Late Miocene evolution of the eastern Deep Algarve basin: Interaction of bottom currents and gravitational processes in a foredeep setting

• Published in: Marine and petroleum geology 2022-07, Vol.141, p.105695, Article 105695
• Main Authors: Ng, Zhi Lin, Hernández-Molina, F. Javier, Ledesma, Santiago, Sierro, Francisco J., Duarte, Débora, Llave, Estefanía, Roque, Cristina, Arnáiz, Álvaro
• Format: Article
• Language: English
• Subjects: Bottom currents; Deep Algarve basin; Deep-marine sedimentation; Gravitational processes; Late Miocene; Paleo-Mediterranean Outflow Water
• ISSN: 0264-8172; 1873-4073
• DOI: 10.1016/j.marpetgeo.2022.105695

Foreland basins are normally dominated by turbidite deposits in the early stages of their evolution. In this work, we show evidences of bottom current influence in the Algarve basin, which evolved as a foredeep basin of the Betic-Rif orogeny, during which the paleo-Mediterranean Outflow Water (MOW) was active through the Betic and Rifian corridors. Seismic interpretation identified four stages of sedimentary evolution (Stages I-IV) in the eastern domain of the Deep Algarve basin. Stages I and II correspond to the Late Miocene contourite depositional system during the late Tortonian to early Messinian, interrupted by the emplacement of the allochthonous unit of the Gulf of Cádiz. Bottom currents reworked the initial turbiditic sediments in the eastern Deep Algarve basin, as the downstream continuation of the Guadalquivir sands turbidite system, forming contourite drifts prior to the severe weakening or cessation of the paleo-MOW around mid-Messinian. Stages III and IV represent the evolution of the turbidite system with a lack of bottom current influence, through the downstream translation and lateral migration of meandering submarine channels, and their subsequent abandonment, during the late Messinian. The Tortonian to Messinian evolution of bottom current is modulated by the water-mass exchange between the Mediterranean and the Atlantic due to the shallowing of gateway sills and subsequent restriction of the paleo-MOW through the Betic and Rifian gateways around ∼6.4 Ma. Tectonic and glacioeustatic changes related to the orbital forcing exerted control over both the turbidite and contourite depositional systems, where tectonic pulses of about 400-kyr dictated their large-scale morphosedimentary evolution and interactions. •3D seismic analysis of a foredeep setting influenced by the Betic-Rif Orogeny.•Sedimentary evolution consists of four stages reflecting the interactions of deep-marine sedimentary processes.•Earlier stages show bottom current dominance with deposition of Late Miocene contourite or mixed depositional system.•Later stages show gravity flow dominance with deposition of Guadalquivir sands turbidite system after paleo-MOW restriction.•Tectonic and glacioeustatic factors control the large-scale morphosedimentary evolution.