Valles, Aridane. 
One of the processes that generate more concern in the Canary volcanic landslides are known as gravitational origin of the valleys of La Orotava and Guimar in Aridane Tenerife and La Palma. Aridane
Valley on the island of La Palma is the gravitational valley most recent of those are located in the islands, 500,000 years, yet the most complex of those in the archipelago, so use it to explain the formation of these.
When first described, this type of landslides, it was considered that the collapse itself, is produced on a peculiar structure, which was called, sliding gaps, consisting of a fragmented bedrock on which hypothetically sliding, the rock above the sea (It is estimated that the remains found scattered on the seafloor surrounding the island, including in the form of large blocks, are the upper valleys of the current gravity). However. Let's see: -.
blocks located in the ocean does not seem consistent with a slip of the upper valley, the fragments are too large, even several miles.
-. A slide with these characteristics would considerably faster, resulting in well above effects detected, tsunamis, volcanic abrupt skid marks.
Aridane In the valley, the seniority of the points north of the valley (in the port of Tazacorte fig1 right point 1) do not coincide with the age of the items on the coastal cliff of the Time (part no sunken fig1 point 1 on the left) That is the sunken part of the valley seem to be missing the lower layers (oldest) that if they appear in the non-depressed known as the Time.
In Photo 1 shows how the sedimentary layer (left of the blue dots and point to the height of 1 left)) is a higher elevation than the valley sunk (its height is indicated by point 2) This can only mean that the sediment (point 2) were accumulated when the valley was at higher altitude (point 1 on the right) if the collapse had affected the upper layers of sediment deposited on top would have suffered the same fate.
ages in the non-depressed are much higher than the sunken, indicating that older layers have disappeared and the most recent are on them (is sinking deeper layers) on the right side of the photograph the valley is formed by rocks of less than 120,000 years to the right but the point 1 on the left is dated at 730,000 (two points were joined before the collapse and are separated by a layer of sediment from the boiler, then eroded the gullies of the anguish and Tenisca). Figure 1, the green arrow indicates the decreasing ages in the cliffs of the valley from 120,000 in 1 on the right.
It follows that the sinking of the valley is caused by the progressive sliding of the lower valley at depth, these layers are pressed by the weight of the upper slip under pressure may result in significant blocks dimensions, this leads to the formation of the future valley, following fractures favored by the management of the dams (arch bernoulli). In the model above, above the sedimentary area.
-. Another interesting detail is the volcanism characteristic of these valleys, and that does not follow the pattern of the rest of the island, in all these valleys, volcanic cones have a pattern itself, does not coincide with what would correspond in general direction of the island (the case Aridane Valley over 10 cones in a series of squares). Fig. 1.
slipped layers, very in depth, release the magma chamber, magma escapes through fractures (this is the reason why these volcanoes valleys do not follow the pattern of the rest of the island, the magma escapes through the fractures caused by the sinking of the magma chamber downloading). These fractures are typical of these valleys, which take the form of steps smoothed by erosion and activity arises from volcanic fissures between steps (red lines in Fig. 2)
in Fig. 2 red lines (volcano own valley) define the different segments formed in the collapse (which coincide with the municipalities that are at different heights)
green lines to the north and east of the valley (above left) are separated by a zone of sediment (lines in yellow) from the boiler, therefore, the valley is separated and turned south as it sank, the point of greatest subsidence is located in Tazacorte point 1 in Fig. 1, this last point is now a mere 50 meters above the sea (the area opposite the new pier Tazacorte is the point on which turns the whole valley, and the lowest point around him) in the model
we can see how the ravines of Sorrows and Tenisca follow a parallel pattern (the two green lines on the left, with blue markings) the volcanoes of the valley, red lines separate the various fractures in the valley. The
yellow lines of the model are the sediment of the caldera that occupied the area vacated by the valley, while the two canyons as already mentioned, contains the points that were united in their time.
can be seen as Bejenado is partly sunk in the valley, may be a possible fracture visible to the naked eye, the left is about 300 meters lower than the rest of Bejenado peak, the peak time and are also new 300 meters above the sunken valley area which were united.
In the next picture shows a panorama of the valley where you can see some volcanic cones of the valley and the gap between the plains and Tazacorte (the first two cities from the sea)
The following image shows the area of \u200b\u200bthe ravine from the anguish that coincides with the marked area Photo anterior.Ambas areas were married before the sinking, and follow parallel courses (there are two sides of a zipper) in Figure 1 correspond to the points 1 of the image taken from the sea.
