.
D.R.E. Am Italia - ISPRA, Servizio Geologico d'Italia, 2020
RIASSUNTO-L'analisi dei profili acustici chirp e dei dati di morfobatimetria multibeam acquisiti ... more RIASSUNTO-L'analisi dei profili acustici chirp e dei dati di morfobatimetria multibeam acquisiti durante diverse campagne della N/R OGS Explora e la loro correlazione con i profili sismici multicanale, hanno messo in evidenza la presenza di fenomeni di gas-seepage, di sistemi di frattura e di domi salini profondi presenti nell'Adriatico Centrale. La loro distribuzione mostra una stretta relazione tra i loro reciproci sviluppi.
The Western Mediterranean Sea is a natural laboratory to address questions about the formation an... more The Western Mediterranean Sea is a natural laboratory to address questions about the formation and evolution of continental margins and the relationship between surface and deep processes. The evaporites deposited during the late Miocene's Messinian Salinity Crisis (MSC) strongly impact its sedimentological and geomorphological evolution. Hereafter, we present a compilation of some of the main regional seismic stratigraphic markers throughout the Western Mediterranean Sea. We provide in xyz format (z in second twt) the original, not interpolated, points interpretation of the following horizons: i) Acoustic basement, ii) Base and Top of the MSC salt, also known as Mobile Unit (MU), iii) base Pliocene and iv) Seafloor. The available reflection seismic dataset, coming from a collaboration between French, Spanish, Algerian and Italian research institutes, covers most of the Western Mediterranean sub-basins with the exception of the Ligurian Basin. This compilation is currently the m...
The Adriatic Sea hosts important historically explored hydrocarbon provinces. In the northern are... more The Adriatic Sea hosts important historically explored hydrocarbon provinces. In the northern areas, the main sources of hydrocarbon productivity are from biogenic gas reservoirs located in Quaternary thick deltaic depositional systems related to the Apennine and Dinaric foreland domain. In addition, Mesozoic thermogenic oil plays were identified and exploited in the Southern areas. Herein, we use basin and petroleum systems modelling (BPSM) techniques to investigate the still unproved thermogenic hydrocarbon potential of deep Mesozoic basins in the North Adriatic Sea and to correlate the results with the sedimentary evolution of proven petroleum systems in the Central and South Adriatic, both in the Italian and Croatian offshore areas. We used the regional CROP-M16 marine seismic profile in the eastern segment of the study area, where it cuts the western margin of the Dinaric carbonate platform and reaches the pelagic domain of the Umbria-Marche basin intersecting the Barbara isolated platform (Figure 1). We reprocessed the 2D seismic data set to obtain the correct dips and depths of the geological structures from a depth-migrated profile. During the interpretation phase, we integrated the information from profile CROP-M16 with the orthogonal CROP-M17B and C profiles that are intersecting the Alessandra-001 exploration well. The interpretation allowed a detailed analysis of the main lithological discontinuities and of the fault system. We used the interpreted features together with the petrophysical parameters inferred by the available wells in the area and by literature, for 2D petroleum systems modelling. Our simulation integrated the available information to produce a set of possible scenarios of basin development, with the objective to understand the maturation and migration of hydrocarbons.
