SUBHORIZONTAL LAYERING IN THE LOWER CRUST AND ITS TECTONIC SIGNIFICANCE IN THE NARMADA-SON-REGION, INDIA

Comparison of deep seismic sounding (DSS) results of different profile s across the Narmada-Son Lineament (NSL); India indicates the anomalou s nature of the crust along the Ujjain-Mahan profile. Forward travel t ime and synthetic seismogram modeling, using normalized record section s of refraction and wide angle reflection data acquired along the Ujja in-Mahan deep seismic sounding profile across NSL, brings into focus t he presence of high velocity (7.0-7.3 km/s) subhorizontal layers From a depth of 8-12 km down to Moho. The tectonic implication of such refl ections (layering in the crust) is discussed. The two fault zones, rep orted by earlier workers, flanking the rift might have acted as Feeder s for the mantle material to intrude into the middle and lower crustal columns.