Fold-Thrust Belt Architecture and Structural Evolution of the Northern Part of the Nallamalai Fold Belt, Cuddapah Basin, Andhra Pradesh, India

Cuddapah Basin, India: A Collage of Proterozoic Subbasins and Terranes

“…This problem will be best resolved, once the geometry of the folded NFB is appropriately documented and the lateral continuation of beds established across the folds and faults. Significant observations in this context are recorded by Meijerink et al (1984); Saha (2002Saha ( , 2004; Chetty (2011); Saha (2013, 2015) and Tripathy et al (2019).…”

“…Detailed mapping on a 1:25,000 scale in the northern part of the NFB, yielding significant evidence of its structural evolution concerning the Palnad subbasin. Tripathy et al (2019) were able to demonstrate that the folded Nallamalai Group of rocks are thrust over subhorizontal Kurnool sediments. The complex folding and imbricate thrust planes could be modeled by them, providing an insight into the thrust-sheet emplacement along the Maidukuru Thrust.…”

“…However, the deformed Nallamalai Group in the NFB (excluding the Srisailam Quartzite) is shown to be allochthonous, bounded by major thrusts changed to "Kadapa." (Tripathy et al, 2019) and advocated its exclusion from the Cuddapah Supergroup. This is reflected in Table 1 which enumerates the stratigraphy of this basin.…”

“…This exposure demonstrates that the Nallamalai Group must be younger than the Papaghni and Chitravati Groups. However, there is a need to reassess the contact between the three groups from the perspective of the Maidukuru Thrust and the observations regarding the equivalence of Gandikota Formation (e.g., Meijerink et al, 1984;Tripathy et al, 2019).…”

“…We, consider them to be contiguous crustal blocks. This suggests that the CB, NFB and NSB are a collage of terranes separated by tectonic contacts that have an interlinked evolutionary history spanning the Late Paleoproterozoic to Neoproterozoic times (Tripathy et al, 2019;Saha and Sain, 2019).…”