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Proceedings 10 : "Pozu del Xitu"

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by Martin Laverty

The Picos de Cornion is the western massif of the Picos de Europa mountains in Northern Spain. The expedition was to the part of this area covered by the Province of Asturias (Oviedo), but Leon and Santander also have territory there. The mountains rise to 2596m within 30km of the aptly named Costa Verde: the Green Coast. The climate is strongly influenced by oceanic effects and is rather wet. Rainfall at Bufferara near Los Lagos is recorded as 2119mm per annum, with June, July, and August being slightly drier than other months. Despite this, the summer can bring periods of prolonged drizzle and fog, as well as severe thunderstorms. The latter may be accompanied by hailstones or winds of prodigious size and intensity: both have been seen to wreck tents with great ease! Permanent snowfields are a prominent feature of the peaks and snowplugs persist in dolines and shafts down to at least 1250m in some cases. The spring thaw must be an important time for continuing cave development with impressive flooding. The evidence for such annual events is particularly clear in caves at lower levels, where new vegetation chokes appear each year in sites far above observed summer water levels. Vegetation is generally sparse above the level of Los Lagos, and is probably decreasing in extent with overgrazing by goats, sheep, cows, and, sometimes, horses.

Further details of the biology of the area are contained in : Proposals for the Biological Management of the Parqua Nacional de la Montana de Covadonga, Asturias, Spain. Discussion Papers in Conservation, University College, London, No. 25 (1979).

A Note on Map Coverage of the Area

In order to reach the expedition area, road maps obtained from the Spanish National Tourist Office or made by Firestone (Costa Verde y Picos de Europa - 1:125,000) are quite adequate, and usually in agreement one with another. At a more detailed level, no really accurate maps appear to exist. The most accurate looking map is the Mapa de los Tres Macizos de los Picos de Europa at 1:50,000 scale produced by the Federacion Española de Montañismo (Alberto Aguilera 3, Madrid 15; the same address as the Comision Nacional de Espeleologia, from whom permits are required to cave in Spain). This map is on sale only in Potes, Aliva, Posada de Valdeon, and Arenas de Cabrales, and is basically the same as the relevant portions of the Mapa Nacional sheets 55, 56, 80 and 81. However, the Lambert grid on those is not reproduced, so map references must be given in terms of latitude and longitude (W of Madrid, not Greenwich!). Another 1:50,000 map is produced by the Federacion Asturiana de Montañismo (Melquades Alvarez 16, 1. Izda., Oviedo) and this gives full details about the network of mountain refuges. Its contouring is far less detailed than the other map, but the rivers, settlements and paths are generally more accurate. The most used map of the area, and the most easily available, is the 1:25,000 Mapa Topográphico - Excursionista produced by Editorial Alpina (Apartado de Correos, 3, Granollers) entitled Picos de Europa I Macizo Oriental. This comes complete with a guide book to walks in the area, but this can be rather misleading or confusing to use. This problem is exacerbated if comparison is made with the other maps! The map which is considered best by experienced members of the SIE group of cavers from Barcelona is another 1:25,000 map produced by J. R. Lueje for a book called Picos de Cornion, published by Gijon in 1968. Unfortunately, this is not easily available.