Fábrica magnética (ASM) de diques andesíticos autunienses con enclaves corticales del sector de Maicas (Anticlinal de Montalbán, Cadena Ibérica Oriental)

Abstract

The Montalban Anticline (Eastern Iberian Chain) represents a matchless framework of Autunian hypovolcanic calc-alkaline (dykes and sills) intrusions within the Iberian Chain. In the Maicas sector (NO of Montalban Anticline) the dykes contain several types of metamorphic and granitic xenolites from a deep origin. The xenolites can be considered as passive markers and thus the dykes of this sector constitute very interesting bodies in order to determine both the flow regime characteristics and the related stress regime. The application of the anisotropy of the magnetic susceptibility technique (AMS) to one dyke of the Maicas sector, where a high content in metamorphic and granitic xenolites occur, reveals a geometrical pattern of both the magnetic foliation and lineation within the dyke which is consistent with a turbulent flow regime linked to the xenolites emplacement. The obliquity between the mean magnetic lineation and the dyke wall, strongly suggest an emplacement mode of the magma linked to an oblique extension regime which is consistent with the structural Autunian framework in the Iberian Chain