Magnetic fabrics of west coast dyke swarm from Deccan volcanic province, Maharashtra, India and their relationship with magma flow direction

Dykes are one of the primary subvolcanic bodies that transport magma from the shallow magma chamber or from the deep-seated magma reservoir. The mechanism of magma transport and emplacement in dyke swarms can contribute precious details on source and how magma has associated with crustal rocks. Here we are presenting the results obtained from the Anisotropy of magnetic susceptibility (AMS) on their mode of emplacement and to understand magma flow direction. AMS and rock magnetic studies were performed on 33 dykes located on the West coast of Maharashtra, (India) to determine the magma flow direction using magnetic fabric. Thermomagnetic curves and hysteresis loop measurement indicates that titanomagnetite of associated pseudo-single-domain/multi-domain grain sizes are responsible for the magnetic fabrics. Based on the clustering of the principal AMS axes, three types of AMS fabrics were recognized, (i) Normal fabric, interpreted as due to magma flow characterised by clustering of K 1 –K 2 axes on the dyke plane and K 3 axes are nearly perpendicular to it, (ii) Inverse fabric with K 2 –K 3 plane parallel to the dyke plane and K 3 is perpendicular to it and (iii) Intermediate fabric, with K 1 – K 3 axes clustering close to dyke plane. The inclination of the K 1 axis ( IK 1 ) of Normal fabric is the most important to determine the flow of magma for the studied dyke swarm. The IK 1 of the studied dykes were fed dominantly by horizontal ( IK 1