Insights on the climatic evolution at the pre-Jaramillo to Jaramillo transition in Europe using mineralogical analysis of the Quibas palaeontological site (Early Pleistocene, southern Iberian Peninsula)

© The Authors, 2023. This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International License (for details please see http://creativecommons.org/licenses/by/4.0/), which permits use, copy, adaptation, distribution, and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source. This document is the Published version of a Published Work that appeared in final form in Spanish Journal of Palaeontology. To access the final edited and published work see https://doi.org/10.7203/sjp.27562The palaeontological site of Quibas is a karst outcrop with an age between 1.1 and 0.9 Ma (late Early Pleistocene). It represents the unique continuous sequence of terrestrial vertebrates of pre-Jaramillo to Jaramillo age in Europe. It is formed by two main structures: Quibas-Sima (divided into units QS-1 to QS-7) and Quibas-Cueva (QC-1– QC-6). In this work, we analyse the mineralogical composition of the sediments that form the stratigraphic units of Quibas-Sima using X-ray diffraction analysis, electrical conductivity, ion chromatography and optical emission spectrometry, to evaluate climatic trends in the sequence. Preliminary results indicate that there is an increase in the proportions of carbonates, gypsum and halite from QS-2 towards QS-4 and QS-5 (1.07–0.99 Ma), suggesting a progressive decrease in precipitation in south-eastern Iberian Peninsula a million years ago. Our data are consistent with the onset of a glacial phase, which is supported by the progressive disappearance of taxa related to forests and water bodies in Quibas-Sima, such as the flying squirrel Hylopetes sp. and the semiaquatic shrew Neomys sp., in favour of the appearance of taxa linked to open areas such as the Montpellier snake (Malpolon monspessulanus) and the snub-nosed viper (Vipera latastei). El yacimiento paleontológico de Quibas es un afloramiento kárstico con una edad comprendida entre 1,1 y 0,9 Ma (Pleistoceno Inferior tardío). Representa la única secuencia continua de vertebrados terrestres de edad pre-Jaramillo a Jaramillo de Europa. Está formado por dos estructuras principales: Quibas-Sima (dividida en las unidades QS-1 a QS-7) y Quibas-Cueva (QC-1 a QC-6). En este trabajo se estudia la composición mineralógica de los sedimentos que conforman las unidades estratigráficas de QuibasSima, a través e análisis de difracción de rayos X, conductividad eléctrica, cromatografía iónica y espectrometría de emisión óptica por plasma de argón, con el objetivo de evaluar tendencias paleoclimáticas en la secuencia. Los resultados preliminares indican que hay un aumento en las proporciones de carbonatos, yesos y halita desde QS-2 hacia QS-4 y QS-5 (1,07–0,99 Ma), lo que sugiere una progresiva disminución de las precipitaciones en el sureste peninsular hace un millón de años. Los datos son consistentes con el inicio de una fase glaciar, lo cual viene apoyado por la desaparición progresiva en Quibas-Sima de taxones afines a bosques y cursos de agua estables como la ardilla voladora Hylopetes sp. y el musgaño Neomys sp., en favor de la aparición de taxones ligados a espacios abiertos como la culebra bastarda (Malpolon monspessulanus) y la víbora hocicuda (Vipera latastei)