1. ESR chronology of the endokarstic deposits of Galería complex (Sierra de Atapuerca, Spain).
- Author
-
Hernando-Alonso, Isabel, Moreno, Davinia, Ortega, Ana Isabel, Benito-Calvo, Alfonso, Alonso, María Jesús, Campaña, Isidoro, Parés, Josep María, Cáceres, Isabel, García-Medrano, Paula, Carbonell, Eudald, and Bermúdez de Castro, José María
- Subjects
ELECTRON paramagnetic resonance ,THERMOLUMINESCENCE dating ,ALLUVIUM ,RADIOMETRIC methods ,PLEISTOCENE Epoch ,ELECTRON spin resonance dating - Abstract
The Galería karstic complex, situated within the Atapuerca Multilevel Karst system (Burgos, Spain), records an impressive sedimentary sequence from the Early to Middle Pleistocene period. One of the notable features of this complex is the presence of thick fluvial deposits (waterlain facies), providing a detailed record of the transitional moment between the formation of the middle and lower Atapuerca karst levels. Examining these sediments, barely dated thus far, is crucial for gaining a comprehensive understanding of fluvio-karstic dynamics at the Atapuerca site. In our study, we conducted dating analyses on sediment samples from different areas of the Galería complex using Electron Spin Resonance (ESR) on quartz grains (4 samples from Covacha de los Zarpazos and 1 from Tres Simas Norte outcrops) and paleomagnetism (12 samples). The aim was to refine the chronological framework of the Galería complex, providing ages for the formation of these passages. Considering the geological context, our results revealed underestimated Aluminium (Al) ESR ages ranging from 372 ± 78 to 569 ± 80 ka in Covacha de los Zarpazos, along with consistent dates of 1184 ± 120 and 1001 ± 302 ka in Covacha de los Zarpazos and Tres Simas Central, respectively. Our results agree with previous estimates obtained through luminescence dating methods, indicating Middle Pleistocene ages for the samples. In contrast, reverse polarity estimates disagree with those from radiometric dating methods, except for samples ZAR1501 and TSC1501. Caution should be taken when interpreting these ages, as various geological factors including leaching processes from upper zones, post-sedimentary structures, and lithological variations may indicate alterations in the primitive geochemical composition of the sediment. Consequently, these factors can potentially affect the total Dose rate parameter and introduce uncertainties into the age calculations. • We aimed to date interior fluvial sediments preserved in Galería Complex (Atapuerca). • For this purpose, ESR and Paleomagnetism samples were taken in Covacha de los Zarpazos and Tres simas central. • The results showed two distinct data sets: Ages of approximately 1 Ma ago were associated with Arlanzón T3 and T4 terraces. • Anomalous ages may be caused by a potential overestimation of the annual dose, resulting from diagenetic processes. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF