Skip to Main Content
Book Chapter

Anisotropy of Magnetic Susceptibility (AMS) as a Flow Indicator

January 01, 2015


The anisotropy of magnetic susceptibility (AMS) technique is a rapid petrophysical method used to infer magma flow directions within dykes as well as other igneous intrusions. Samples for AMS study were collected from dykes along the upper part of the NE Rift Zone (NERZ) of Tenerife, Canary Islands, Spain. Of the analysed dykes, 28 have interpretable normal magnetic fabrics. These 28 dykes are therefore suitable to assess the magma flow direction using the imbrication of the magnetic foliation plane from paired dyke margins and/or the overall trend and plunge of the magnetic lineations. AMS fabrics show downwards and upwards flow that could be related to flank and summit eruptions. Overall, however, the direction and sense of magma flow does not follow a specific trend across the NERZ, suggesting that the dykes are supplied by local shallow-level reservoir(s) underneath the ridge or are responding to variations in the local stress field across the axis of the rift zone. The variability of the AMS fabrics suggests a rather complicated propagation mode of magma within the dykes of the NERZ, contrasting with the common assumption of uniform magma propagation within rift zones. Our data therefore support the notion that magma propagation beneath active volcanic systems is inherently more complex than simple subvertical flow from source to final emplacement level, which bears on volcanic hazards worldwide.

You do not currently have access to this article.
Don't already have an account? Register

Figures & Tables


Geological Society, London, Special Publications

The Use of Palaeomagnetism and Rock Magnetism to Understand Volcanic Processes

M. H. Ort
M. H. Ort
Search for other works by this author on:
M. Porreca
M. Porreca
Search for other works by this author on:
J. W. Geissman
J. W. Geissman
Search for other works by this author on:
Geological Society of London
ISBN electronic:
Publication date:
January 01, 2015




A comprehensive resource of eBooks for researchers in the Earth Sciences

This Feature Is Available To Subscribers Only

Sign In or Create an Account

This PDF is available to Subscribers Only

View Article Abstract & Purchase Options

For full access to this pdf, sign in to an existing account, or purchase an annual subscription.

Subscribe Now