The impact of tectonic activity on carbonate density-flow deposition along two sectors of the Apulia Carbonate Platform
Author:
Saelen Gunnar1, Spalluto Luigi2, Grunnaleite Ivar3, Sande Atle Jørgen Hestad1, Jensen Niels Bo1, Svendsen Per Olav Eide1, Osso Gaetano4, Paoli Nicola4, Talbot Michael R.1
Affiliation:
1. 1 Department of Earth Science, University of Bergen, Allégtaten 41, N-5007 Bergen, Norway 2. 2 Dipartimento di Scienze della Terra e Geoambientali, Univeristà degli Studi di Bari “Aldo Moro,” via E. Orabona, 4, I-70125, Bari, Italy 3. 3 Tectonor, c/o IPark, P.O. Box 8034, N-4068 Stavanger, Norway 4. 4 Studi & Ricerche Geologiche, Via Orti no. 21, 87032 Amantea (Cs), Italy
Abstract
ABSTRACTGeneration of thick megabreccias along carbonate platforms apparently relies on the establishment of overpressured zones in the margin and upper slope deposits (particularly during relative sea-level lowstands), but the main triggering mechanism is thought to be seismic tremors. Here, we present a detailed sedimentological analysis of carbonate density-flow deposits south and north of the Mattinata Fault, a major strike-slip fault zone in the Gargano Promontory (Italy). The analysis shows that in the southern sector the deposits of Albian–Cenomanian age (Monte S. Angelo Formation) are made up predominantly of thick and amalgamated debrites (megabreccias), whereas some 25 km to the north they are composed predominantly of prograding high-density turbidites. Moreover, detailed analysis of Maastrichtian slope deposits (Monte Acuto Limestones) from the southern sector shows that they make up a N–S-prograding system of coalesced lobes composed of high-density turbidites and subordinate debrites. We infer that preconditional factors (e.g., platform progradation, tectonic oversteepening, and high pore pressures in the margin and upper-slope deposits) for triggering the density flows varied along strike of the platform, but the main controlling factors were the activity of the prominent strike-slip Mattinata Fault and the propagation of tremor energy to its near- and far-field regions: large earthquakes triggered thick (up to 40 m) and amalgamated Albian–Cenomanian debrites in proximity (south of) to the fault, whereas the subdued effect of the tremors triggered thinner debrites (5–10 m) and rock falls in the far-field region north of the fault. Moreover, predominantly high-density turbidite deposits were emplaced in the far-field region during lower-magnitude earthquakes. During the Maastrichtian the thick succession of high-density turbidites and scattered thick debrites south of and adjacent to the Mattinata Fault may record an overall quiescent period of the fault. The results are of relevance for understanding the spatiotemporal distribution of density-flow deposition along carbonate platforms in tectonically active regions—in particular with respect to the activity of large strike-slip faults.
Publisher
Society for Sedimentary Geology
Reference108 articles.
1. Argnani, A., Rovere, M., and Bonazzi,C., 2009, Tectonics of the Mattinata Fault, offshore south Gargano (southern Adriatic Sea, Italy): implications for active deformation and seismotectonics in the foreland of the Southern Apennines: Geological Society of America, Bulletin, v.121, p.1421– 1440. 2. Arnott, R.W.C., 2012, Turbidites, and the case of the missing dunes: Journal of Sedimentary Research, v.82, p.379– 384. 3. Berra, F., Lanfranchi, A., Smart, P.L., Whitaker, F.F., and Ronchi,P., 2016, Forward modelling of carbonate platforms: sedimentological and diagenetic constraints from an application to a flat-topped greenhouse platform (Triassic, Southern Alps, Italy): Marine and Petroleum Geology, v.78, p.636– 655. 4. Bertotti, G., Casolari, E., and Picotti,V., 1999, The Gargano Promontory: a Neogene contractional belt within the Adriatic Plate: Terra Nova, v.11, p.168– 173. 5. Blair, T.C., and McPherson,J.G., 1999, Grain-size and textural classification of coarse sedimentary particles: Journal of Sedimentary Research, v.69, p.6– 19.
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