ISSN:
1365-3121
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Geosciences
Notes:
Using the example of the Isle of Skye in Scotland, we investigate the influence of pressure variations in upper-crustal magma reservoirs on the development of rift-type normal faulting around central volcanoes. The regional synmagmatic stress regime is of strike-slip type in Scotland during the Lower Tertiary. During a prolonged period of overall high pressure in the Skye magma reservoir (gabbro intrusion stage), crustal extension results from the injection of basaltic dykes parallel to the trend of the far-field maximum stress. During a subsequent period of pressure decrease in the reservoir (granites intrusion stage) normal faults trending parallel to the dykes are initiated. These faults tilt the upper-crustal blocks along with the former dyke swarm and associated lava pile. Finite-element modelling shows that a decrease of magma pressure in a circular cavity may lead, as in Skye, to a change from a regional strike-slip to a local rift-type normal stress regime.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1046/j.1365-3121.2003.00494.x
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