Carlo Nicolai

The structural deformation and the petroleum system of the southern Apennines thrust belt (SATB) are studied along a regional cross section traversing the Monte Alpi–Tempa Rossa fields. The SATB is interpreted as a system of three major structural blocks incorporating the basement and the sediments up to the Apulian platform deposits beneath an allochthonous complex. The Thrustpack software has been used to reconstruct the successive geometries and their progressive burial under foredeep sediments and the allochthonous complex. The bottom of the Apulian platform and the basement are involved in the deformation, and the thickness of the Permian interval, drilled in the foreland, is extended regionally. The timing of the deformation is constrained by the ages of the Pliocene foredeep sediments drilled on top of the Apulian platform. This record was also instrumental to propose a flexure scenario of the migrating foredeep-forebulge system, in which the slope of the topography had to be...

ABSTRACT In this paper, the depth map of the top carbonate sequence top in the Southern Apennines-Southern Adriatic region is presented, based on approximately 22,000 Km of seismic lines and more than 300 wells. The Top Adria Carbonate (TAC) is seismically characterised by a high amplitude low frequency reflection, resulting from the change in acoustic impedance between the siliciclastic sediments and the underlying carbonate succession. It is not an isochronous event and geologically it does not correspond to a specific palaeogeographic unit. The TAC map may represent either the top of the carbonate pelagic sequence (Cretaceous-Eocene) in the basinal area, the top of shallow water (Cretaceous-Messinian) in the platform region and the by-pass zone in the slope areas. It covers the Italian sector of the Apulian Platform, the southernmost part of the Central Adriatic Basin and the western sector of the Southern Adriatic basin. The structural setting of the thrustbelt, foredeep and foreland areas are depicted. The thrustbelt system appears non-cylindrical; in fact it is segmented in at least three different arcs. The frontal thrust of each of these arcs is East-West oriented in the northern segment and turns North-South moving to the East and to the South. The horizontal displacement along these main thrusts and the number of related structural trends is not constant. In a few instances, a single thrust zone generates a major antiformal stack, which accommodates most of the shortening. In other areas the same shortening is accommodated through a number of separated thrust sheets forming individual structural trends. The southernmost sector of the Southern Apennine has a poorly defined palaeogeography. The TAC seismic reflector is continuous from the thrust belt to the foreland area. However, the westernmost part of the map (based on seismic and wells data) represents the architecture of a different palaeogeographic unit (Apenninic Platform). The apparent lateral continuity between these two units can be explained either by the complete underthrusting of the Lagonegro Basin beneath the Apenninic Platform or the absence of this basin between the two platforms. The off-shore extension of the Mattinata strike slip fault is the most prominent element of the eastern sector of the foreland. It branches into two arms in the easternmost area. Some of the structures in this area (e.g. Gondola High) are related to the activity of this fault. However the detachment folds located east of the Gargano promontory are only partially affected by it. Their formation appears to have been facilitated by thick Triassic evaporites (Grifone 1 well). The TAC Map also defines the shape of the Apulian Platform margin in the northern and eastern sector and provides the geometry of the Rosaria Mare Upper Cretaceous intra-platform basin.

The Southern Apenmines Thrust Belt (SATB) is a prolific petroleum province in Italy. In this work, we reconstruct its structural evolution since the Messinian and the timing of hydrocarbon generation and expulsion, integrating geological and geochemical constraints.

