The glaciers of the Southeastern Pyrenees

Abstract The Southeastern Pyrenees extend eastward along the north-south line that the Segre River traces with its Andorran tributary, the Valira River. The main massifs correspond to the Tossa Plana de Lles-Calmquerdos-Carlit to the west, the Puigmal-Bastiments-Costabona in the center—both within the Cerdanya basin (Upper Segre Valley)—and the Ripolles district (headwaters of the Ter Valley) to the east. The discovery and analysis of the glacial landforms existing in these massifs started at the end of the 19th century, but it was not until the end of the 20th century when remarkable advances were made, complemented in the early 21st century with the establishment of the glacial chronology. Glacial landforms are limited to the mountain regions and include a great variety of landforms, ranging from extensive areas in the higher massifs modeled by ice field, valley glaciers >10 km long, and small glacial cirques in the lower mountains of the Pre-Pyrenean massifs. The main glacial advance in the Southeastern Pyrenees took place between 80 and 35 ka. Moreover, the glacial advance occurred during the global Last Glacial Maximum (gLGM) and reached almost the same extent as the previous advance. After a massive retreat at 19–20 ka, the glaciers readvanced at c. 17–16 ka. Most of the cirques were deglaciated at c. 15 ka, and rock glaciers formed afterward. Only in the highest cirques (2800 to 2900 m), north- and east-exposed, small glaciers were formed during the Younger Dryas. No glacial activity has been detected during the Holocene. This glacial evolution is very similar to that occurred in the northeastern slope of the Pyrenees but the spatiotemporal pattern of glacial oscillations since the Last Glacial Maximum is significantly different than in the Central Pyrenees, where the climate was more influenced by the Atlantic Ocean.