Neoproterozoic Tectonics of Northwest India: Insights from Field Evidence, Geochemistry, and Geochronology

The South Delhi Fold Belt (SDFB) is a Proterozoic fold belt trending NE-SW in northwest India. Its western boundary is defined by the crustal-scale Phulad Shear Zone (PSZ). To the west of the SDFB lies the Marwar Craton, and the timing of its amalgamation with the rest of India has been a subject of long debate. Scattered occurrences of ~1 Ga granites near the PSZ within the SDFB are temporally associated with the assembly of the Rodinia supercontinent. Our detailed field investigations reveal distinct pre-shearing deformation patterns in the SDFB and the Marwar Craton rocks. Geochemical and geochronological analyses of rocks from the SDFB and Marwar Craton indicate an extensional regime around ~1 Ga, with the collision and suturing of the Marwar Craton and SDFB occurring as late as 820 Ma. Our findings suggest that northwest India lacks geological evidence supporting the assembly of Rodinia, a critical insight for reconstructing Rodinia's paleogeography and clarifying India's role within the supercontinent.