We performed an extensive field-based structural analysis supported by a remote sensing study of tectonic and volcanic features of Askja’s calderas and of the eastern flank of the hyaloclastite massif. Askja consists of three nested calderas (namely Kollur, Askja and Öskjuvatn) located within a hyaloclastite massif along the NNE-SSW trending Icelandic MDPB. An ideal place to investigate their mutual relationship is the Askja central volcano in Iceland. This is also likely in accordance with a northward increase in the spreading rate along the Icelandic MDPB.Īctivity within magmatic divergent plate boundaries (MDPB) focuses along both regional fissure swarms and central volcanoes. Therefore, Askja represents an intermediate tectono-magmatic setting for volcanoes located in a slow divergent plate boundary. This is different from Krafla volcano (to the north of Askja) dominated by regional structures and GrÃmsvötn (to the South) dominated by local structures. Our results highlight that the Askja volcano displays a balanced amount of regional (fissure-swarm related) and local (shallow-magma-chamber related) tectonic structures along with a mutual interaction among these. Volcanic vents and dikes are preferentially distributed along the caldera ring faults however, they follow the NNE-SSW regional structures when located outside the calderas. Structural trends around the Öskjuvatn caldera are typically rim parallel. In the massif, volcano-tectonic structures trend N 10° E to N 40° E, but they vary around the Askja caldera being both parallel to the caldera rim and cross-cutting on the Western side. We performed an extensive field-based structural analysis supported by a remote sensing study of tectonic and volcanic features of Askja's calderas and of the eastern flank of the hyaloclastite massif. Trippanera, Daniele Ruch, Joël Acocella, Valerio Thordarson, Thor Urbani, StefanoĪctivity within magmatic divergent plate boundaries (MDPB) focuses along both regional fissure swarms and central volcanoes. Interaction between central volcanoes and regional tectonics along divergent plate boundaries: Askja, Iceland
0 Comments
Leave a Reply. |