The glaciers of the Central-Western Pyrenees

Abstract:

The action of the Quaternary glaciers in the Central-Western Pyrenees is responsible for the various kinds of the relief features found there, including the well-configured cirques, large U-shaped valleys, overexcavation basins, detailed shapes, and moraine accumulations of very different ages. With almost continuous divides exceeding 2500 m and very complex basins that integrate numerous tributary valleys, the main Pyrenean glaciers reached over 30 km in length and 400 m in thickness, descending to altitudes of c. 800 m. The largest glaciers were those in the Gállego and Ésera valleys. Their size is attributed to the large extents of their headwaters and the altitudes of their highest peaks. The long tradition of studies on Pyrenean glacial processes allows us to trace a fairly complete sequence of events, especially during the Last Glacial Cycle. Thus, a considerable amount of data confirm that the maximum ice extent did not occur during the global Last Glacial Maximum (20 ka or MIS-2) but at 60 ka, that is, during MIS-4. There is indirect evidence of a glacial advance between 22 and 19 ka as well as successive advances and retreats in the Oldest Dryas and Younger Dryas during deglaciation. Moreover, small reactivations likely took place during the Holocene from 6 ka, especially during the Little Ice Age. It is also interesting to note that scattered moraine remains, erratic blocks, and fluvioglacial terraces corresponding to previous glacial cycles have been found in some valleys.

Año de publicación:

2021

Keywords:

• Glacial landforms
• Deglaciation
• Glacial asynchrony
• Central-western pyrenees

Fuente:

scopus