Precambrian Geotectonics in the Himalaya–Sans Cenozoic Hangover by B.K. Chakrabarti, Elsevier, 2023, 373p

This last chapter discusses the Precambrian geotectonics in the Himalaya and avoids any Cenozoic hangover like considering the nappe and klippe structures in the Lesser Himalayan Crystalline (LHC) as Himalayan products—these are Paleoproterozoic structures. As illustration on the Paleoproterozoic tectonic elements studied in the Shimla-Kinnaur area of the Himachal domain, the author describes various aspects of the terrain: deformation and metamorphism and mineral growth, a conspicuous mineral lineation (L1) of regional presence, etc. Study on some important rock types includes quartzite-mylonite rocks, quartz fabric and mylonite gneiss, metasedimentaries and granite-migmatite-gneiss, granitic rocks, and metabasic rocks. An interesting topic covers deformational and chemical growth pattern in syntectonic garnet of the metamorphites. Also, crystallinity of carbonaceous material and structural state of muscovite added new dimension to author's study! The author had confidence to comment on the absence of any evidence of overthrusting of the Jutoghs over the Chails and on age of regional metamorphism which was Paleoproterozoic. The entire exercise of the author was on the Paleoproterozoic tectonic picture of the Himalaya. He made a maiden attempt to make Paleoproterozoic regional correlation. The Main Central Thrust (MCT) is considered as a gap between the Paleoproterozoics and the Neoproterozoics—a decollement and unconformity zone, a most possible Main Central Thrust Zone during later tectonic impress. And the nappe and klippe in LHC are Paleoproterozoic products! Perhaps new work on evolution of the lofty Himalaya would not consider old structures as Tertiary products and would make less use of the in north-northeast–south-southwest tectonic sections specially when Precambrian scenario is in mind! And if Neoproterozoics are at all present with doubtful identity south of the MCT (new), we restrict their movement far and near to the south!