The Cathedral / La Catedral
Mount Teide or, in Spanish, El Teide, is the highest elevation of Spain and the islands of the Atlantic (it is the third largest volcano in the world from its base) is 3.718 meters. Is an active volcano which last erupted in 1909 from the El Chinyero vent on the Santiago (northwestern) rift and is located on Tenerife, Canary Islands. The volcano and its surroundings comprise the Teide National Park (Parque Nacional del Teide in Spanish). The park has an area of 18900 ha and was named a World Heritage Site by UNESCO on June 29, 2007. It is also from the end of 2007 one of the Twelve Treasures of Spain. Territorially belongs to the municipality of La Orotava.
At 3718 m above sea level, and approximately 7500 m above the floor of the Atlantic Ocean, Teide is the highest mountain in Spain, highest point in the Atlantic Ocean and the 13th highest mountain in the European Union (highest mountain not in the Alps).(Note: The actual summit stands 3 meters (10 ft) higher than the triangulation station, and associated bench mark, which has an altitude of 3,715 m (12,188 ft)). The island of Tenerife itself is the third largest volcanic ocean island on Earth by volume. Teide is also the third highest volcano on a volcanic ocean island. It is also unstable and possibly in a more advanced stage of deformation and failure than the much publicized Cumbre Vieja. The United Nations Committee for Disaster Mitigation designated Teide as a Decade Volcano, because of its history of destructive eruptions and its proximity to several large towns, of which the closest are Garachico, Icod de los Vinos and Puerto de la Cruz. Teide together with its neighbour Pico Viejo and Montaña Blanca form the Central Volcanic Complex.
Within the Teide National Park occur many different volcanic features of which La Catedral is but one. The supplied coordinates are of this rock formation. Parking is available at N 28º 13.392’ – W 16º 37.838 and from there choose the best view of The Cathedral.
La Catedral is one of the best examples of “phonolyte necks” in the Cañadas del Teide crater.
Phonolite is a rare igneous, volcanic (extrusive) rock of intermediate (between felsic and mafic) composition, with aphanitic to porphyritic texture.
The name phonolite comes from the Greek meaning (more or less) "sounding stone" because of the metallic sound it produces if an unfractured plate is hit, hence the English name clinckstone.
Phonolite is unusual in that it forms from a highly silica undersaturated melt by low degrees of partial melting (less than 10%) of highly aluminous lower crustal rocks such as tonalite, monzonite and metamorphic rocks. Melting of such rocks to a very low degree promotes the liberation of aluminium, potassium, sodium and calcium via melting of feldspar, with some involvement of mafic minerals. The melt formed is silica undersaturated (i.e.; quartz is absent from the melts or solidified rocks), with feldspathoid species dominating over feldspar species in the melt.
Phonolite occurrences are associated with a few geological processes and tectonic events, which can lead to the melting of appropriate precursor lithologies. These include intracontinental hotspot volcanism, such as may form above mantle plumes covered by thick continental crust. A-type granites and alkaline igneous provinces are usually associated with phonolites. Phonolites may also be produced by low degree partial melting of underplates of granitic material in collisional orogenic belts.
Phonolites, as they are products of low degree partial melts, are silica undersaturated, and have feldspathoids in their normative mineralogy.
Mineral assemblages in phonolite occurrences are usually abundant feldspathoids (nepheline, sodalite, hauyne, leucite and analcite) and alkali feldspar (sanidine, anorthoclase or orthoclase), and rare sodic plagioclase. Biotite, sodium rich amphiboles and pyroxenes along with iron rich olivine are common minor minerals. Accessory phases include titanite, apatite, corundum, zircon, magnetite and ilmenite. Phonolites are silica under-saturated, as illustrated by the position of phonolite in the TAS classification and QAPF diagrams.
The idea behind this EarthCache is to show you how “phonolite necks” are formed.
During the eruption the rock in the volcano conduit was molten (1).
After the eruption the magma cooled down very slowly and solidified. As the rock contracted, prismatic joints were formed (2).
Long afterword, erosion and meteorization destroyed the volcano. However, the highly resistant rock of the volcano conduit was left standing out on the landscape (3).
To validate your “found” log for this EarthCache you need to:
1 - On photo 1's legend there is an (A), please e-mail me what is exactly written at its place on the "TheCathedral" infoboard;
2 - Draw a sketch of The Cathedral with the estimated height of this rock formation and upload it.
3 - (Optional) Upload a photo of you and your GPSr with The Cathedral on the background.
ATTENTION: Any log without sketch upload will be deleted within a week’s time.
Las coordenadas dadas son de la formación rocosa. Puede aparcar en N 28º 13.392’ – W 16º 37.838 y desde ahí elegir el mejor local para mirar a La Catedral
Esta formación rocosa es uno de los mejores ejemplos de “pitón fonolítico” en la cratera de Cañadas del Teide, situado a mas de 2000 metros de altitud.
Con esta Earthcache se pretende enseñar como son formados los “pitones fonolíticos”.
Durante la erupción la roca de la chimenea volcánica estaba fundida (1).
Después de la erupción, el magma solidificó, enfriándose muy lentamente; al contraerse la roca se formaron fisuras con forma de prisma (2).
Mucho tiempo después la erosión destruyó el volcán. La roca de la chimenea volcánica quedó sobresaliente en el paisaje (3).
Para tener su log validado usted tiene que:
1 - En la legenda de la foto 1 hay un (A), por favor envíe-me un e-mail con lo que estay exactamente escribido en su lugar en el infoboard de "La Catedral";
2 - Hacer un pequeño dibujo de La Catedral con su altura estimada y hacer su upload;
3 - (Opcional) Hacer el upload de una foto suya con el GPSr y La Catedral como fondo.
ATENCIÓN: Logs sin el upload del dibujo serán apagados en una semana.