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In the southern Apennines fold-and-thrust belt, thermal indicators record exhumation of sedimentary units from depths locally in excess of 5 km. The thrust belt is made of allochthonous sedimentary units that overlie a 6-8-km-thick, carbonate footwall succession. The latter, continuous with the foreland Apulian Platform, is deformed by reverse faults involving the underlying basement. Therefore, a switch from thin-skinned to thick-skinned thrusting occurred as the Apulian Platform carbonates-and the underlying thick continental lithosphere-were deformed during the latest shortening stages. Apatite fi ssion track data, showing cooling ages ranging between 9.2 ± 1.0 and 1.5 ± 0.8 Ma, indicate that exhumation marks these late tectonic stages, probably initiating with the buttressing of the allochthonous wedge against the western margin of the Apulian Platform. Pliocene-Pleistocene foreland advancing of the allochthonous units exceeds the total amount of slip that, based on cross-section balancing and restoration, could be transferred to the base of the allochthon from the underlying thick-skinned structures. This suggests that emplacement of the allochthon above the western portion of the Apulian Platform carbonates was followed by gravitational readjustments within the allochthonous wedge, coeval-and partly associated with-thick-skinned shortening at depth. The related denudation processes are interpreted to have played a primary role in tectonic exhumation.

An automatic approach for analyses of Raman spectra of dispersed organic matter in diagenesis is proposed in this work. The need for a reproducible method of thermal maturity assessment by means of Raman spectroscopic analyses on the organic matter is essential for the development of this technique as a robust support in organic petrographical analyses. The new method was tested on concentrated kerogen derived from a set of 33 samples that originated from cuttings from a 5000 m-thick section drilled in offshore Angola. The proposed method can be applied separately in the D and G bands regions of the Raman spectra, and uses a fitting approach based on asymmetrical Gaussian deconvolution and on the measurement of the integrated area. Results from this work demonstrate that Raman parameters carried out by the new methods reflect the increase in aromaticity in kerogen in diagenesis. Finally, two parametric equations have been proposed to correlate Raman parameters and thermal maturity: the first is for the thermal maturity interval between 0.3 and 1.5% Ro; and the second has a higher precision of between 1.0 and 1.5% Ro. The two equations are the result of a multi-linear regression based on robust correlations between Raman parameters and vitrinite reflectance (Ro%).

The inception and growth of the active Carpino-Le Piane Basin Fault System (CLPBFS; central-southern Apennines, Italy) was analysed with respect to the neighbouring Isernia and Surrounding (ISFS) and Boiano Basin (BBFS) extensional Fault Systems. 39 Ar-40 Ar dating showed that the BBFS was already active 649 ± 21 ka BP and that the ISFS was active at least 476 ± 10 ka BP, whereas the activity of the CLPBFS started certainly later than 253 ± 22 ka BP, and very probably as recently as <28 ka BP. These ages, combined with structural data (geometry and kinematics of the fault systems), indicate that the inception and development of the CLPBFS could be strictly related to the stress changes caused by earthquakes occurring on the BBFS.

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MonteAlpi represents the only area of the southern Apennines where Apulian carbonates, elsewhere buried beneath a several-km thick allochthon, are exposed at the surface. These rocks also represent the reservoir interval in southern Italy’s major oil fields. The tectonic evolution of this substantially exhumed area of the fold-and-thrust belt, derived from conventional structural and stratigraphic considerations via integration into the regional framework, has been tested and detailed by the analysis of vitrinite reflectance, clay mineralogy, apatite fission track, and fluid inclusion data. The Apulian carbonates of Monte Alpi underwent significant tectonic burial as a result of thin-skinned thrusting in early Pliocene times. Simplified burial and thermal modeling suggests that the thickness of allochthonous material emplaced on top of Monte Alpi was probably in excess of 5 km. Exhumation is envisaged to have started in the late Pliocene, when the area emerged and the tectonic load started to be eroded off Monte Alpi. A significant stage of exhumation is inferred to have taken place in uppermost Pliocene-early Pleistocene times as a result of thick-skinned reverse faulting at depth and coeval thin-skinned extension within the overlying allochthon. After shortening ceased throughout the whole southern Apennines, middle Pleistocene-Holocene tectonic exhumation of Monte Alpi was essentially controlled by thick-skinned extensional tectonics. This process is still active and controls the present-day seismicity of the study area

Abstract. The geological structure of the Central Apennines along a section line across the Lazio-Abruzzi carbonate platform has traditionally been interpreted using a thin-skinned thrust tectonic model, in which the sedimentary cover has been detached from an undeformed basement below. Such models have been used to predict that very large amounts of crustal shortening (e.g. 172 km over a section 173 km long) have occurred. Alternatively, in this paper we reinterpret the surface geology and well data along the same section line using a thick-skinned thrust tectonic model. Restoration of this section shows that the amount of shortening (37 km over a section 158 km long) is considerably lower than previously predicted; this is accomplished by open buckling of the carbonate platform, tighter folding of the basin scarp stratigraphy, and reactivation of pre-existing extensional faults. Age bracketing on thrust fault movement allows shortening rates for the two different models to be calculated; these are < 6 mm yr −1 for the new interpretation, but over 24 mm yr −1 for the equivalent thin-skinned model. This latter value is significantly greater than shortening rates reported for most other thrust belts, suggesting that thick-skinned tectonics is a more satisfactory explanation for the structure of this area. The two most important implications of this are that subthrust hydrocarbon plays are largely absent in the area, and Neogene contractional deformation in this part of the Apennines resulted in much less crustal shortening than previously predicted.