The geological genesis, evolution and depositional settings of the Mediterranean Sea have been st... more The geological genesis, evolution and depositional settings of the Mediterranean Sea have been studied for decades by the scientific community which, for some aspects, combines research with the Petroleum Industry to enhance hydrocarbon exploration. It is in these circumstances that the geophysical study hereafter described was conceived. Two research bodies and a multi-client geophysical company have been involved in this project: the Department of Mathematics and Geosciences of the University of Trieste (DMG), the Italian National Institute of Oceanography and Experimental Geophysics (OGS) and TGS Geophysical Company ASA. The paper presents a geophysical analysis, based on interpretation of ten 2D multichannel seismic reflection profiles located in the Eastern Sardo-Proven\ue7al basin of the North-Western Mediterranean crossing domains from the outer West Sardinian shelf to the deep basin (Fig.1A,B). The post-stack time migrated lines have a total length of 1545 km and cover an area of about 35.000 km2. The profiles belong to three distinct datasets (WMR, WS, CROP, location on Fig.1A) recorded by different geophysical projects, each of them using specific acquisition parameters. The five WMR (West Mediterranean Regional) profiles were provided by TGS. The three WS (West Sardinia) profiles were acquired by their owner OGS. The two CROP (CROsta Profonda) lines, provided by the DMG, were originally sponsored by AGIP-ENI, CNR & ENEL. The presence of the Messinian rock salt, that within a sedimentary sequence produces halokinesis and scatters most of the acoustic energy, suggested the reprocessing in time domain of a part of a CROP seismic profile in order to improve the imaging of those reflections that are strongly deformed or masked. To enhance image accuracy assessing size and location of geological structures beneath the Messinian salt, a pre-stack depth migration (PSDM) was executed using the Kirchhoff algorithm. The processing outcomes were useful not only to enhance and better define the entire seismic interpretation on the available datasets, but also allowed the evaluation of the peculiar lithologic/stratigraphic conditions of the basin. The integration of the three datasets gave better coverage of the study area and supplied complementary information thanks to different resolutions. On the whole, the work presented hereafter aimed at better knowledge of the depositional history, starting from the Messinian Age, of the North-Western Mediterranean basin
The Adriatic basin represents one of several restricted basins located in the Mediterranean Area.... more The Adriatic basin represents one of several restricted basins located in the Mediterranean Area. It consists of the foreland of three different orogenic belts: the Dinarides to the East, active during the Eocene, the Southern Alps to the North, active since the Cretaceous time, and the Apennines to the West, active since the Paleogene. The Apennines had a primary role during the Messinian Salinity Crisis (MSC), conditioning the connection between the Adriatic basin, the Ionian basin, and the proto-Tyrrhenian basin. During the Messinian, the present Adriatic Sea was characterized by shallow water domains, where gypsum evaporites initially deposited and often successively incised or outcropped.
COST-ANR MEDSALT Symposium, 24-28 October 2016, Palermo, Italy.-- 1 pageThis study is based on mu... more COST-ANR MEDSALT Symposium, 24-28 October 2016, Palermo, Italy.-- 1 pageThis study is based on multibeam bathymetry and multi-channel seismic reflection data collected during Eurofleets R/V OGS Explora, Cruise No. E12 (SALTFLU), Valencia (Spain) 22/06 - 04/07/2012. Modelling of overpressure evoltion is based on the resulting stratigraphy. The study area encompasses proposed drill sites BAL-02 and BAL-02 of IODP pre-proposal 857B-Pre, Deep-Sea Records of the Messinian Salinity Crisis (DREAM), proposed by J. Lofi et al in 2015. We identify four types of salt-induced abyssal plain sediment deformation structures: (1) a belt of elongated abyssal plain seahills thought to be the attenuated surface expression of salt rollers either produced by reactivated right strike slip faults synthetic to the master fault of the EBE or by differential compaction above such faults; (2) anastomosing knolls in the Menorca Fan area thought to be the product of subsurface salt deformation and gliding triggered by differential sedimentary load; (3) abyssal knolls and seahills spread in the entire abyssal plain across the basin thought to be the product of subsurface salt anticlines and pillows in a relatively more evolved stage of basin evolution affected by basement faulting, perhaps northward propagation of the shortening affecting the Algerian margin; and (4) a small flat topped circular mound in the middle of the abyssal plain interpreted as a mud volcano extruding sediments and fluids of likely pre-Messinian origin. The structures suggest that the crustal transition, not imaged in the seismic data due to intense deformation does not correspond to the Emile Baudot Escarpment (the present day continental tectonically driven continental slope). Rather it is located farther offshore in the deep basin, approximately where intense halokinesis occurs in the abyssal plain, marking the edge of the deep Messinian basin filled with kilometer-thick evaporites. Messinian marginal basins, therefore, are presently located also below the abyssal plain, at the floor of the Emile Baudot Esacarpment. Evidence for sub-salt overpressure is provided by pearchment