The Geological Evolution
                       of Tenerife

Origin and Formation of the Canary Islands

The Canary Islands lie some 2000 miles distant from the major Mid-Atlantic plate boundary, and thus occupy an intra-plate setting. Along with the Hawaiian island chain, the Canaries and in particular Tenerife, represent a significant example of intra-plate orogenesis. The origin of the archipelago has been much disputed. Two main hypothesis have been proposed (Araña and Carracedo, 1978).

Hot-Spot Theory

Early research postulated that the evolution of the Canary islands was related to ‘hot spot’ volcanism. This theory implies the existence of a localized magmatic focal point in the mantle, above which the lithospheric plate moves in accordance with the regional tectonic dynamics (west-east in the Canarian tectonic setting). Volcanism directly related to this magmatic focal point gives rises to a series of volcanic seamounts which are successively displaced by continental drift. Ultimately this process results in a island chain ordered from youngest to oldest with distance from the hot-spot, with active volcanism evident in only the youngest islands. The Hawaiian island chain is the classic exemplar of the hot-spot theory. Evidence for the theory in the Canaries lies in the spatial-age structure of the archipelago, with the oldest islands ((Fuerteventura and Lanzarote) in the east and the youngest islands (Hierro and La Palma) in the west. Evidence of contemporary and historic volcanic activity in Lanzarote, Gran Canaria and Tenerife, however, serve to cast doubt on the plausibility of this hypothesis.

Regional Orogenesis and Faulting
More recently, it has been suggested that volcanism in the Canary Islands is related their position in a transit zone from thick continental to thin oceanic lithosphere and the effects the Alpine orogeny. This theory relates the volcanic evolution of the Canaries to regional scale faults developed during the uplift of the nearby Atlas mountains in the Miocene. These large fractures were thought to be periodically active during successive cycles of compression and distension (extension) during the orogeny, with volcanic episodes related to the periods of distention which facilitated the out-pouring of magma and the formation of basaltic shield volcanoes (Anguita, 1977).

This theory appears to be corroborated by the position of the main volcanic hazards at in the Archipelago which are related to active, SW-NE trending structural rift-type zones (SRTZs), locally called "dorsales" ("ridges"). Arana and Carracedo (ibid.) also identify regional faults as the cause of strong recent earthquake activity in the region (e.g., 1989 in Santa Cruz de Tenerife).

Site last updated May 2002 : r.middleton@hull.ac.uk