Straits and seaways: controls, processes and implications in modern and ancient systems

Abstract

Straits and seaways are connections between basins, key areas for exchange and transfer of water, heat, biota and sediments, and they can influence regional and global climate. A better understanding of straits/seaway dynamics, their evolution and preserved deposits is therefore fundamental to reconstruct the paleoecology, paleogeography and stratigraphy of interconnected basins. Straits and seaways are also important for understanding climate dynamics in Earth's past, and safely exploit energy resources (fossil and renewable). This Special Publication aims at improving the knowledge on this topic, and at providing a comprehensive collection of state-of-the-art works bringing together complementary disciplines. Even though studies on modern and ancient straits and seaways exist, they are not necessarily conceived towards a better geological understanding of these features as depositional systems in their own right. In this article we emphasize the geological importance of straits and seaways, summarizing the content and key findings of the contributions on this topic. The articles included in this volume explore four main research themes related to straits and seaways: (a) occurrence and classification; (b) morphological features, facies and stratigraphic variability, sedimentary processes and dynamics; (c) tectonic and climatic controls, their feedback with climate changes; (d) palaeogeographic reconstructions and preservation of associated deposits.

Tectonic control on the palaeogeographic evolution of thrust‐top basins at the active margin of the Guadalquivir Basin (central Betic Cordillera, S Spain)

“…The decametric dunes of Facies 6 are indicative of sediment movement under the action of strong currents. Submarine dunes of similar sizes form in extremely high-energy settings, such as in recent straits where the velocity of water masses increases substantially due to constriction of the cross-sectional area (Dalrymple, 2023;Longhitano, 2018;Rossi et al, 2023). Gigantic dunes of similar dimensions occur in other localities of the Betic Cordillera linked to ancient straits connecting the Atlantic and the Mediterranean Sea (Betzler et al, 2006;Martín et al, 2001Martín et al, , 2009Martín et al, , 2014Puga-Bernabéu et al, 2023).…”

Element Geochemical Characteristics and Geological Significance of Mudstones from the Middle Jurassic Shaximiao Formation in Sichuan Basin, Southwest China

“…Estimated pCO 2 fluctuations in the Sichuan basin coincide with paleotemperature variations in the low paleolatitudes of the Northern Hemisphere. In addition, according to the seaway dynamics model, which emphasizes the potential significance of the seaway for heat transport, major modifications in Mesozoic oceanic current patterns may have a significant influence on a large-scale, abrupt climate change and potentially govern transformations between warm/cool or dry/humid climate modes . As Korte (2015) proposed, the uplift of the North Sea Dome that impeded northward oceanic heat transport was considered to cause an especially abrupt mid-latitude cooling of seawater by as much as 10 °C in the north–south Laurasian Seaway during the Jurassic .…”

“…In addition, according to the seaway dynamics model, which emphasizes the potential significance of the seaway for heat transport, major modifications in Mesozoic oceanic current patterns may have a significant influence on a large-scale, abrupt climate change and potentially govern transformations between warm/cool or dry/humid climate modes. 79 As Korte (2015) proposed, the uplift of the North Sea Dome that impeded northward oceanic heat transport was considered to cause an especially abrupt mid-latitude cooling of seawater by as much as 10 °C in the north–south Laurasian Seaway during the Jurassic. 80 Interestingly, Shaximiao Formation shows an earlier climate change from humid to seasonally arid during Middle Jurassic indicated by small cumulative thickness of dark-gray shale and deficiency of a coal bed comparing with equivalent stratigraphic records in the Junggar Basin, Qaidam Basin, and Santanghu Basin.…”