Palaeomagnetic results of 19 dykes situated south of Narmada river (21030'N, 74015, E) in Dhule district of the Maharashtra state, India are reported. Of the 19 dykes, 1 I dykes exhibit a normal magnetic polarity, and 4 dykes a reverse polarity. The remaining 4 dykes yielded mostly scattered and unstable sample directions. The normal and reverse directions are almost antipodal. The characteristic remanence is indicated to reside in magnetite, and is most probably primary. The N-Pole position corresponding to the mean directions of l l dykes (7 normal and 4 reversed) based on a minimum of 4 sample characteristic directions per dyke is at 37.2°N, 80.5°W (A95=9.7°). This pole is concordant with the Deccan Superpole, indicating a similar age ofmagnetization for the Deccan basalt flows and the dykes intruding them. Ajoint consideration of similarity ofpalaeopoles of the dykes and the lava flows, magnetic polarity of dykes, and their stratigraphic positions of intrusions in the lava flow sequence support the view that the volcanic activity in the Deccan area spanned a short duration. The post-trappean tectonic activity resulting in the dyke swarms may possibly have coincided with the opening of the Arabian Sea and the rifting of the Seychelles-Mascarene oceanic plateau.
A palaeomagnetic study of 115 samples (328 specimens) from 22 sites of the Mid‐ to Upper Cretaceous Bagh Group underlying the Deccan Traps in the Man valley (22° 20′N, 75° 5′E) of the Narmada Basin is reported. A characteristic magnetization of dominantly reverse polarity has been isolated from the entire rock succession, whose depositional age is constrained within the Cretaceous Normal Superchron. Only a few samples in the uppermost strata have yielded either normal or mixed polarity directions. The overall mean of reverse magnetization is Dm=144°, Im=47° (α95=2.8°, k=152, N=18 sites) with the corresponding S‐pole position 28.7°S, 111.2°E (A95=3.1°) and a palaeolatitude of 28°S±3°. The characteristic remanence is carried dominantly by magnetite. Similar magnetizations of reverse polarity are also exhibited by Deccan basalt samples and a mafic dyke in the study area. This pole position falls near the Late Cretaceous segment of the Indian APWP and is concordant with poles reported from the Deccan basalt flows and dated DSDP cores (75–65 Ma) of the Indian Ocean. It is therefore concluded that the Bagh Group in the eastern part of the Narmada Basin has been pervasively remagnetized by the igneous activity of Deccan basalt effusion. This overprinted palaeomagnetic signature in the Bagh Group indicates a counter‐clockwise rotation by 13°±3° and a latitudinal drift northwards by 3°±3° of the Indian subcontinent during Deccan volcanism.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.