Climatic control on palaeohydrology and cyclical sediment distribution in the Plio-Quaternary deposits of the Guadix Basin (Betic Cordillera, Spain)

Abstract

A cyclical pattern can be observed in the central sector of the Guadix Basin (southern Spain) in the Late Pliocene-Quaternary alluvial fan deposits prograding into its axial valley. A climatic significance has been attributed to this cyclicity on the basis of sedimentological and preliminary isotopic studies. The progradation phases of the alluvial fans are here attributed to more arid time intervals in which the vegetation cover would be less developed, erosion and sediment supply would be higher, and base level would be lower. In contrast, the time intervals during which the fluvial system sediments dominated the area are inferred to be wetter and base level higher, with vegetation cover retaining the soils and preventing erosion. Permanent water supply to the river would therefore facilitate the aggradation of the floodplain and prevent progradation of the fans. Starting from a litho-, bio-and magnetostratigraphical frame provided for the area, an age is assigned to the alternation of the reddish sediments of the transverse alluvial fans and the greyish to white fluvio-lacustrine sediments of the *Manuscript Click here to view linked ReferencesThis is a previous version of the article published in Quaternary International. 2015International. , 389: 56-69. doi:10.1016International. /j.quaint.2015 2 axial drainage system. A cyclicity of ca. 100 ky has been identified in most of the alluvial fan progradation phases, falling within Milankovitch high-frequency eccentricity periodicities. Correlation of the phases with insolation curves is accordingly discussed as a possible origin for the cyclicity. Finally, the results offer new insights into early hominin occupation patterns in the region, through the identification of predictable resources of permanent fresh water that would have remained available throughout the recorded time span (that includes the Early-Middle Pleistocene transition) even during times of aridification.

Imprint of Messinian Salinity Crisis events on the Spanish Atlantic margin

“…This facilitates increased erosion and hence increases coarse-grained sediment concentration in river run off resulting in enhanced silt input. Similar models have been proposed for cyclic continental deposits elsewhere (Harvey et al 1999, Pla-Pueyo et al 2015.…”

Astronomical tuning for the upper Messinian Spanish Atlantic margin: Disentangling basin evolution, climate cyclicity and MOW

“…A similar mechanism is proposed to explain the cyclic depositional changes in the Plio-Quarternary continental deposits of the Guadix Basin (Pla-Pueyo et al, 2015). These authors explain cyclical changes between alluvial and fluvial deposits to changes in vegetation cover and subsequent erosion.…”

Paleoenvironmental Evolution of Continental Carbonates in West-Central Brazil

“…2), and they can be separated into seven sedimentary facies: Calcretized polymitic conglomerate -Cpc; Calcretized brecciated wackestone -Cbw; Oncolithic packestone -Op; Fossil-rich wackestone -Fw; Quartz sand-rich wackestone -Qw; Laminated tufa -Lt; Massive tufa -Mt. Despite the particularities of the studied region, most facies described here have been identified in other continental carbonate environments elsewhere (Arenas-Abad et al 2000, Arenas et al 2014, Carthew et al 2003, Gandin and Capezzuoli 2008, Pla-Pueyo et al 2009, Pla-Pueyo et al 2015.…”