GARCIA-RUIZ, J.M., VALERO-GARCÉS, B., MARTI-BONO, C., GONZALEZ SAMPERIZ,
P. (2003): Asynchroneity of maximum glacier advances in the central Spanish
Pyrenees. Journal of Quaternary Science, 18 (1): 61-72.
Idioma / Language
Idioma
Resumen / Abstract
The deglaciation history
of the Escarra and Lana Mayor glaciers (Upper Gállego valley, central Spanish
Pyrenees) had been reconstructed on the basis of detailed geomorphological studies
of glacier deposits, sedimentological and palynological analyses of glacial lake
sediments and an accelerator mass spectrometry (AMS) 14 C chronology based on
minimum ages from glacial lake deposits. The maximum extent of the Pyrenean glaciers
during the last glaciation was before 30 000 yr BP and pre-dated the maximum advances
of the Scandinavian Ice Sheet and some Alpine glaciers. A later advance occurred
during the coldest period (around 20 000 yr BP), synchronous with the maximum
global ice extent, but in the Pyrenees it was less extensive than the previous
one. Later, there were minor advances followed by a stage of debris-covered glaciers
and a phase of moraine formation near cirque backwalls. The deglaciation chronology
of the Upper G´ allego valley provides more examples of the general asynchroneity
between mountain and continental glaciers. The asynchroneity of maximum advances
may be explained by different regional responses to climatic forcing and by the
southern latitude of the Pyrenees.
Palabras clave / Keywords
Last Glacial Maximum;
glaciers; upper G´ allego Valley; central Spanish Pyrenees