Testing the record of climate-related cyclicity in microbial lamination: An example from Miocene oncolites in the Ebro Basin, Spain

Pérez-Rivarés, F.J. ; Pardo, G. ; Arenas, C. (Universidad de Zaragoza)

Resumen: This work tests the relationship between quasi-periodic climate-linked parameters and cyclicity recorded through microbial lamination using spectral analysis of time series based on lamina thickness and luminance, as well as C and O stable isotope data. Three oncolites of the Ebro Basin were used: specimens C4-1 and C4-31 from a lacustrine bed dated at 13.8 My, and specimen VD-13 from a fluvial bed whose age is younger than 12 My. Lamination consists of alternating light and dark calcite laminae, which correspond to crystal size and porosity variations. Composite light and dark laminae can be seen by the naked eye. Spectral analysis based on the thickness and luminance measurements of simple light–dark lamina couplet successions revealed that the three specimens had recurrent periods of 2.5, 3 and 10–13. On the hypothesis that each simple light–dark lamina couplet represents a 1-year duration, the 2.5 and 10–13 periods can be related to the 2.5-year quasi-biennial oscillation and the 11-year Schwabe sunspot cycle, respectively. Other less frequent periods present around 5 and 7, together with period 3, could be related to the most typical modes of the North Atlantic Oscillation and/or El Niño Southern Oscillation. The periods at 19–23, present in specimen C4-31, can be correlated with the 22-year Hale sunspot cycle. The 10–13 and 19–23 periods were also detected using the δ13C and δ18O values of successive laminae in specimen C4-31. These data suggest that solar irradiance variations influenced the characteristics of the oncolite laminae, through temperature and precipitation. Although the studied oncolites do not present an optimal thickness lamination pattern for spectral analysis, their lamination is capable of registering periodic climatic variations, and these results provide further evidence that microbial laminations can serve as high-resolution records of climate and climate-linked cycles over different time scales.

Idioma: Inglés

DOI: 10.1016/j.sedgeo.2023.106563

Año: 2024

Publicado en: Sedimentary Geology 460 (2024), 106563 [17 pp.]
ISSN: 0037-0738

Financiación: info:eu-repo/grantAgreement/ES/MINECO/CGL2013-42867-P
Financiación: info:eu-repo/grantAgreement/ES/MINECO/PID2019-106440GB-C22

Tipo y forma: Article (Published version)

Área (Departamento): Área Estratigrafía (Dpto. Ciencias de la Tierra)