Step-Like Delta from Talchir Rocks Around Village Simlipal, Orissa

Within the Talchir Group of rocks of the Talchir Gondwana basin occurs a step-like delta around village Simlipal. The older of the two delta sequences is characterised by interference of topset and foreset beds, sleep foreset slope (10° - 26°) and imperceptible delta slope break. Irregular shifting of lake level during the growth of the older delta, possibly controlled by weather variation from abnormally high temperature condition to cold, cloudy and dry conditions resulted in the formation of step-like delta. Delta front collapsed due to decay of stagnant buried ice which formed part of the basement over which delta grew and gave rise to small scale fold, fault and stump features. Younger delta with a prominent well developed foreset forming a Gilbert type delta developed over the older delta under a stable lake level condition. Two delta sequences together fanned the complete sequence of step-like delta.