Skilling, I. P. (1993) Incremental caldera collapse of Suswa volcano, Gregory Rift Valley, Kenya. Journal of the Geological Society, 150 (5). pp. 885-896.
Full text not available from this repository.Abstract
Suswa volcano, located at 1°10'S, 36°20'E, is Quaternary in age (<0.4 Ma), dominantly trachytic-phonolitic in composition, and has two calderas. Regional extension was a fundamental control on caldera collapse, providing pathways for the siting, drainage and recharge of magma chambers. Caldera I collapse was associated with magmatic overpressure from volatile exsolution, magma-water interaction, influx of denser magma and magma drainage at depth. Trachybasalt ash, trachyte globular-ash ignimbrites, trachyte pumice lapilli air-fall tuffs and carbonate-trachyte ignimbrites characterize the initial subsidence. Air-fall tuffs, erupted during caldera collapse at Longonot, are interbedded, suggesting a regional collapse event. Incremental, but dominantly Valles-type, collapse continued with the eruption of trachyte agglutinate flows from concentric ring-fractures outside the caldera ring-fault (Ring-Feeder Zone) and trachyte pumice lapilli air-fall tuffs from west caldera I. Following caldera I collapse, phonolite lava flows were erupted from the caldera floor. Centrally-erupted phonolite lava flows led to the construction of Ol Doinyo Onyoke lava cone. A pit-crater on the cone was a precursor to the collapse of caldera II, both of which were generated entirely by magma withdrawal. Regional decompression caused ring-fault bounded, block-resurgence of the caldera floor
| Item Type: | Article |
|---|---|
| Journal or Publication Title: | Journal of the Geological Society |
| Subjects: | G Geography. Anthropology. Recreation > GE Environmental Sciences |
| Departments: | UNSPECIFIED |
| ID Code: | 22689 |
| Deposited By: | ep_ss_importer |
| Deposited On: | 20 Jan 2009 12:04 |
| Refereed?: | No |
| Published?: | Published |
| Last Modified: | 26 Jul 2012 16:04 |
| Identification Number: | |
| URI: | http://eprints.lancs.ac.uk/id/eprint/22689 |
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