Distinguishing tectonically-and gravity-driven synsedimentary deformation structures along the Apulian platform margin (Gargano Promontory, southern Italy)

Abstract

The assessment of deformation types within the slope of a carbonate platform can be complicated by the\ud possible interaction of rooted (tectonically-induced) and superficial (gravity-driven) structures. An ideal\ud case study to document and distinguish tectonically- and gravity-driven structures is provided by the\ud Cretaceous slope-to-basin carbonates exposed in the Gargano Promontory, southern Italy. These carbonates\ud formed adjacent to the Apulian platform margin, which was oriented approximately NEeSW to\ud NWeSE along the southern and northern edges of the promontory, respectively. Slump-related folds are\ud characterised by axial planes typically oriented either sub-parallel or at small angles to the strike of the\ud inferred paleoslope. In fact, the strike of folds is roughly NEeSW in the southern portion of the study\ud area, whereas it is NWeSE in the northern part. Correspondingly, gravity-driven normal and reverse\ud faults strike sub-parallel and at acute angles to the adjacent Apulian paleoslope. Cretaceous tectonic\ud faults in the slope-to-basin carbonates form two principal sets striking NWeSE and WNW-ESE. The\ud former set is made up of normal faults and the latter one includes mainly oblique-slip normal faults.\ud Neither normal nor oblique-slip normal faults show any relationship with the geometry of the paleoslope.\ud The results obtained from this study may help the interpretation of subsurface data in those\ud geological contexts in which the interplay of gravitational and tectonic processes is responsible for\ud deformation

Fault‐controlled dolomite bodies as palaeotectonic indicators and geofluid reservoirs: New insights from Gargano Promontory outcrops

“…Sub‐kilometre Cretaceous syn‐sedimentary faults which are similar in orientation to those of the dolomite bodies were documented by Korneva et al . () within limestones of the Casa Varfone and Maiolica formations. These faults are commonly simple discontinuities, quite straight and understepping (although connected faults are documented as well), with no or poorly developed damage zones.…”

“…The faults that drove the dolomitization have trends and kinematics similar to those of the Early Cretaceous syn‐sedimentary tectonic faults reported in Gargano Promontory by Korneva et al . (), and near Murge by Festa () and Korneva et al . ().…”

“…); and (ii) the Cretaceous faults, especially the tectonic ones, documented in Gargano Promontory by Korneva et al . ().…”

“…(A) Structural geological sketch map of Southern Apennines (modified after Patacca & Scandone, ; Vezzani et al ., ). (B) Geological sketch map of the eastern part of Gargano Promontory, illustrating dolomite distribution within the Casa Varfone and Maiolica formations (modified after Martinis & Pavan, ; Korneva et al ., ). Probable palaeo‐faults that controlled dolomitization are those inferable from mappable dolomite bodies forming elongated ridges atop topographic highs.…”

“…Nevertheless, a recent work by Korneva et al . () interprets some of these faults as Cretaceous in age and divides them into two categories: tectonic or gravity‐driven. The tectonic faults oriented east–west to WNW–ESE are strike‐slip to transtensional, whereas normal faults strike north‐west/south‐east.…”