Landforms and soils - Mediterranean Mountain Environments - page 76

Figure 4.3 A small glacial laguna with permanent water during the summer season (photo by
the authors). ( A full colour version of this figure appears in the colour plate section )
the ridge line. Consequently, the lagoons are at high altitudes, between 2600 and
3100 m. They are not very deep but there are many basins, and melting of snow and
ice results in sheets of water that fill all the little depressions. During the summer the
loss of water through seepage plus the action of the sun and wind causes many of
these pools to dry out. The remaining ponds are restricted to a very small area (less
than 100 km 2 ) around the highest peaks of the chain. The highest pond is Laguna
del Corral at 3086 m, while at lower altitudes, between 2600 m and 2700 m, other
ponds are located, including Lavanderos de la Reina, the Carnero, Misterioso and
Puesto del Cura.
In the Sierra Nevada's Lanjaron Valley, Mulhacen Valley, Laguna Seca and Cor-
ral del Veleta, preglacial surfaces have been reworked to a greater or lesser degree
and deposits formed during different cold episodes (Sanchez et al., 1988; Sanchez,
1990; Gomez et al., 1992). The soil parent materials are mainly composed of mica
schists of the Nevado-Filabride Complex (Diaz de Federico and Puga, 1976). The
Sierra Nevada summits, as described above, have an east-west alignment over a dis-
tance of approximately 90 km with an asymmetrical setting that divides the northern
slopes from the southern ones. This morphology affects the climate of the differ-
ent slopes; the dry conditions in the northern areas, exposed to the arid climate of
central Andalusia, differ from those of the Mediterranean coastal areas. This envi-
ronment, with a Mediterranean rainfall regime, mountain slopes and undercutting
ephemerally flowing rivers, is a template for many of the mountain environments
of the Mediterranean region, and results drawn from here could have widespread
implications for many of the slopes in the region. The Alpujarras is a deep valley
running parallel to and south of the crest of the Sierra Nevada (Figure 4.4). It is