12,000

We have over 12,000 students, from over 100 countries, within one of the safest campuses in the UK

93%

93% of Lancaster students go into work or further study within six months of graduating

Home > Research > Publications & Outputs > Repeated fracture and healing of silicic magma ...
View graph of relations

« Back

Repeated fracture and healing of silicic magma generate flow banding and earthquakes?

Research output: Contribution to journalJournal article

Published

Journal publication date12/2003
JournalGeology
Journal number12
Volume31
Number of pages4
Pages1089-1092
Original languageEnglish

Abstract

Textures in an exceptionally preserved effusive rhyolite conduit at Torfajokull, Iceland, indicate that rising magma repeatedly fractured and healed at shallow levels in the conduit (RFH process). Anastomosing tuffisite veins filled by fine-grained juvenile clasts were generated by shear fracture of highly viscous magma in the glass transition interval. Welding of the particulate material during subsequent deformation led to thorough healing of veins, allowing repeated fracture of the same body of magma. We propose that the RFH process is a rechargeable trigger mechanism for hybrid seismicity and show that the time scale of the process and the fractures formed by it are consistent with the repeat time and magnitude of hybrid earthquakes during silicic eruptions. The RFH process may also form the flow banding that is nearly ubiquitous in obsidian.

Bibliographic note

Geological Society of America, P.O. Box 9140, Boulder, CO 80301-9140 USA (http://www.geosociety.org)

Related research outputs