ABSTRACT An updated review of the Southern Apennines structural architecture, a proven petroleum province in Italy, is presented taking into consideration the new stratigraphic and structural constraints provided both by almost forty years of petroleum exploration and by the recently reprocessed CROP-04 deep seismic reflection profile. A regional geological cross-section, drawn nearly parallel to the CROP- 04 seismic line, is described and discussed to point out the main features of the Southern Apennines. Moreover, a second shorter crosssection (named M. Foi cross-section), very well constrained by good quality seismic and well data, is used to describe the allochthonous units structural setting in detail, with special attention to the tectonic evolution of the Lagonegro units. The Southern Apennines (SA) are a Neogene and Quaternary thrust belt located in the hanging wall of a W-directed, E-retreating, subduction of the Apulo-Adriatic lithosphere. From a structural point of view, the SA are made up of a huge duplex system consisting of two main units: the allochthonous nappes and the Apulian platform. The allochthonous units, derived from the deformation of both peritidal carbonate platforms and pelagic basin successions and from the stratigraphically overlying foredeep deposits, are completely detached from their original substratum and transported onto the carbonates of the Apulian platform. Beneath the mountain chain the Apulian carbonates are deformed to form a buried antiformal stack. Some outstanding problems concern both the structural setting of the deeper part of the SA thrust belt (e.g. the degree of involvement of the crystalline basement in the Apulian antiformal stack) and of the allochthonous nappes. CROP-04 and well data suggest the possibility that Lagonegro and Apulian Platform carbonate units could extend at depth westward below the Apenninic platform units. Moreover, some geological and geophysical evidences suggest that shortening within the Apulian carbonate platform units might be significantly greater than previously assumed in several recent structural interpretations. The increased shortening hypothesis may have relevant implications for a better understanding of the petroleum system evolution. The complex antiformal stack-type structure of the Lagonegro units, revealed by well data and characterised by the tectonic repetition of the couple «Scisti Silicei» plus «Calcari con Selce», could be reproduced with a relatively simple series of ramp-flat thrusts propagating through the Lagonegro succession. Based on both the regional and the M. Foi cross-sections, a likely original width of about 125 km has been estimated for the Lagonegro basinal domain: 90 km are now deformed in antiformal-stack type structures in the axial zone of the Campania-Lucania arc while other 35 km might be buried, in our interpretation, below the Apennine units. The resulting total internal shortening for the Lagonegro domain is about 60%.

ABSTRACT Summary In this paper we present the review of the Italian Dil Plays and an evaluation of the Yet To Find (YTF). The YTF has been calculated adding logether the mean risked reserves of Prospects, Leads and Notional Leads. The YTF is estimated al 3760 MMbóls of oil subdivided in Smajor sub-basins (Tab I). These subbasins are defined on the basis of the geography and on the existence of one or more plays. A ranking of the different sub-basins is also provided.

In this paper, the depth map of the top carbonate sequence top in the Southern Apennines-Southern Adriatic region is presented, based on approximately 22,000 Km of seismic lines and more than 300 wells. The Top Adria Carbonate (TAC) is seismically characterised by a high amplitude low frequency reflection, resulting from the change in acoustic impedance between the siliciclastic sediments and the underlying carbonate succession. It is not an isochronous event and geologically it does not correspond to a specific palaeogeographic unit. The TAC map may represent either the top of the carbonate pelagic sequence (Cretaceous-Eocene) in the basinal area, the top of shallow water (Cretaceous-Messinian) in the platform region and the by-pass zone in the slope areas. It covers the Italian sector of the Apulian Platform, the southernmost part of the Central Adriatic Basin and the western sector of the Southern Adriatic basin. The structural setting of the thrustbelt, foredeep and foreland areas are depicted. The thrustbelt system appears non-cylindrical; in fact it is segmented in at least three different arcs. The frontal thrust of each of these arcs is East-West oriented in the northern segment and turns North-South moving to the East and to the South. The horizontal displacement along these main thrusts and the number of related structural trends is not constant. In a few instances, a single thrust zone generates a major antiformal stack, which accommodates most of the shortening. In other areas the same shortening is accommodated through a number of separated thrust sheets forming individual structural trends. The southernmost sector of the Southern Apennine has a poorly defined palaeogeography. The TAC seismic reflector is continuous from the thrust belt to the foreland area. However, the westernmost part of the map (based on seismic and wells data) represents the architecture of a different palaeogeographic unit (Apenninic Platform). The apparent lateral continuity between these two units can be explained either by the complete underthrusting of the Lagonegro Basin beneath the Apenninic Platform or the absence of this basin between the two platforms. The off-shore extension of the Mattinata strike slip fault is the most prominent element of the eastern sector of the foreland. It branches into two arms in the easternmost area. Some of the structures in this area (e.g. Gondola High) are related to the activity of this fault. However the detachment folds located east of the Gargano promontory are only partially affected by it. Their formation appears to have been facilitated by thick Triassic evaporites (Grifone 1 well). The TAC Map also defines the shape of the Apulian Platform margin in the northern and eastern sector and provides the geometry of the Rosaria Mare Upper Cretaceous intra-platform basin.