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Radiocarbon Dating Recent Volcanic Activity on Faial Island (Azores)

Published online by Cambridge University Press:  18 July 2016

José Madeira
Affiliation:
Departamento de Geologia, Faculdade de Ciências, Universidade de Lisboa, 1700 Lisboa, Portugal
A.M. Monge Soares
Affiliation:
Laboratório de Isótopos Ambientais, Departamento de Química, ICEN/INETI, 2685 Sacavém, Portugal
António Brum Da Silveira
Affiliation:
Departamento de Geologia, Faculdade de Ciências, Universidade de Lisboa, 1700 Lisboa, Portugal
António Serralheiro
Affiliation:
Departamento de Geologia, Faculdade de Ciências, Universidade de Lisboa, 1700 Lisboa, Portugal
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Abstract

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Recent fieldwork on the island of Faial (Azores) led to the establishment of a detailed volcanic stratigraphic sequence, which is composed of five main geological formations. One of them, the Caldeira Formation, comprising mainly pumice fall and flow deposits, was judged to be Holocene in age. Organic materials were found preserved in or below some of the pyroclastic deposits from this formation. Wood, charcoal, peat and soil samples were radiocarbon dated, permitting correlation of deposits from different sequences and the establishment of a chronological framework for the Caldeira volcanic activity. These materials yielded ages from ca. 10–1 ka bp. The average dormant interval in the Caldeira pyroclastic activity from 4–1 ka ago is ca. 400 yr, with eruptions approximately every 200–800 yr. This frequency of activity indicates that the Caldeira volcano is an active, dangerous structure that should be closely monitored.

Type
I. 14C in the Reconstruction of Past Environments
Copyright
Copyright © the Department of Geosciences, The University of Arizona 

References

Laughton, A. S. and Whitmarsh, R. B. 1974 The Azores-Gibraltar plate boundary. In Kristjansson, L., ed., Geodynamics of Iceland and the North Atlantic Area. Dordrecht, Reidel Publishing Co.: 6381.Google Scholar
Madeira, J., Brum da Silveira, A. and Serralheiro, A. 1994 Paleoseismicity and neotectonics of the Lomba do Meio fault zone, Faial, Azores. Annales Geophysicae 12(1): 68.Google Scholar
Serralheiro, A., Forjaz, V. H., Alves, C. A. M. and Rodrigues, B. 1989 Carta Vulcanológica dos Açores na Escala 1:15.000: Ilha do Faial. Centro de Vulcanologia do INIC/Serviço Regional de Protecção Civil dos Açores/Universidade dos Açores, eds., Ponta Delgada, 4 sheets.Google Scholar
Soares, A. M. M. 1989 O Efeito de Reservatório Oceânico nas Águas Costeiras de Portugal Continental Sacavém, Instituto de Ciências e Engenharia Nucleares (Laboratório Nacional de Engenharia e Tecnologia Industrial): 135 p.Google Scholar
Stuiver, M. and Pearson, G. W. 1993 High-precision bidecadal calibration of the radiocarbon time scale, ad 1950–500 bc and 2500–6000 bc. In Stuiver, M., Long, A. and Kra, R. S., eds., Calibration 1993. Radiocarbon 35(1): 123.Google Scholar
Stuiver, M. and Reimer, P. J. 1993 Extended 14C database and revised CALIB 3.0 14C age calibration program. In Stuiver, M., Long, A. and Kra, R. S., eds., Calibration 1993. Radiocarbon 35(1): 215230.Google Scholar