Aug 01, 2021 · Barrier markers formed as a result of screening by small gravels are discovered on the riverbed near this point (p6 in Fig. 13). The section at the survey point p7 consists of a sand body in the upper section with trough crossbedding and a gravel bed at the bottom, showing a positive rhythm overall from the bottom to the top (Figs. 2a and 12c).