structures in the deep Messinian basin. A compaction disequilibrium modeling exercise demonstrates that the high sedimentation rate of the thick evaporitic succession in the deep Messinian basin, may indeed generate considerable overpressure, persisting today (overpressure coefficient up to 0.8). However, the reduced evaporite thickness in the marginal basins reduces considerably the likelihood of sub-salt overpressure (overpressure coefficient up to 0.2). Therefore, we conclude that marginal basins belong to different geological domains compared to the deep basin, being the difference given by different crustal structure, evaporite thickness, in some cases evaporite composition (absence of halite layer), and pore pressure regime below and within the evaporitic formations. An upward pore water expulsion system is inferred through the Plio-Quaternary sedimentary cover induced by gypsum dehydration to anhydritePeer Reviewe
Since the discovery of widespread Salt and Gypsum deposits of the Mediterranean Sea in the early ... more Since the discovery of widespread Salt and Gypsum deposits of the Mediterranean Sea in the early '50s, a large number of scientists tried to unravel the mystery related to this huge deposition of evaporites. Evidence of the later so-called "Messinian Salinity Crisis" (MSC) are largely distributed all around the Mediterranean Basin and widely studied. Although gypsum deposits were recognized in some peripheral or marginal basins (e.g. Sorbas Basin in Spain, Northern Apennines in Italy), mechanism of their deposition and formation are still uncertain. Particularly, the so-called Gessoso-Solfifera formation (GS Fm) was recognized in the '50s by Selli in several outcrops in Northern Apennines and it is nowadays well known and mapped in the onshore outcrops. A regional analysis in the Adriatic Sea is still incomplete, even though a large amount of data is available (2D multichannel seismic lines, boreholes, exploration reports). In the Adriatic Sea, the MSC event can be recognized in the 2D seismic lines as actual thin deposit (maximum GS Fm thickness of about 120 ms TWT) or Messinian erosional surface (MES). In both cases, a strong and clear reflector at the Pliocene base is picked and calibrated by the boreholes reaching its depth. Along the main part of the available seismic profiles it is sometimes very hard to ascribe this strong reflector to the MES or to the presence of a thin gypsum layer. Calibration of 2D seismic lines with boreholes, also integrated by physical properties derived from geophysical well logs and core data) of the Plio-Quaternary sediments, allowed a detailed seismic facies analysis useful for this purpose. A structural map of the Plio-Quaternary base describes the Plio-Quaternary deformation that affected the study area mainly as Apennine foreland. The thickness map of the GS Fm describes the subsidence and the erosional effect occurred during the MSC. Both these maps are here presented as a first result of a regional study, that intends cover the whole Adria offshore.
The Messinian Salinity Crisis (MSC), which widely affected the whole Mediterranean basin, induced... more The Messinian Salinity Crisis (MSC), which widely affected the whole Mediterranean basin, induced rapid and spectacular palaeoenvironmental changes. It led to a major erosion of the onshore areas and the upper parts of the continental shelves and slopes, as well as important evaporitic deposits in the offshore deep basins. The Corsica Basin belongs to the so-called "intermediate-depth basin" type because of its location between the coastal plainshelf area of East Corsica and deeper marine basins in the northern Tyrrhenian Sea. The MSC event took place in the Corsica Basin during a period of active regional tectonics, contemporaneous with the opening of the Tyrrhenian Sea, as well as during the development of the Corsica Basin and the Elba-Pianosa Ridge. Based on the interpretation of high-resolution seismic reflection profiles and a new 1:250,000 scale synthetic geological map, we establish that the MSC is recorded in the Corsica Basin through the occurrence of two sedimentary formations bounded by three remarkable surfaces. These seismic markers suggest local and temporal variations in relative water level and associated depositional environments that differ between the north and south of the Corsica Basin. During the MSC, the northern sector (Golo Basin) was emerged, whereas the southern sector (Orbo Basin) was often flooded or submerged. In the Orbo Basin, the deposits record both an episode of intra-MSC climate change and regional tectonic events. During the MSC, the Corsica Basin was a perched lake, isolated from the deeper Tyrrhenian basins. The connection with the Tyrrhenian basins was re-established during the final stages of the MSC, before the catastrophic Pliocene reflooding, initiated by retrogressive Thinon et al. In press 2016-Seismic markers of the Messinian Salinity Crisis in an intermediate-depth basin: data for understanding the Neogene evolution of the Corsica Basin (Northern Tyrrhenian Sea)-Marine and Petroleum Geology 2 erosion during a relative lowstand. An extensive network of incised valleys was thus established in the Orbo basin, allowing the drainage of the Corsica Basin southwards into the deeper Tyrrhenian basins. These markers record the active regional tectonic context throughout the MSC. The Orbo basin was strongly subsident along its western rim, while its eastern rim was uplifted. In turn, the Golo basin subsided from middle Pliocene times onwards, while the northern, eastern and southern edges of the Corsica Basin were deformed and uplifted.
