Paleoclimate reconstruction of the last 36 kyr based on branched glycerol dialkyl glycerol tetraethers in the Padul palaeolake record (Sierra Nevada, southern Iberian Peninsula)
Identificadores
URI: http://hdl.handle.net/10481/73076Metadatos
Mostrar el registro completo del ítemAutor
Rodrigo-Gámiz, Marta; García-Alix Daroca, Antonio; Jiménez Moreno, Gonzalo; Ramos-Román, María J.; Camuera Bidaurreta, Jon; Toney, Jaime L.; Sachse, Dirk; Anderson, R. Scott; Sinninghe Damsté, Jaap S.Materia
GDGTs distribution Mean annual air temperature reconstruction pH reconstruction Continental sediment record Southern Spain Heinrich stadials DansgaardeOeschger events
Fecha
2022-02-26Referencia bibliográfica
Rodrigo-Gámiz, M., García-Alix, A., Jiménez-Moreno, G., Ramos-Román, M.J., Camuera, J., Toney, J.L., Sachse, D., Anderson, R.S., Sinninghe Damsté, J.S., 2022. Paleoclimate reconstruction of the last 36 kyr based on branched glycerol dialkyl glycerol tetraethers in the Padul palaeolake record (Sierra Nevada, southern Iberian Peninsula). Quaternary Science Reviews, 281, 107434
Resumen
Quantitative continental climate reconstructions covering the last glacial cycle from the Iberian Peninsula
are scarce. In order to fill this gap, we obtained for the first time a high-resolution mean annual air
temperature (MAAT) record based on the distribution of specific bacterial membrane lipids (i.e.,
branched glycerol dialkyl glycerol tetraethers; brGDGTs) from the last 36.0e4.7 kyr palaeolake record
recovered by the Padul-15-05 sedimentary core (Padul, Sierra Nevada, southern Iberia). The fractional
abundance of the three major groups of GDGTs present in the Padul sediments, GDGT-0, crenarchaeol
and the summed brGDGTs, is comparable with that of other shallow and small (<10 km2) European lakes.
Despite variations in the lithology in the studied section, the GDGT composition remains relatively stable,
except for the uppermost 116 cm of the record, representing the ephemeral/emerged lake stage, which is
characterized by higher crenarchaeol fractional abundances. The identification of a specific brGDGT that
has only been detected in anoxic lakes provides evidence for in-situ brGDGT production in the water
column and/or sediments in the Padul palaeolake. Its presence/absence probably denotes a succession of
periods with a variable oxygen content in the bottom waters of the palaeolake. MAAT was reconstructed
based on the distribution of brGDGTs using an African lake calibration and ranged between 12 and 20 C.
A new Bayesian calibration to mean temperature of Months Above Freezing (MAF) depicts similar
temperature variations with a mean absolute difference of 0.7 C. The MAAT reconstruction in the Padul
palaeolake for the 36.0e4.7 kyr period reveals similarities with climate variability described at highlatitudes
and in the westernmost Mediterranean area during this interval, showing cold conditions
during the last three Heinrich Stadials and the Younger Dryas and warm conditions during the Dansgaard
eOeschger interstadials (7e1) and the B€olling-Aller€od period. Despite the more stable and warm general
climate conditions during the Early and Mid-Holocene, rapid centennial-scale temperature changes are
registered in the Padul palaeolake in good agreement with variations observed in the Mediterranean
forest record.