The Barremian-Aptian shallow-marine carbonates of Monte Faito and of Santa Maria bore cores (central-southern Apennines, Italy). Regional correlation based on cyclostratigraphy

Amodio S. (*), Ferreri V. (**) & D'Argenio B. (**)
(*) Dipartimento di Scienze per l'Ambiente, Università degli Studi di Napoli "Parthenope", Centro Direzionale, Isola C4, 80143 Napoli. E-mail: sabrina.amodio@uniparthenope.it (**) Istituto per l'Ambiente Marino Costiero, CNR, Calata Porta di Massa, Porto di Napoli, 80142 Napoli.

In the last twenty years, high-resolution (cm scale) studies of several Cretaceous carbonate platform successions in centralsouthern Italy have demonstrated that they carry clear evidence of astronomically controlled eustatic oscillations refl ected on their hierarchical stacking patterns (elementary cycles, bundles and superbundles) and exhibit a sequence-stratigraphic configuration, that is well evident in their superbundles (long eccentricity cycles) as well as in the composite mode of their aggradational pattern, laterally consistent also at more than 100 km distance. Here are presented the centimetre-scale facies analysis of the S. Maria 6 and 4 Agip bore cores (east of Maiella Mountain, Abruzzi region, Early Barremian- Late Aptian in age) and of the Monte Faito section (Monti Lattari, Campania Region, Barremian – Early Aptian in age). Taking into account the cyclic stacking patterns of the lithofacies and their grouping as well as of the early diagenetic features, the environmental oscillations have been constrained in well defi ned time intervals, typical of the Milankovitch periodicities (from ≈ 20 to ≈ 400ky). Based on cyclostratigraphy and sequence stratigraphy criteria and using appropriate biostratigraphic, isotopic and paleomagnetic markers, high-resolution physical correlations (precision 100 ky) have been traced at regional scale among S. Maria composite core, Monte Faito and the previous studied Monte Raggeto (Monte Maggiore) sections. A chronostratigraphic diagram has been assembled for each of the above sections showing that bundles may be locally missing. Moreover, a Barremian-Aptian composite orbital chronostratigraphy has been assembled suggesting the minimum time duration recorded in the considered interval, so that a regional sea-level oscillations history may be restored with a precision of ≤400 ky. On these bases, a minimum duration of 5.2 my for the Barremian interval (13 superbundles) has been estimated, close to the 5 my calculated for the whole Barremian from OGG et alii (2008). These results show as cyclostratigraphy of carbonate platform sequences, integrated with other stratigraphic methodologies and high-precision long distance correlations, is a valid tool to estimate the time duration of stratigraphic intervals and to assemble a "floating" orbital time scale.

shallow-marine carbonates, environmental evolution, orbital cyclicity, regional correlation, Barremian-Aptian chronostratigraphy, central-southern Italy