Introduction. We present a comparison between two multichannel seismic datasets acquired across t... more Introduction. We present a comparison between two multichannel seismic datasets acquired across the passive margins of the west Mediterranean sea: the west Sardinia continental margin extending in the east Sardo-Provençal basin and the South Balearic continental margin extending in the northwestern Algero-Balearic basin. The two margins bear in common the origin from continental rifting, but underwent different geodynamic histories and are not coeval. The Sardo-Provençal basin opened following the Oligocene-Early Miocene breakup of the European plate and anticlockwise rotation of the Sardinian block. According to Mauffret et al. (2004) this phase ended in the early Miocene (16 Ma), when the opening of the Algero-Balearic basin started to open as a result of rifting between the Balearic Promontory and the African margin until the Tortonian (8 Ma). The Messinian Salinity Crisis (MSC) affected the whole Mediterranean basin, with deposition of evaporitic sequences in the deep basins, lower continental slopes, and in several shallower marginal basins; usually, in the continental margins, the MSC originated noticeable erosional truncations that locally cause important hiatuses in the pre-Messinian sedimentary sequences, covered by the Plio-Quaternary sequence.
Seismic re ection (2D/3D), borehole and bathymetric data have led to the recognition of a new gra... more Seismic re ection (2D/3D), borehole and bathymetric data have led to the recognition of a new gravitational complex in the Squillace Embayment. Named as Squillace Complex, it has a NE-striking headwall connected to a basal detachment zone formed between Messinian evaporites and Tortonian shales. Its geometry changes to a W to E predominant movement in its toe region. The Squillace Complex is marked by the presence of sinuous and continuous sea oor scarps just a few kilometers offshore (minimum distance 1.5 km), which occur over a lobate-shaped elongated morphological high. Seismic-well ties show that the complex initiated its movement in the Zanclean and continued for ~ 2 Ma into the Gelasian, with an average rate of 1.6 mm /y. Movement ceased in the Calabrian but resumed soon later during Middle Pleistocene, until the present day, at a relative slower rate of 0.4 mm/y. The onset of gravitational collapse in the Squillace Complex is correlated with discrete contractional/transpressional events, under episodes of basin shortening and temporary stopping of Calabrian Arc migration, as well as during episodes of tectonic uplift after 0.45 Ma. Conversely, its arrest during the Calabrian is linked to slab rollback and subduction of the Ionian plate under the arc.
The eastern Mediterranean has been the locus of catastrophic earthquakes and related tsunamis (... more The eastern Mediterranean has been the locus of catastrophic earthquakes and related tsunamis (e.g., the 365 Crete and 1222 Cyprus earthquakes). The primary sources of these seismic events are structures related to the subduction of the Nubian Plate along the Hellenic and Cyprus arcs. A detailed identification and description of the potential tsunamigenic sources are required as part of an assessment of earthquake and tsunami hazards. Here we focus on the Cyprus Arc region, in which the oceanic crust is still subducting beneath the Anatolian Plate in the west, whereas in the eastern sector, the oceanic crust has been completely subducted, and the lower plate consists of thinned continental crust. The rates of shortening are higher in the western sector than in the east. During recent decades, new data from extensive hydrocarbon exploration have allowed us to image structures that deform the seafloor and influence the shape of the recent basins in the eastern sector. The Latakia R...
