Tidal strait depositional model revised

This paper presents a revised depositional model for tidal straits, building upon a previous prototype published in 2013. That model introduced a subdivision of tidal straits into four main sectors: (A) a strait-center, (B) a dune-bedded zone, (C) strait-end zone, and (D) a strait-margin zone, indicating as each of these zones are identifiable based on their distinctive hydrodynamics, sedimentary structures, and grain-size distributions. The model also provided predictive sedimentological columns and a main stratigraphic framework useful for the identification of ancient strait-fill successions preserved in outcrop or subsurface. While it marked a significant advancement in the understanding of both modern and ancient tidal straits, its applicability was constrained by the limited number of case studies on which it was based.

The new model presented in this paper integrates insights from 29 modern and 22 ancient tidal straits to enhance the understanding of strait-scale sedimentary processes and their stratigraphic signatures. The revised framework reaffirms the presence of the four principal depositional zones but introduces some novel element, including: (i) the recognition of sedimentary facies also in Zone A, such as gravel ribbons, previously considered as a sole bypass environment; (ii) the presence of supercritical-flow structures as an early process precursor of current-dominated tidal sedimentation; (iii) an expanded variety of bedforms in Zone B, including tidal sand ridges; (iv) a new link between shallow-water tidal processes and deeper contouritic deposits in Zone C; and (v) the inclusion of delta deflection and sediment reworking along strait margins or Zone D. The updated model additionally offers improved stratigraphic criteria for recognizing ancient tidal straits in the rock record, integrated with specific types of ichnofacies, and emphasizes their relevance to paleogeographic reconstructions and subsurface resource exploration. Finally, the study identifies key areas within modern straits with potential for tidal and wave energy harvesting, highlighting the broader implications of tidal straits for sustainable energy strategies.