Crustal velocity structure along the Nagaur-Rian sector of the Aravalli fold belt, India, using reflection data

Deep reflection data was collected along the Nagaur-Nandsi profile, Rajasthan (across the Aravalli fold belt), India, to study the tectonic pattern and evolutionary history of the Northwestern Indian Shield. However, as there was no coincident wide-angle/refraction input/well data input, no velocity picture could be derived to supplement the reflection results. In the present study, as velocity information is very important for a realistic analysis of the reflection time sections, we have used the interval velocity derived from stack velocities (Hubral, P. and Krey, T., 1980. In: Larner, K.I. (Ed.), Interval Velocities from Seismic Reflection Time Measurements. SEG, Tulsa, OK), to arrive at a possible velocity-depth section, along the 90-km Nagaur-Rian sector. This was followed by dynamic forward modeling, using the interval velocity model as the starting model. The resultant velocity depth section has a four-layer structure. One of the layers (third) is a low-velocity layer. The lateral extension of this layer vis-à-vis with other layers is presented, for a better understanding of the structure and tectonics of the Aravalli-Delhi fold belt.