On the basis of stratigraphic, tectonic, and metamorphic studies in certain critical Pre-Cambrian areas of Nagpur-Bhandara-Drug region and twenty-six K-Ar age data of representative samples, the authors have suggested a new generalized succession and correlation of the dated orogenic cycles and phases, and have drawn the following conclusions:-
(a) Amgaon cycle closed during the period 1444–1730 m.y.
(b) Sakoli cycle (I phase) closed at 1330 m.y., and during Sausar orogeny (864–996 m.y.) the north-western part of Sakoli syn-clinorium was deformed and metamorphosed (862–950 m.y.).
(c) Sausars and Sakolis, both post-Amgaon in age, were deposited in separate basins and had different tectonic histories.
(d) Nandgaon folding phase (< c. 1200 m.y.) affecting Bijli rhyolites is younger than Sakoli (I phase), and Chattisgarh Cuddapahs are younger than Khairagarh phase (< c. 600 m.y.).
(e) In Bastar area Bailadila cycle closed at c. 2100 m.y.