Determining the depth of magma storage by investigation of samples from the eruption on La Palma 1971
Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
The Canary islands are formed by a slow moving hotspot, from Fuerteventura 20 Ma to el Hierro 1.2Ma years old and La Palma is in the shield building stage of evolution. La Palma had its last eruption 1971 and has had seven eruptions since 1430, which makes it the most active of the islands in our times. The samples consist of host lavas, basanites, and mafic/ultramafic and felsic xenoliths, alkali gabbros and syenites respectively. Minerals in the lavas and the alkali gabbro xenolith samples are clinopyroxene, olivine, amphibole and plagioclase, the clinopyroxenes are zoned. Forsterite content in the olivines increases at the rim for the xenoliths and decreases for the host lavas. While magnesium number in the clinopyroxenes decreases towards the rim. The Fe-Mg partitioning indicates that there were points of equilibrium between the clinopyroxenes and their host lavas, which was calculated to temperature, pressure and depth indicating 62-74km for the xenoliths and 23-35km for the host lavas. The temperatures and pressures were 1184-1205°C with 6-10 kbar for the host lavas compared to 1316-1341°C and 17-20 kbar for the xenoliths.
Place, publisher, year, edition, pages
2013. , 22 p.
, Självständigt arbete, 71
canary islands, volcanism, magma storage
IdentifiersURN: urn:nbn:se:uu:diva-206827OAI: oai:DiVA.org:uu-206827DiVA: diva2:645548
Subject / course
Geophysical Science (HGO)
Bachelor Programme in Earth Science
2013-06-05, Hambergsalen, Institutionen för geovetenskaper, Uppsala universitet, Villavägen 16B, 752 36 Uppsala, Uppsala, 11:20 (English)
Barker, Abigail, Dr
Hellqvist, Magnus, PhD