DECCAN VOLCANIC OF MALWA, STRATIGRAPHY AND CORRELATION OF BASALTIC LAVA FLOWS USING MEGACRYST BEARING HORIZON AS TOOL, PARTS OF WESTERN M.P. INDIA

A review of earlier studies the Deccan Trap occurrences parts Ratlam, Mandsaur, Jhabua, Dhar, Khargone, Indore, Ujjain and Shajapur districts Madhya Pradesh, India was carried out area falling between latitudes 220 0000 to 2400000N longitudes 7400000 7600000 in Survey Quadrangle sheet Nos. 46I, 46J, 46M 46N.The main objectives study were synthesize data on basaltic lava flows , their types ,their diagnostic characteristics with special emphasis delineating identifying various megacryst horizons levels specific elevation above m.s.l. build up litho-stratigraphy for regional correlation. Broadly exhibits Proterozoic Aravalli Supergroup, Cretaceous, Bagh Lameta Groups intruded dykes sills. The Supergroup is represented by Udaipur, Lunavada Champaner Groups. Udaipur Group consists mainly hornblende gneiss, marble calc-silicate, carbonaceous phyllites chlorite schist. comprises dolomitic limestone (Phosphate bearing), quartzite, muscovite quartz schist, feldspathised gneissic feldspathic rock biotitic gneiss. dolomite, phyllite, slates basic intrusives. Super group rocks also serpentinite, pyroxinite, granite rocks. unconformably overlain Cretaceous marine sedimentary deposits Group. It includes Lower arenaceous Upper calcareous units occurs as discontinuous outcrops. These are almost horizontally sub disposed. three / Formations i.e. Nimar sandstone nodular subsequently coralline limestone. noticed east South East exposures, overlying sandstones. predominantly consist limestone, gritty conglomerate generally exhibit hummocky topography sometimes display solution channels. mostly sub-horizontally disposed an average thickness 5- 6 m. has occupied a very long stretch which sequence 121 cumulative about 610 represent cyclic eruptions fine medium grained aphyric sparsely moderately highly mega porphyritic lava. About two third total Aa characters rest compound simple Pahoehoe. Some these containing feldspar laths varying size round five cm. have been identified at different elevations Quadrangles J, M, N basis horizons, grouped into six nomenclatures stratigraphic status. formations order antiquity 1) Mandleshwar formation, 2) Choral formation,3) Dhar 4) Indore Formation 5) Bargonda 6) Singarchori Formation. Full exposed only quadrangle 46N whereas M do not Formations. An attempt made correlate degree sheets 46 I, surroundings Geological Quadrangles. Megacryst bearing lava- act marker this purpose. large number dyke swamps well doleritic compositions marked around Narmada River. intensity more oldest it gradually decreases increasing towards younger general trend varies from North – West E-W running parallel lineament, besides few cut across lineament oriented along NNW-SSE N-S direction. Length 200 m 20 Km width meters much possibility exists that may actually feeders through periodic tholiitic took place resulting formation such thick pile flows. Besides many seven Intertrapean fossiliferous recognized within basal part demonstrate episodic nature volcanic activity, periods quiescence resilience. overall flow s interrelations relative dispositions thinning /swelling pinching nature. Their elevations, occurrence units, change characters, gradient relation preexisting slope elements reveals sources Older situated somewhere west south those Younger located Eastern Mhow studied.