A CRITIAL ANALYSIS OF IMPRINTS OF NEOTECTONISAM IN SUKTA SUB -BASIN, PARTS OF NARMADA RIFT VALLEY, DISTRICT KHANDWA M.P.INDIA.

The geological geomorphological and Neotectonic studies of parts of Khandwa district Madhya Pradesh were carried out with the aid of Air photos between latitude 21?30?00 to 21?45?00 and longilude 76?15?00 to 76?30? in parts of Survey of India Sheet No. 55C\6 and an area about 720 sq.km. was covered by photo interpretation. eologically the area comprised of Deccan trap and Quaternary sediment. The Deccan trap complex comprised of fifteen basaltic lava flows between 250 to 600 m above m.s.l. These lava flows constitute two formations viz. Khandwa formation (Nimar Group) consisting of six lava sheets between elevation of 250 to 360 m above m.s.l. and Asirgarh formation (Satpura Group) Consisting of nine lava sheets between 360 to 600 m above m.s.l. The exposed thickness of these lava flows is about 190 m. The Quaternary deposits are represented by the sediments of two domain viz the sediments of present domain of Sukta and sediments of paleo domain of Sukta. These sediment predominantly comprised of sand, clay, silt and rock gravel. These deposits in the area are viz thin and occur as relict terraces and flood plain deposits, the average exposed thickness is about 3 m. Geomorphologically the area comprised of nine surfaces each surface is characterized by distinct morphogenetic expression elevation, drainage, pedogenetic characters, slope elements and land use pattern. These surfaces are confined between 280 to 480 m above m.s.l. These surfaces in increasing antiquity are Quaternary terraces (280 to 300 m), Mordar surface (300 m), Sarala surface (320 m), Khadar surface (340 m), Borgaon surface (360 m), Jalandhar surface (400 m), Sarai surface (440 m), Gularpani (SE) 460 m and Gularpani (SW) (460-80 m). The morphogenetic expression of these surface has been appreciably by defaced by Neo-seismic events occurred in recent past along the network of lineaments traversing the area. The Sukta lineament trending in NE-SW, direction traverse across Mardar, Sarala, Khodar, Borgaon surfaces display selective entrustment and bear the imprints of Neotectonism in the area. The other geomorphic features and land form elements association with the area are flood plain point bar, low level terraces, channel braids. Linear scarp, curvilinear scarp, knee shaped band, scree, re-treating scarp and relict terraces. Besides the area is associated with the morpho-tectonic elements viz perennial channel segments, impersistent and partly internal drainage, knee shaped channel band, linear scarps and rock cut terraces. The study revealed the presence of five major lineament pattern in the area viz i) NE-SW, ii) NW-SE, iii) NNE-SSW to N-S, iv) NNW-WSW to E-W. The relative percentage of occurrence of these linear elements in different pattern is 29.7%, 23.4%, 23.4%, 14.1% and 9.4% respectively. The analysis of relative intensely of these lineaments reveal that major, intermediate lineament exhibit anisotropic intensity and minor elements isotropic intensity. The Sukta is the major stream which drains across the northern part of area. Its course is controlled by NE-SW trending lineament named as Sukta lineament. It appears to be basement lineament and some movement has been taken place along this lineament in recent past. It is evident by morphogenetic manifestation of the area and imprints of Neotectonism along this lineament. A another prominent lineament which traverses between Sultanpur and Bodgaon along Moti Nala, display occurrences of hanging and impersistent drainage which often truncate against this lineament. It indicates the readjustment of base level of drainage system perhaps due to recent movement along the NE-SW trending liniment in the area. The imprints and signature of such events are documented by these first and second order steams being their sensitive and infant nature and their quick response to such events. The Lakhauri NW-SE trending lineament and associated fabrics bears the imprints of Neotectonism and indicate some movement in the area. The other lineament trending in NNW-SSE to N-S, NNE ?SSE to N-S are associated with master joints and fracture and devoid of any significant signature of Neotectonic activity. The ENE ?WSW to E-W in the area represent 9.4%of total lineament density of the area and bears some imprints of neotectonic activity east of Arud The study of morphogenetic expression and analysis of imprints of neaotectonisam and overall morpho- tectonic manifestation of the area coupled with available data indicate that NE-SW trending set of lineament are active and some movement has been taken place in recent past in the area , as such the area appears to be active and prone to Neo-seismic movements. The critical analysis of data and application of keys combined with stratigraphic studies provide significant information to constrain timing and intensity and degree of movement of Sukta fault as inbuilt component of SONATA Lineament in the central western Narmada valley an important ENE?WSW-trending tectonic element responsible for the current interpolate seismicity being experienced in the central part of the Indian plate. The tectonic movements along the NSF during Late Pleistocene and Holocene have resulted three river terraces (NT_1 to NT_3) in Narmada valley which are in conformity of three major phases of tectonic movements in a compressive stress regimes recorded along the NSF: slow synsedimentary subsidence of the basin during Late Pleistocene due to differential movement, followed by inversion of the basin during the Holocene marked by differential uplift along the NSF. The study suggests that the inversion of the basin is in response to the significant increase in the intensity of compressive stresses in the Indian plate mainly during the Early Holocene. The occurrences of geomorphic land form elements and features, rock cut terraces , linear, scarp curvilinear scrap knee shaped channel band ad segments , perennial channel segments, impersistent and partly internal drainage, and rock scar and plantation surfaces which are the resultant elements of tectonic movement related NSF fault to wards lat Holocene . The present incisive drainage and recent seismic activity along Sukta lineament indicate that the compressive stresses continue to accumulate along the NSF due to continued northward movement of the Indian plate.