The Western Adriatic shelf clinoform: energy-limited bottomset

Abstract

Clinoforms on modern shelves and slopes, as well as in ancient rock records, are widely recognized as a fundamental building element of continental margin growth. Regardless of their dominant lithology, clinoforms are composed of three geometric elements: topset, foreset and bottomset. Traditionally, much emphasis in the study of clinoforms was put on the geometry of the topset, viewed as the most energetic portion of a clinoform and studied to discern if aggradation was active rather than erosional truncation, and on the foreset, the area with the highest sediment accumulation rates. Here we focus on the factors forcing clinoforms to taper out and on the inferred mechanisms for bottomset creation. We base our analysis on muddy shelf clinoforms, a particular class of clinoforms that is typical of low-gradient settings and is characterized by a substantial component of shoreparallel sediment transport. This paper is based on a large dataset of CHIRP-sonar profiles, bathymetric and isopach maps of the Late Holocene clinoform on the Adriatic shelf, where integrated stratigraphic studies from sediment cores allow a very high (in some cases century-scale) chronological resolution. Knowledge on the dominant oceanographic regime affecting sediment dispersal and, ultimately, clinoform development, has been recently refined during the EuroSTRATAFORM collaboration. Muddy clinoforms are markedly three-dimensional features that cannot be entirely understood solely on two-dimensional shore normal sections. We suggest that this class of clinoform is advection dominated and that an increase in the energy regime at the toe of the foreset may prevent sediment from reaching beyond the transition to the bottomset region.

Clinoforms and clinoform systems: Review and dynamic classification scheme for shorelines, subaqueous deltas, shelf edges and continental margins

“…5). This contrasts with the accumulation rate and thickness profiles of constructional clinoforms, characterized by sedimentation rates greatest along the foreset portion and significantly lower towards both the topset and the bottomset (e.g., Alexander et al, 1991;Leithold, 1993;Michels et al, 1998;Pirmez et al, 1998;Walsh et al, 2004;Palinkas and Nittrouer, 2006;Cattaneo et al, 2007;Pellegrini et al, 2015) (Figs. 10-18).…”

“…1988; Everts and Reijmer, 1995;Leeder, 1999;Bosence, 2002;Bosence andWilson, 2002a, 2002b;Pomar et al, 2002;Eberli et al, 2004;Maurer et al, 2010;Lanfranchi et al, 2011;Betzler et al, 2015) and siliciclastic systems (e.g., Schlee et al, 1979;Steckler et al, 1999;Adams and Schlager, 2000;Tesson et al, 2000;Howell and Flint, 2002a, 2002cCattaneo et al, 2003Cattaneo et al, , 2007Holgate et al, 2014Holgate et al, , 2015Pellegrini et al, 2018). Clinothems may be also formed by very shallow-water gypsum platform accretion (Tucker, 1991;Patruno et al, 2018, in press).…”

“…6-7 ka before present, with the waning of the rate of post-glacial eustatic rise (Summerhayes et al, 1978;Field and Roy, 1984;Stanley and Chen, 1996;Morales, 1997;Chen et al, 2000;Stouthamer and Berendsen, 2000;Kuehl, 2000a, 2000b;Hernández-Molina et al, 2000a;Ta et al, 2002a;Hori et al, 2002Hori et al, , 2004Cattaneo et al, 2003Cattaneo et al, , 2007Palinkas and Nittrouer, 2006;Liu et al, 2006Liu et al, , 2007aLiu et al, , 2007bGiosan et al, 2006b;Le Dantec et al, 2010;Qiu et al, 2014).…”

“…8; Patruno et al, 2015a). Delta-scale subaqueous clinoforms are subject to efficient basinal transport and sorting: therefore, their facies, grain-size, geomorphology and architecture are all more uniform than in shoreline clinoforms (e.g., near-linear plan-view morphology) (Driscoll and Karner, 1999;Kuehl, 2000a, 2000b;Chen et al, 2000;Hernández-Molina et al, 2000a;Cattaneo et al, 2003Cattaneo et al, , 2007Liu et al, 2004Liu et al, , 2006Liu et al, , 2007bLobo et al, 2005;Qiu et al, 2014;Patruno et al, 2015aPatruno et al, , 2015b.…”

Comparison of Split Window Algorithms for Retrieving Measurements of Sea Surface Temperature from MODIS Data in Near-Land Coastal Waters

“…The seafloor morphology is characterized by the progressive increase of the forest dip in this coastal area. Cattaneo et al [49] argued that the Gargano Promontory, which is very prominent toward the Adriatic Sea, acts as an obstacle to a sediment dispersal system as it changes the direction and velocity of the western Adriatic coastal current. Lesina Lagoon is situated north of the promontory of Gargano (Figure 1f,g) and is about 22 km long, with a total area of about 51 km 2 .…”