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Volcanic and sedimentary processes during formation of the Saefell tuff-ring, Iceland

Published online by Cambridge University Press:  03 November 2011

Clyde A. Leys
Affiliation:
BP Minerals International Ltd, R. Padre Antonio Macedo 60, 7540 Santiago do Cacem, Portugal.

Abstract

The Recent Saefell tuff-ring on Heimaey, Iceland was formed by surtseyan activity in shallow seawater. The tuff-ring has a basal diameter of about 3 km, a maximum rim height of 188 m above sea-level and a crater diameter of 1300 m. Three tuff-units are recognised, separated by unconformities on and inside the crater rim due to syndepositional slumping. The crater contains a nested rim which was constructed above slumped crater tuffs. Directional data indicate strongly directed blasts to the SW at a late stage in the activity.

Throughout the volcanic activity, base-surges formed antidunes, U-shaped channels, vesiculated tuffs, small ripples and plastering structures. One antidune reflects a decrease in surge flow power during deposition and subsequent slumping due to base-surge drag and instabilities developed during growth. On the basis of field characteristics, the structures are divided into those deposited by hot, dry, fast-moving surges and those by cooler, wet, slow-moving surges. Base-surges are compared with turbidity currents and deposition of distinct structures by the head, body and tail regions is interpreted.

Type
Research Article
Copyright
Copyright © Royal Society of Edinburgh 1983

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References

7. References

Allen, J. R. L. 1982. Sedimentary structures: their character and physical basis. 2. DEV IN SEDIMENTOL 30B.Google Scholar
Ballance, P. F. 1964. Streaked-out mud ripples below Miocene turbidites, Puiriri Formation, New Zealand. J SEDIMENT PETROL 34, 91101.CrossRefGoogle Scholar
Camus, G., Boivin, P., De Goer de Herve, A., Gourgaud, A., Kieffer, G., Mergoil, J. & Vincent, P. M. 1981. Le Capelinhos (Faial, Azores) vingt ans après son eruption: le modele eruptif “Surtseyan” et les anneaux de tufs hyaloclastiques. BULL VOLCANOL 44, 3142.CrossRefGoogle Scholar
Fisher, R. V. 1977. Erosion by volcanic base-surge density currents: U-shaped channels. BULL GEOL SOC AM 88, 1287–97.2.0.CO;2>CrossRefGoogle Scholar
Fisher, R. V. & Waters, A. C. 1970. Base surge bed forms in maar volcanoes. AM J SCI 268, 157–80.CrossRefGoogle Scholar
Heiken, G. 1971. Tuff-rings: examples from the Fort Rock-Christmas Lake Valley Basin, South-Central Oregon. J GEOPHYS RES 76, 5615–26.CrossRefGoogle Scholar
Jakobsson, S. P. 1968. The geology and petrography of the Westmann Islands. A preliminary report. SURTSEY RES PROG REP 4, 113–29.Google Scholar
Jakobsson, S. P. 1978. Environmental factors controlling the palagonitisation of the Surtsey tephra, Iceland. BULL GEOL SOC DEN 27, 91105.Google Scholar
Jakobsson, S. P. 1979. Outline of the petrology of Iceland. JOKULL 29, 5773.Google Scholar
Jopling, A. V. & Walker, R. G. 1968. Morphology and origin of ripple-drift cross lamination, with examples from the Pleistocene of Massachusetts. J SEDIMENT PETROL 38, 971–84.Google Scholar
Kjartansson, G. 1967. Nokkrar nyar C14 aldursakvardanir. NATTURUFRAETHINGURINN 36, 126–41.Google Scholar
Kokelaar, B. P. 1983. The mechanism of Surtseyan volcanism. J GEOL SOC LONDON 140, in press.CrossRefGoogle Scholar
Leys, C. A. 1982. Volcanic and sedimentary processes in phreatomagmatic volcanoes. Unpublished Ph.D. thesis, Leeds University.Google Scholar
Lorenz, V. 1973. On the formation of maars. BULL VOLCANOL 37, 183204.CrossRefGoogle Scholar
Lorenz, V. 1974. Vesiculated tuffs and associated features. SEDIMENTOLOGY 21, 273–91.CrossRefGoogle Scholar
Machado, F., Parsons, W., Richards, A. F. & Mulford, J. W, 1962. Capelinhos eruption of Fayal volcano, Azores, 1957–58. J GEOPHYS RES 67, 3519–29.CrossRefGoogle Scholar
Moore, J. G. 1967. Base-surge in recent volcanic eruptions. BULL VOLCANOL 30, 337–63.CrossRefGoogle Scholar
Segerstrom, K. 1950. Erosion studies at Paricutin, State of Michoacan, Mexico. BULL U S GEOL SURV 965–A.Google Scholar
Sheridan, M. F. 1972. Textural analysis of Surtsey tephra. A preliminary report. SURTSEY RES PROG REP 6, 150–2.Google Scholar
Skipper, K. 1971. Antidune cross-stratification in a turbidite sequence, Chloridorme Formation, Gaspe, Quebec. SEDIMENTOLOGY 17, 5168.CrossRefGoogle Scholar
Straaten, L. M. J. U. van. 1953. Rhythmic pattern on Dutch North Sea beaches. GEOL MIJNB 15e, 3143.Google Scholar
Thorarinsson, S. 1967. Surtsey—The new island in the North Atlantic. New York: Viking Press.Google Scholar
Tryggvason, E. 1972. Precision levelling in Surtsey. SURTSEY RES PROG REP 6, 158–62.Google Scholar
Walker, G. P. L. 1971. Grain-size characteristics of pyroclastic deposits. J. GEOL 79, 696714.CrossRefGoogle Scholar
Wohletz, K. & Sheridan, M. F. 1979. A model of pyroclastic surge. SPEC PAP GEOL SOC AM 180, 177–94.Google Scholar