3-D stratigraphic architecture, sedimentary processes and controlling factors of Cretaceous deep-water resedimented carbonates (Gargano Peninsula, SE Italy)

摘要

Detailed geological mapping in 3-D supported by a LIDAR-derived DOM, sedimentologic and biostratigraphic analyses and 3-D numerical modelling are used to characterise the stratigraphic architecture of deep-water resedimented carbonate systems in the Gargano Peninsula (SE Italy). The base-of-slope succession spanning the upper Aptian to Danian p.p. was subdivided in five lithostratigraphic units that record the complex evolution and sedimentary dynamic along a segment of the Apulian Platform margin that was strongly influenced by syn-sedimentary tectonic activity. The characteristic location in a relay zone between the NW-SE trending platform margin and the E-W oriented Mattinata Fault System favoured the existence of a transtentional zone from the upper Aptian up to the end of the Cretaceous. The spatial distribution of the gravity flow deposits, the stratal geometries, the lateral facies changes, and the biostratigraphic data demonstrate that the base-of-slope systems were sourced by distinct platform blocks characterised by different slope profiles (abrupt to west and distally steepened to the north). In this context, the nature and origin of the resedimented carbonate material were controlled by the fracturation of the margin, the response of the carbonate factory to relative sea level changes but were also strongly influenced by the slope profile. This study demonstrates the relevance of combining traditional field work with numerical tools to improve the understanding of ancient sedimentary systems, notably by mapping the stratal architecture and lithologies in continuity and at various scales (on DOMs), and by reconstructing the paleo-topographies in 3-D.