Field analogues illustrating the early stage of deformation of shortening structures in salt‐bear... more Field analogues illustrating the early stage of deformation of shortening structures in salt‐bearing orogenic fold‐and‐thrust belts are not yet well illustrated in literature. The relatively young Messinian salt of the Algerian basin could represent a good case example of such systems. The Algerian Basin is a deep‐water Miocene back‐arc basin including a layer of mobile Messinian evaporites up to 2 km thick. The Messinian salt was deposited in an already inverted basin, after its extensive stage. Its inversion initiated in the Tortonian, with a N‐NW shortening induced by the north‐westward motion of the African plate. In this study, we use new 2D multichannel seismic data to identify, classify and map salt structures throughout the central Algerian Basin and re‐assess its structural style. We interpret contractional salt tectonic structures, such as buckle folds, squeezed diapirs and related salt sheets as evidence of regional thick‐skinned shortening episodes. We conclude that hori...
D.R.E. Am Italia - ISPRA, Servizio Geologico d'Italia, 2020
RIASSUNTO-La presenza di fluidi nei sedimenti del Golfo di Trieste (Nord Adriatico) è caratterizz... more RIASSUNTO-La presenza di fluidi nei sedimenti del Golfo di Trieste (Nord Adriatico) è caratterizzata da manifestazioni superficiali che sono state individuate nei dati di sismica ad alta risoluzione. In particolare nell'area a sud-ovest di Grado sono stati identificati sei siti con evidenze di accumulo di fluidi nei sedimenti, dispersione di fluidi nella colonna d'acqua, e presenza sul fondo mare di affioramenti rocciosi la cui genesi si ipotizza sia legata alla precipitazione di carbonato di calcio metano-derivato. PAROLE CHIAVE: Adriatico, Golfo di Trieste, emissione fluida, fondale marino, fluidi, gas, migrazione, profilo geofisico. ABSTRACT-The presence of fluids in the sediments of the Gulf of Trieste (Northern Adriatic) produces surface occurrences that have been identified by high resolution seismic data. In particular, southwest of Grado, six sites have been pinpointed with evidence of accumulation of fluids within the sediment, dispersion of fluids in the water column, and presence on the sea bottom of rocky outcrops whose genesis is assumed to be linked to the precipitation of calcium carbonate methane-derived.
D.R.E. Am Italia - ISPRA, Servizio Geologico d'Italia, 2020
RIASSUNTO-L'analisi dei profili acustici chirp e dei dati di morfobatimetria multibeam acquisiti ... more RIASSUNTO-L'analisi dei profili acustici chirp e dei dati di morfobatimetria multibeam acquisiti durante diverse campagne della N/R OGS Explora e la loro correlazione con i profili sismici multicanale, hanno messo in evidenza la presenza di fenomeni di gas-seepage, di sistemi di frattura e di domi salini profondi presenti nell'Adriatico Centrale. La loro distribuzione mostra una stretta relazione tra i loro reciproci sviluppi.
The Western Mediterranean Sea is a natural laboratory to address questions about the formation an... more The Western Mediterranean Sea is a natural laboratory to address questions about the formation and evolution of continental margins and the relationship between surface and deep processes. The evaporites deposited during the late Miocene's Messinian Salinity Crisis (MSC) strongly impact its sedimentological and geomorphological evolution. Hereafter, we present a compilation of some of the main regional seismic stratigraphic markers throughout the Western Mediterranean Sea. We provide in xyz format (z in second twt) the original, not interpolated, points interpretation of the following horizons: i) Acoustic basement, ii) Base and Top of the MSC salt, also known as Mobile Unit (MU), iii) base Pliocene and iv) Seafloor. The available reflection seismic dataset, coming from a collaboration between French, Spanish, Algerian and Italian research institutes, covers most of the Western Mediterranean sub-basins with the exception of the Ligurian Basin. This compilation is currently the m...
