Late Miocene–early Pliocene planktonic foraminifer event-stratigraphy of the Bajo Segura basin: A complete record of the western Mediterranean

• Published in: Marine and Petroleum Geology
• Main Authors: Corbí, Hugo, Soria Mingorance, Jesús Miguel
• Other Authors: Universidad de Alicante. Departamento de Ciencias de la Tierra y del Medio Ambiente, Cambios Paleoambientales
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2016
• Subjects: Biostratigraphy; Planktonic foraminifera; Tortonian; Messinian Salinity Crisis; Pliocene; Betic Cordillera; Bajo Segura basin; Estratigrafía
• Online Access: http://hdl.handle.net/10045/62034; https://doi.org/10.1016/j.marpetgeo.2016.08.004

The Bajo Segura basin (eastern Betic Cordillera) has one of the most complete late Miocene–early Pliocene marine records of the western Mediterranean. An updated planktonic foraminifer zonal scheme based on recent astronomically tuned biozones is presented for this interval, documenting a complete succession of biostratigraphic markers, from biozone MMi9 (earliest Tortonian) to MPl3 (latest early Pliocene), of likely significance for regional-scale correlation throughout the Mediterranean. The findings reveal a series of intrazonal events (some unreported until now in the Mediterranean Neogene basin), including the particularly interesting two influxes of the Globorotalia miotumida group during the Tortonian. These biostratigraphic findings are the basis for a framework of the major allostratigraphic units in the basin based on planktonic foraminifer event-stratigraphy: synthems Tortonian I, Tortonian II, Tortonian-Messinian I, Messinian II, and Pliocene. In addition, the timing of the main tectono-sedimentary and palaeogeographic events throughout the basin's evolution has been further constrained. Our results suggest that, at least in the Bajo Segura basin, the late-Messinian barren interval (non-distinctive zone) can be considered an ecobiostratigraphic zone (cenozone) characterized by dwarf fauna of planktonic foraminifera. Consequently, the Bajo Segura composite section can be regarded as a biostratigraphic reference section for Neogene basins in the Betic Cordillera and hence also in the Western Mediterranean. This paper was written in the context of the Paleoenvironmental Changes research group (University of Alicante, VIGROB-167) and supported by project GRE14-05 (University of Alicante).