Fig. 4: Siwalik conglomerate event beds and Kosi mega-fan core.

a Photographs of conglomerate bed C2. b Close-up of coarse pebbles floating in sandstone beneath conglomerate bed C2. c Conglomerate bed C1. Photographs (d) and (e) illustrate the thin gravel layers observed in Middle Siwalik sandstone. Photographs (f) and (g) show thin gravel layers observed in Kosi megafan core (core KS4 and KS3, respectively; Fig. 1). Dashed red lines in picture (a) and (b) highlight the erosive base of the conglomerate beds (C1 and C2).