The Adriatic Sea hosts important historically explored hydrocarbon provinces. In the northern are... more The Adriatic Sea hosts important historically explored hydrocarbon provinces. In the northern areas, the main sources of hydrocarbon productivity are from biogenic gas reservoirs located in Quaternary thick deltaic depositional systems related to the Apennine and Dinaric foreland domain. In addition, Mesozoic thermogenic oil plays were identified and exploited in the Southern areas. Herein, we use basin and petroleum systems modelling (BPSM) techniques to investigate the still unproved thermogenic hydrocarbon potential of deep Mesozoic basins in the North Adriatic Sea and to correlate the results with the sedimentary evolution of proven petroleum systems in the Central and South Adriatic, both in the Italian and Croatian offshore areas. We used the regional CROP-M16 marine seismic profile in the eastern segment of the study area, where it cuts the western margin of the Dinaric carbonate platform and reaches the pelagic domain of the Umbria-Marche basin intersecting the Barbara isolated platform (Figure 1). We reprocessed the 2D seismic data set to obtain the correct dips and depths of the geological structures from a depth-migrated profile. During the interpretation phase, we integrated the information from profile CROP-M16 with the orthogonal CROP-M17B and C profiles that are intersecting the Alessandra-001 exploration well. The interpretation allowed a detailed analysis of the main lithological discontinuities and of the fault system. We used the interpreted features together with the petrophysical parameters inferred by the available wells in the area and by literature, for 2D petroleum systems modelling. Our simulation integrated the available information to produce a set of possible scenarios of basin development, with the objective to understand the maturation and migration of hydrocarbons.
The geological genesis, evolution and depositional settings of the Mediterranean Sea have been st... more The geological genesis, evolution and depositional settings of the Mediterranean Sea have been studied for decades by the scientific community which, for some aspects, combines research with the Petroleum Industry to enhance hydrocarbon exploration. It is in these circumstances that the geophysical study hereafter described was conceived. Two research bodies and a multi-client geophysical company have been involved in this project: the Department of Mathematics and Geosciences of the University of Trieste (DMG), the Italian National Institute of Oceanography and Experimental Geophysics (OGS) and TGS Geophysical Company ASA. The paper presents a geophysical analysis, based on interpretation of ten 2D multichannel seismic reflection profiles located in the Eastern Sardo-Proven\ue7al basin of the North-Western Mediterranean crossing domains from the outer West Sardinian shelf to the deep basin (Fig.1A,B). The post-stack time migrated lines have a total length of 1545 km and cover an area of about 35.000 km2. The profiles belong to three distinct datasets (WMR, WS, CROP, location on Fig.1A) recorded by different geophysical projects, each of them using specific acquisition parameters. The five WMR (West Mediterranean Regional) profiles were provided by TGS. The three WS (West Sardinia) profiles were acquired by their owner OGS. The two CROP (CROsta Profonda) lines, provided by the DMG, were originally sponsored by AGIP-ENI, CNR & ENEL. The presence of the Messinian rock salt, that within a sedimentary sequence produces halokinesis and scatters most of the acoustic energy, suggested the reprocessing in time domain of a part of a CROP seismic profile in order to improve the imaging of those reflections that are strongly deformed or masked. To enhance image accuracy assessing size and location of geological structures beneath the Messinian salt, a pre-stack depth migration (PSDM) was executed using the Kirchhoff algorithm. The processing outcomes were useful not only to enhance and better define the entire seismic interpretation on the available datasets, but also allowed the evaluation of the peculiar lithologic/stratigraphic conditions of the basin. The integration of the three datasets gave better coverage of the study area and supplied complementary information thanks to different resolutions. On the whole, the work presented hereafter aimed at better knowledge of the depositional history, starting from the Messinian Age, of the North-Western Mediterranean basin
The Adriatic basin represents one of several restricted basins located in the Mediterranean Area.... more The Adriatic basin represents one of several restricted basins located in the Mediterranean Area. It consists of the foreland of three different orogenic belts: the Dinarides to the East, active during the Eocene, the Southern Alps to the North, active since the Cretaceous time, and the Apennines to the West, active since the Paleogene. The Apennines had a primary role during the Messinian Salinity Crisis (MSC), conditioning the connection between the Adriatic basin, the Ionian basin, and the proto-Tyrrhenian basin. During the Messinian, the present Adriatic Sea was characterized by shallow water domains, where gypsum evaporites initially deposited and often successively incised or outcropped.
