Reply to the discussion of Deb (2013) on the paper of Saha et al. (2013) entitled ‘Tectono-magmatic evolution of the Mesoproterozoic Singhora basin, central India: Evidence for compressional tectonics from structural data, AMS study and geochemistry of ba

We appreciate that our attempt to document deformation pattern within the Mesoproterozoic Singhora Group, India, and to resolve some key stratigraphic issues in Chhattisgarh geology (Patranabis-Deb and Chaudhuri, 2008 and Dhang and Patranabis-Deb, 2012), in recent times, has attracted the attention of Deb. We whole heartedly welcome the keen interest shown by Deb in our paper and discussions attempted by him on different aspects of the paper. Here we offer our strong rebuttal of his imaginative discussions, principally because the claims made by Deb are neither supported by outcrop-based field data nor through any available subsurface geophysical data. It appears that the key concern of Deb (2013) was to force-fit the structural grains of the Sonakhan greenstone belt within the deformation pattern of Singhora cover sediments, upholding an unsubstantiated assumption that the Sonakhan greenstones belt constitutes the basement for the Singhora basin. Without citing any evidence (outcrop, geophysical or bore hole) showing Sonakhan metamorphics in the basement of the Singhora basin, he plotted the structural data of the Sonakhan Greenstone Belt and attempted comparison of those with the bedding attitudes of the Singhora cover sediments, and claimed that the possible rejuvenation of basement faults triggered folding in the Singhora cover sediments. Leaving aside the issues of lack of any field support, available geophysical results (3 layer gravity survey by Srinivas et al. (2000); magnetic survey by Srinivas et al. (2004)) and short borehole observations (pers. comm., Mukherjee, A., 2012) – all clearly demonstrates unclassified Archean/Paleoproterozoic granites and gneisses of the Bastar craton as basement for the Singhora Basin, not the Sonakhan Greenstones. Neither is the presence of any basin-scale fault inferred from the basement of the Singhora basin in any geophysical model. The result of magnetic survey along the Basna–Sohela transect carried out by Srinivas et al. (2004), which represents the Singhora basement in particular, clearly shows granites as immediate basement for the Singhora. As the very assumption of Deb (2013) i.e., that the Sonakhan represents the basement to the Singhora basin, does not stand either on his own field data or on any strong reasoning, we refrain from any further discussion on this topic. Instead, we frame our reply on the doubts raised by Deb (2013) on the mapping, field analysis and concepts used in our paper (Saha et al., 2013).