Evidence of the deformation of dykes from the Central Deccan Volcanic Province, Aurangabad, Maharashtra, India

Abstract

AbstractThe Deccan Volcanic Province (DVP) covers an area of more than 500 000 km2. There are three major dyke swarms in this province, viz. the Narmada-Tapi, the Western Coast and the Pune-Nasik. In addition, the Nandurbar-Dhule and Pachmari dykes have also been studied. However, the Central Deccan Volcanic Province (CDVP), including parts of Aurangabad (Maharashtra, India), has received less attention than the SW, northern and NE parts of the Deccan Trap. We report on deformed/offset dykes in and around Aurangabad, in the CDVP. These dykes intrude the stratified host basaltic lava flows composed of weathered porphyritic and amygdaloidal basalt. This rheological contrast locally affected the emplacement of dykes, producing offset, the formation of sills, the curvature of dyke walls and finger-like intrusions. The offset of dykes is presumably caused by variations in local stress. The dyke swarm from the CDVP is reported for the first time. The range in the length and width of the dykes is 2.4–26.2 and 1–27 m, respectively. The dykes trend NE, which matches that of the Narmada-Tapi dyke swarm. The present study indicates that the feeder dyke(s) may have fed the basaltic lava flows of the Aurangabad region. The bent pipe vesicles indicate that the lava flowed towards the SE.