COST-ANR MEDSALT Symposium, 24-28 October 2016, Palermo, Italy.-- 1 pageThis study is based on mu... more COST-ANR MEDSALT Symposium, 24-28 October 2016, Palermo, Italy.-- 1 pageThis study is based on multibeam bathymetry and multi-channel seismic reflection data collected during Eurofleets R/V OGS Explora, Cruise No. E12 (SALTFLU), Valencia (Spain) 22/06 - 04/07/2012. Modelling of overpressure evoltion is based on the resulting stratigraphy. The study area encompasses proposed drill sites BAL-02 and BAL-02 of IODP pre-proposal 857B-Pre, Deep-Sea Records of the Messinian Salinity Crisis (DREAM), proposed by J. Lofi et al in 2015. We identify four types of salt-induced abyssal plain sediment deformation structures: (1) a belt of elongated abyssal plain seahills thought to be the attenuated surface expression of salt rollers either produced by reactivated right strike slip faults synthetic to the master fault of the EBE or by differential compaction above such faults; (2) anastomosing knolls in the Menorca Fan area thought to be the product of subsurface salt deformation and gliding triggered by differential sedimentary load; (3) abyssal knolls and seahills spread in the entire abyssal plain across the basin thought to be the product of subsurface salt anticlines and pillows in a relatively more evolved stage of basin evolution affected by basement faulting, perhaps northward propagation of the shortening affecting the Algerian margin; and (4) a small flat topped circular mound in the middle of the abyssal plain interpreted as a mud volcano extruding sediments and fluids of likely pre-Messinian origin. The structures suggest that the crustal transition, not imaged in the seismic data due to intense deformation does not correspond to the Emile Baudot Escarpment (the present day continental tectonically driven continental slope). Rather it is located farther offshore in the deep basin, approximately where intense halokinesis occurs in the abyssal plain, marking the edge of the deep Messinian basin filled with kilometer-thick evaporites. Messinian marginal basins, therefore, are presently located also below the abyssal plain, at the floor of the Emile Baudot Esacarpment. Evidence for sub-salt overpressure is provided by pearchment structures in the deep Messinian basin. A compaction disequilibrium modeling exercise demonstrates that the high sedimentation rate of the thick evaporitic succession in the deep Messinian basin, may indeed generate considerable overpressure, persisting today (overpressure coefficient up to 0.8). However, the reduced evaporite thickness in the marginal basins reduces considerably the likelihood of sub-salt overpressure (overpressure coefficient up to 0.2). Therefore, we conclude that marginal basins belong to different geological domains compared to the deep basin, being the difference given by different crustal structure, evaporite thickness, in some cases evaporite composition (absence of halite layer), and pore pressure regime below and within the evaporitic formations. An upward pore water expulsion system is inferred through the Plio-Quaternary sedimentary cover induced by gypsum dehydration to anhydritePeer Reviewe
Since the discovery of widespread Salt and Gypsum deposits of the Mediterranean Sea in the early ... more Since the discovery of widespread Salt and Gypsum deposits of the Mediterranean Sea in the early '50s, a large number of scientists tried to unravel the mystery related to this huge deposition of evaporites. Evidence of the later so-called "Messinian Salinity Crisis" (MSC) are largely distributed all around the Mediterranean Basin and widely studied. Although gypsum deposits were recognized in some peripheral or marginal basins (e.g. Sorbas Basin in Spain, Northern Apennines in Italy), mechanism of their deposition and formation are still uncertain. Particularly, the so-called Gessoso-Solfifera formation (GS Fm) was recognized in the '50s by Selli in several outcrops in Northern Apennines and it is nowadays well known and mapped in the onshore outcrops. A regional analysis in the Adriatic Sea is still incomplete, even though a large amount of data is available (2D multichannel seismic lines, boreholes, exploration reports). In the Adriatic Sea, the MSC event can be recognized in the 2D seismic lines as actual thin deposit (maximum GS Fm thickness of about 120 ms TWT) or Messinian erosional surface (MES). In both cases, a strong and clear reflector at the Pliocene base is picked and calibrated by the boreholes reaching its depth. Along the main part of the available seismic profiles it is sometimes very hard to ascribe this strong reflector to the MES or to the presence of a thin gypsum layer. Calibration of 2D seismic lines with boreholes, also integrated by physical properties derived from geophysical well logs and core data) of the Plio-Quaternary sediments, allowed a detailed seismic facies analysis useful for this purpose. A structural map of the Plio-Quaternary base describes the Plio-Quaternary deformation that affected the study area mainly as Apennine foreland. The thickness map of the GS Fm describes the subsidence and the erosional effect occurred during the MSC. Both these maps are here presented as a first result of a regional study, that intends cover the whole Adria offshore.
