Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Repeated fracture and healing of silicic magma generate flow banding and earthquakes?
AU - Tuffen, Hugh
AU - Dingwell, D. B.
AU - Pinkerton, Harry
N1 - Geological Society of America, P.O. Box 9140, Boulder, CO 80301-9140 USA (http://www.geosociety.org)
PY - 2003/12
Y1 - 2003/12
N2 - 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.
AB - 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.
KW - Flow banding
KW - obsidian
KW - volcanic earthquakes
KW - hybrid earthquakes
KW - tuffisite
KW - tuffisites
KW - magma fracture
KW - glass transition
KW - Iceland
KW - seismicity
KW - volcano
KW - lava dome
KW - lava domes
KW - seismic trigger mechanism
U2 - 10.1130/G19777.1
DO - 10.1130/G19777.1
M3 - Journal article
VL - 31
SP - 1089
EP - 1092
JO - Geology
JF - Geology
SN - 1943-2682
IS - 12
ER -