Las erupciones históricas de Tenerife (Canarias) en sus aspectos vulcanológicos, petrológico y geoquímico

Resumo

This work is a synthesis of the graduation thesis that, under the direction of Dr. A. Hernández-Pacheco, was realised in the Department of Petrology of Universidad Complutense de Madrid. The lecture took place in 1981. The primitive study comprised a research of the historical documents and manuscripts with the description of eruptions that are not transcribed here. In the present works, the situation and mapping of the historical volcanoes as well as their petrological and geochemical characteristics are included. Although the work in the field was done at 1/10.000 scale, it is presented here in a much more reduced scale due to the requeriments of the format. The research for organic material in order to date some uncertain prehistoric eruptions was unfruitful. Since 1341, 18 volcanic eruptions have ocurred in the Canary Islands. This is the study for the 8 reptions that took place in Tenerife, of which only 5 are well located and studied. For the 1492 eruption a very probable location is suggested. The duration of the eruptions varies between 10 and 92 days. The surface covered in each of the eruptions varies between 2,2 and 10,4 Km2. All the materials emitted represents the 1,5%, of the whole surface of the island. The morphology of lava flows is mainly of the "aa" type. Petrologically there are basalts s. 1. beloning to the alkaline series. Regarding their geochemical characters they can be subdivided into tephrites, basanitoids and basalts, in this order of abundance.