Andaman Accretionary Prism:A Probable Locale for Different Mineral Deposit Types

Crustal growth and stabilization in the Andaman accretionary prism (AAP) occur via accretion of allochthonous crust, fragments of oceanic plateaus, and dismembered juvenile arc and ophiolite sequences. Multiple sutures developed in the AAP, as evidenced from multibeam, magnetic and seismic studies, are envisaged as the first-order structures that determine its distinct metallogenic signature. Furthermore, development of Andaman Back Arc Spreading Centre (ABSC) is attributed to a change from compression to more transgression stress regime as the AAP evolves. This stress regime change generates the first-order conduits for episodes of extensive metalliferous fluid flow via the pathways created by significant lateral displacements along the terrane-bounding multiple sutures. Hence, like many other accretionary orogens, complex association between subduction of the Indian plate and associated accretion, deformation, crustal thickening and melting, metamorphism, burial and exhumation may result in a wide variety of magma types, metal source regions and hydrothermal conduits. In conclusion, the expected deposit types in the AAP are volcanogenic massive sulphide deposits, seafloor massive sulphide deposits, rare earth elements and yittrium deposits and podiform chormite deposits.