Anisotropy of magnetic susceptibility (AMS) study of magma transport in Mount Calanna Dyke swarms of Mount Etna, Italy

Abstract

<p>Dykes and Sills are the primary subvolcanic bodies that transport magma from the deep-seated magma reservoir or from the shallow magma chamber. The mechanism of magma transport and emplacement in dyke swarms is significant, as their passage from magma chamber through the crust to the surface or near-surface settings can provide valuable information on source and how magma has interacted with crustal rocks.</p><p>Here, we are presenting the preliminary findings obtained from the Anisotropy of Magnetic Susceptibility (AMS) and Palaeomagnetic analysis to study the magma transport mechanism and emplacement history of  Mount Calanna dyke swarms of Mount Etna. In order to find their magnetic fabrics, we systematically sampled 45 oriented hand samples from 11 dykes where at least two samples were collected from both dyke boundary and centre. Using the obtained AMS fabrics, we attempt to find the emplacement mechanisms of dykes in Mount Calanna and its relationship to Mount Etna.</p><p>AMS technique provides valuable information regarding the dyke emplacement such as whether the Mount Calanna dykes are feeders, and whether they are the result of polycentric, vertical or lateral magma flow. Based on the intersection of the AMS axis with the dyke plane, we were able to identify two classes, one where the dyke plane intersects with the maximum principal susceptibility axes (Kmax) and the other where the dyke plane intersects with the minimum principal susceptibility axes (Kmin). Nevertheless, the variation in the shape parameter from centre to boundary shows the effect of shear, magma viscosity and the host rock strength on magma emplacement. The Paleomagnetic techniques enable us to unravel the relative timing of the injection of the dykes and the possible tectonic control on their emplacement.</p>