gsminmag Mineralogical Magazine Mineralogical Magazine 0026-461X Mineralogical Society 10.1180/minmag.1998.62A.1.235 ⁴⁰Ar/³⁹Ar Data on Primary and Secondary Minerals of a Volcanic Series Affected by Burial Metamorphism: Example of a Cretaceous Andean Extensional Basin Feraud G. Géosciences Azur, UMR CNRS, Université de Nice-Sophia Antipolis, 06108 NICE cedex 02, France Aguirre L. Vergara M. Dpto. Geologia, Facultad de Ciencias Fisicas y Matemáticas, Universidad de Chile, Casilla, 13518, Correo 21, Santiago de Chile, Chile Morata D. Dpto. Cristalografia y Mineralogía, Estratigrafia, Geodinámica, Petrologia y Geoquímica. Facultad de Ciencias del Mar. Universidad de Cádiz. 11510 Puerto Real, Cádiz, Spain Robinson D. Department of Geology, Wills Memorial Building, University of Bristol, Queen's Road, Bristol BS8 1RJ, UK 1998 62A 1 444 445 Copyright © 1998, The Mineralogical Society 1998