EGU22-4521, updated on 07 Jan 2023
EGU General Assembly 2022
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Deglaciation timing in the Atlantic Iberian mountains: an example from lake sediments in Serra da Estrela (Portugal)

Armand Hernández1, Ricardo N. Santos2, Teresa Rodrigues2,3, Dulce Oliveira2,3, Filipa Naughton2,3, João Moreno4, Pedro Raposeiro5, Santiago Giralt6, Alberto Sáez7, Manel Leira8, Graciela Gil-Romera9, Pedro Costa4,10, Ricardo M. Trigo4, Gonçalo Vieira11, Mark Abbott12, Melissa Griffore12, Sandra Gomes2,13,14, and Alexandre M. Ramos4
Armand Hernández et al.
  • 1Centro de Investigacións Científicas Avanzadas (CICA), Faculty of Sciences, University of Coruña, A Coruña, Spain
  • 2Portuguese Institute of Sea and Atmosphere, (IPMA), Lisbon, Portugal
  • 3Center of Marine Sciences (CCMAR), Algarve University, Faro, Portugal
  • 4Instituto Dom Luiz (IDL), Faculdade de Ciências, Universidade de Lisboa, Portugal
  • 5Centro de Investigação em Biodiversidade e Recursos Genéticos (CIBIO), Rede de Investigação em Biodiversidade e Biologia Evolutiva (InBIO) - Laboratório Associado, Pólo dos Açores, 9500-321 Ponta Delgada, Portugal
  • 6Geosciences Barcelona (Geo3BCN-CSIC), Consejo Superior de Investigaciones Científicas, Barcelona, Spain
  • 7Dep. of Earth and Ocean Dynamics. University of Barcelona. Spain
  • 8BioCost Research Group, Facultade de Ciencias and Centro de Investigacións Científicas Avanzadas (CICA), Universidade de A Coruña, A Coruña, Spain
  • 9Dept. Ecology, Philipps-Marburg Universität, Germany and IPE-CSIC, Zaragoza, Spain.
  • 10Department of Earth Sciences, University of Coimbra, Portugal
  • 11Centre of Geographical Studies, Institute of Geography and Spatial Planning, University of Lisbon, Lisboa, Portugal
  • 12Department of Geology and Environmental Science, University of Pittsburgh, PA, USA
  • 13Quaternary Environments and Geoarchaeology, Department of Geography, School of Environment, Education and Development, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
  • 14Department of Geography and Geology, Edge Hill University, Ormskirk, Lancashire, United Kingdom

The Serra da Estrela range in Central Portugal is a key  region to explore the Last Glacial termination in the Atlantic region of Iberia. We present the Late Glacial and Holocene record of Lake Peixão to reconstruct past environmental and climatic conditions at decadal timescales. We retrieved an 8.5m long core in the central and deepest zone of the lake. From the base to the top, the sediment core is composed of i) a thick layer (aprox. 0.5 m) of gravel-to-sand quartz clasts; ii) an alternation of one meter thick grey to pale-brown sandy deposits; and iii) homogeneous dark brown and pale-brown organic-rich muddy facies (ca. 7 meters). Using a Bayesian statistical model based on 16 radiocarbon dates using pollen concentrated samples and 210Pb measurements, we have developed an age-depth model covering the last ca. 14.6 ka, recording the onset of the lake at that time. Lake and mire records previously published in the area generally support this chronology for the formation of proglacial lakes. In addition, the proposed timing for the disappearance of the Serra da Estrela glaciers has been based on Cosmic-Ray Exposure dating (in situ cosmogenic 36Cl) of exposed moraine boulders and glacially polished bedrock surfaces. These results indicate that the end of the glacier’s presence in Serra da Estrela occurred at ca. 14.2 ka BP (during the Bølling-Allerød Interstadial). Therefore our results broadly suport the timing of the end of the deglaciation at the Serra da Estrela and highlight the value of lake sedimentary records. Moreover, the availability of last termination and Holocene highly-resolved sediments from Lake Peixão is likely to record very valuable evidence of climatic and environmental changes at decadal timescales extending from the last deglaciation, through the Holocene. This new multi-proxy data of the Lake Peixão sedimentary sequence will enable comparisons to other decadal-resolved records and support further investigations from the Mediterranean Iberian region.
The financial support for this work was possible through the following FCT project: HOLMODRIVE—North Atlantic Atmospheric Patterns Influence on Western Iberia Climate: From the Late Glacial to the Present (PTDC/CTA-GEO/29029/2017).


How to cite: Hernández, A., Santos, R. N., Rodrigues, T., Oliveira, D., Naughton, F., Moreno, J., Raposeiro, P., Giralt, S., Sáez, A., Leira, M., Gil-Romera, G., Costa, P., Trigo, R. M., Vieira, G., Abbott, M., Griffore, M., Gomes, S., and Ramos, A. M.: Deglaciation timing in the Atlantic Iberian mountains: an example from lake sediments in Serra da Estrela (Portugal), EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-4521,, 2022.