Pattern and genesis of lineaments in and across son-Narmada lineament zone in a part of central India around Renukoot, district Sonbhadra, U.P.

Abstract

Lineament studies are not only important for the interpretation of hidden architectures of the rocks but also can be applied to decipher the analysis of structural deformation patterns and tectonism of a region besides numerous other applications in the field of earth sciences. In central part of India, SonNarmada-Tapti (SONATA) is aprominent ENEWSW trending lineament zone which is bound by two major faults namely Son-Narmada South Fault (SNSF) and Son-Narmada-North Fault (SNNF), reaching upto Moho (Jain et a l . , 1995). The lineament zone extends about 1300 km from southern margin of Kathiawar peninsula in the west to the margins of the Vindhyan basin in the east. Throughout the geological history the zone has witnessed resurgent tectonism (Acharyya and Roy, 2000). According to Jain et al. (1995) and Acharyya and Roy (2000), there seems to have been no major post Vindhyan reactivation of SNNF, on the other hand, SNSF has witnessed protracted reactivation from Precambrian to Phanerozoic. In Precambrian rocks of the Son valley area lineaments have been observed in the Chhotanagpur Granite Gneiss Complex (CGGC), the Mahakoshal Group and the Vindhyan Supergroup (Semri and Kaimur Groups). The presence of lineaments in the Kaimur Group (Upper Vindhayan) attracted the attention of authors because the flat lying horizontally bedded sandstones of the Kaimur Group in the Son valley region are generally considered tectonically undeformed. Therefore, an attempt in the present work has been made to study the lineaments present in the southern part of Sonbhadra district Uttar Pradesh and adjoining regions of neighbouring states, where the Precambrian rocks of the Chhotanagpur Granite Gneiss Complex (CGGC), the Mahakoshal Group and the Semri and Kaimur Groups of Vindhyan Supergroup are exposed. The lineaments occurring across the SONATA zone of this region have been studied in context of their genesis. The study area (Fig. 1) is bound between latitudes 23 ~ 46' N to 24 ~ 42' N and longitudes 82 ~ 35' E to 83031' E forming parts of the Survey oflndia toposheet nos. 63L/14, L/15, L/16; 63 P/2, P/3, P/4, P/6, P/7, P/8; 641/13 and 64M/1 covering 7713 km 2 of area around Renukoot in the Sonbhadra district