The Messinian Salinity Crisis (MSC), which widely affected the whole Mediterranean basin, induced... more The Messinian Salinity Crisis (MSC), which widely affected the whole Mediterranean basin, induced rapid and spectacular palaeoenvironmental changes. It led to a major erosion of the onshore areas and the upper parts of the continental shelves and slopes, as well as important evaporitic deposits in the offshore deep basins. The Corsica Basin belongs to the so-called "intermediate-depth basin" type because of its location between the coastal plainshelf area of East Corsica and deeper marine basins in the northern Tyrrhenian Sea. The MSC event took place in the Corsica Basin during a period of active regional tectonics, contemporaneous with the opening of the Tyrrhenian Sea, as well as during the development of the Corsica Basin and the Elba-Pianosa Ridge. Based on the interpretation of high-resolution seismic reflection profiles and a new 1:250,000 scale synthetic geological map, we establish that the MSC is recorded in the Corsica Basin through the occurrence of two sedimentary formations bounded by three remarkable surfaces. These seismic markers suggest local and temporal variations in relative water level and associated depositional environments that differ between the north and south of the Corsica Basin. During the MSC, the northern sector (Golo Basin) was emerged, whereas the southern sector (Orbo Basin) was often flooded or submerged. In the Orbo Basin, the deposits record both an episode of intra-MSC climate change and regional tectonic events. During the MSC, the Corsica Basin was a perched lake, isolated from the deeper Tyrrhenian basins. The connection with the Tyrrhenian basins was re-established during the final stages of the MSC, before the catastrophic Pliocene reflooding, initiated by retrogressive Thinon et al. In press 2016-Seismic markers of the Messinian Salinity Crisis in an intermediate-depth basin: data for understanding the Neogene evolution of the Corsica Basin (Northern Tyrrhenian Sea)-Marine and Petroleum Geology 2 erosion during a relative lowstand. An extensive network of incised valleys was thus established in the Orbo basin, allowing the drainage of the Corsica Basin southwards into the deeper Tyrrhenian basins. These markers record the active regional tectonic context throughout the MSC. The Orbo basin was strongly subsident along its western rim, while its eastern rim was uplifted. In turn, the Golo basin subsided from middle Pliocene times onwards, while the northern, eastern and southern edges of the Corsica Basin were deformed and uplifted.
Introduction. We present a comparison between two multichannel seismic datasets acquired across t... more Introduction. We present a comparison between two multichannel seismic datasets acquired across the passive margins of the west Mediterranean sea: the west Sardinia continental margin extending in the east Sardo-Provençal basin and the South Balearic continental margin extending in the northwestern Algero-Balearic basin. The two margins bear in common the origin from continental rifting, but underwent different geodynamic histories and are not coeval. The Sardo-Provençal basin opened following the Oligocene-Early Miocene breakup of the European plate and anticlockwise rotation of the Sardinian block. According to Mauffret et al. (2004) this phase ended in the early Miocene (16 Ma), when the opening of the Algero-Balearic basin started to open as a result of rifting between the Balearic Promontory and the African margin until the Tortonian (8 Ma). The Messinian Salinity Crisis (MSC) affected the whole Mediterranean basin, with deposition of evaporitic sequences in the deep basins, lower continental slopes, and in several shallower marginal basins; usually, in the continental margins, the MSC originated noticeable erosional truncations that locally cause important hiatuses in the pre-Messinian sedimentary sequences, covered by the Plio-Quaternary sequence.
Uploads
Papers by Anna Del Ben