The Southern Apennine Thrust Belt - Forward Structural and Geochemical Modelling Since Messinian Times

Abstract

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. The main exploration target in SATB is the Cretaceous part of the carbonate Apulian Platform that forens the deepest structures of the SATB below the outcropping Meso-cenozoic Allochthonous Complex. Forward structural modeping and thermal modeping have been performed along an almost 130 km long regional line, that crosses the Val d'Agri, where major oil discoveries are located. This forward modelleng was performed with the Thrustpack code (Sassi & Rudkiewicz, 2000). Present-day geometry has been reconstructed integrating seismic, wens and surface data. A structural-setting involving the bottom of Apulian Platform and lts base (Perenlam plus Basement) by means of thrusts faults deep-rooted withen the crost is presented. . In order to investigate the petroleum system evolution, the timing of deformation has been defined integrating subsurface and surface data. The migrating foredeep-forebulge system of the SATB was reconstructed using geometrical, geochemical and thermal constraints. Then, the conductive thermal regime has been calibrated upon present-day temperatures and vitrinite reflectance, leading to the hydrocarbon generation and expulsion history from the source rock withen the Apulian Platform. Implication for structural interpretation and Petroleum exploration are discussed .

The Pliocene‐Quaternary wedge‐top basins of southern Italy: an expression of propagating lateral slab tear beneath the Apennines

“…Irrespective of the different tectonic interpretations, variable reconstructed amounts of shortening, etc., there is a general consensus that the Pliocene to Early Pleistocene tectonic evolution of the shallow allochthonous wedge was essentially controlled by deep‐seated processes occurring in the underlying Apulian Platform carbonates (e.g. Mazzoli et al ., ; Menardi Noguera & Rea, ; Butler et al ., ; Sciamanna et al ., ; Shiner et al ., ; Scrocca et al ., , ; Patacca & Scandone, ). In particular, the development and evolution of Pliocene‐Pleistocene wedge‐top basins have been tightly related with the growth of inverse fault‐related, long‐wavelength folds in the buried Apulian Platform carbonates (Hippolyte et al ., ).…”

“…Thin‐skinned thrusting and associated large amounts of horizontal shortening have been proposed for the subsurface Apulian Platform carbonates in both the central (e.g. Patacca et al ., ; Di Luzio et al ., ) and the southern Apennines (Sciamanna et al ., ; Scrocca et al ., , ; Patacca & Scandone, ). However, recent geophysical studies have provided evidence that deep‐seated reverse faulting involves the basement (Speranza & Chiappini, ; Improta & Corciulo, ; Steckler et al ., ), and interpretation of high‐quality seismic profiles, cross section balancing and restoration of the buried Apulian Platform carbonates favour an inversion tectonics model involving reactivation of pre‐existing (Permo‐Triassic) basement normal faults (Shiner et al ., ).…”

Deep structure of the southern Apennines, Italy: Thin‐skinned or thick‐skinned?

“…1. The first (Figure 1a) suggests the existence of a basement wedge (the classic backstop proposed for most of the Alpine and Cordillera types of orogen) developed during the formation of the SA [e.g., Casero et al , 1988; Roure et al , 1991; Mazzoli et al , 2000; Menardi Noguera and Rea , 2000; Sciamanna et al , 2000; Speranza and Chiappini , 2002].…”

“…These models (Figures 1a and 1b) produce significantly different estimates of the shortening suffered by the Apulian carbonate platform and, consequently, of its original length. This, in turn, has relevant implications both for any attempt to reconstruct the Mesozoic paleogeography in this area [e.g., Patacca and Scandone , 1989; Dercourt et al , 1992; Catalano et al , 2001] and also for a better understanding of the petroleum system evolution [e.g., Roure and Sassi , 1995; Sciamanna et al , 2000].…”

Compositional grading in the oil column: advances from a mass balance and quantitative molecular analysis

“…The primary hydrocarbon charge event is modelled to occur in the Pliocene and includes a late influx of light hydrocarbons. Results from tectonic modelling (Sciamanna et al 2000) indicate that the reservoir interval experienced a post-charge physical uplift of 2000 m over a timespan of 2 Ma that is responsible for reservoir pressure reduction on the order of 6000 psi and a concomitant temperature decrease of 50~…”