Deducciones paleoclimáticas a partir del studio de una secuencia sedimentaria alternante de espeleotemas y sedimentos detríticos en Sima Engañá, Sierra de las Nieves (Málaga)

The study of chemical precipitation and detrital sediments in caves is a good tool as proxy record of past climate change and then for paleoclimatic reconstruction and interpretation of a region due to these sediments are very conservative. In Sima Engañá, an analysis on stratigraphic sequence of an alternating set of detrital sediments and speleothems has been made. The samples dated of different families of speleothems using the uranium series (²³⁰Th/²³⁴U), a coal cape on the top of the sequence using δ¹⁴C have allowed to identify the paleoclimatic cyclicity in the last 465.000 years BP. Also characterization of detrital sediments by X-ray diffraction and granulometry studies show this alternating sequence. The different sedimentary phases are related to pulses with high or low energy of the endokarstic water. Detrital sediment deposition is linked to the energy flows that transported mainly allochthonous sediments. The development of speleothems is associated both with the laminar water pulses in the formation of flowstones and with the dripping by the formation to the stalagmites. The analysis of the results shows that these stages, related with tractive sediments or speleothems, took place in a time period ranging from 464,019 ± 16,668 years BP, isotope stage 13 (Middle Pleistocene) to 525 ± 15 years BP, isotopic stage 1 (Holocene) all calibrated ages.