Magnetic anomalies over the Andaman Islands and their geological significance

The Andaman Islands form part of the outer-arc accretionary sedimentary complex belonging to the Andaman–Sumatra active subduction zone. The islands are characterized by thick cover of Neogene sediments along with exposed ophiolite rocks at few places. A regional magnetic survey was carried out for the first time over the Andaman Islands with a view to understand the correlation of anomaly signatures with surface geology of the islands. The residual total field magnetic anomaly maps have revealed distinct magnetic anomalies having intermediate to high amplitude magnetic signatures and correlate with the areas over/close to the exposed ophiolite rocks along the east coast of north, middle and the south Andaman Islands. The 2D modelling of magnetic anomalies along selected E–W profiles across the islands indicate that the ophiolite bodies extend to a depth of about 5–8 km and spatially correlate with the mapped fault/thrust zones

Effect of Fe doped and capping agent – Structural, optical, luminescence, and antibacterial activity of ZnO nanoparticles

Zinc oxide nanoparticles (ZnO NPs) are indispensable materials for spectral and optical phenomena, prepared by a chemical precipitation method. We studied their properties resulting from different dopants in the nanoscale. The samples' structure, texture, energy band, and photoluminescence were examined using XRD, TEM, FTIR, PL, and UV–VIS spectroscopy. XRD shows the single hexagonal Wurtzite with crystallite sizes from 10.1 to 17.8 nm and the spherical shape particles. The octahedral sites at 470–489 cm−1 and the tetrahedral sites at 616 cm−1 were observed in the FTIR studies. PL showed a wider bandgap, better UV emission, and decreased defect density of the Fe doped than that of the pristine one. Fe-doped ZnO NPs are more active than pristine ZnO NPs for their quenching or absorbing properties, indicating their antibiotic properties