Ice-water pits upon the Yellow River delta plain

The erosion (circular) pit is a common sedimentary structure but its genesis is complex. Many erosion pits occur on the Yellow River delta plain, with some formed by ice-water erosion. The ice-water pits are generally circular or semi-circular in cross-section, and are typically 2–40 cm across and 2–20 cm in depth. We identify four types of pits on the basis of their origin: (i) pits that formed by liquefaction and tight arrangement, (ii) pits that formed by spattering, (iii) pits that formed by lateral leakage and (iv) pits that formed by bottom leakage.The formation of the ice-water pits is likely a function of many complex variables including frequent runoff, channel structure, ice run and fine sediment size. The example of ice-water pits from the Yellow River delta plain offers a useful frame of reference for the interpretation of formation conditions and environment significances of some circular pits (pot or pothole) in ancient rocks.