The field relations of the Las Cañadas Volcanoes, Tenerife, Canary islands

Abstract

The subaerial basement shield of Tenerife is composed largely of basanite and ankaramite flows intercalated with tuffs and agglomerates. Near the centre of the islands, in the area now known as Las Canadas, extensive volcanism of intermediate and salic composition followed the shield building stage and produced the Upper and Lower Canadas Series. These Series are exposed in the walls of a large collapse structure, the Portillo-Tauce escarpment. Detailed mapping of the structures within this escarpment indicates that the volcanics were erupted from a series of poorly defined centres along an east-west fissure system, one of two or possibly three such systems that have dominated the major sub-aerial volcanic growth of Tenerife.