Description

The fine-to-medium sandy sediments are the major component of facies association V, while the gravels barely exist (Figure 8A). They display bed with a succession of Sm, Sh, Si, and Fr. Massive bedding and parallel bedding can be recognized generally. Moreover, the overall sandstone body develops multi-cycle erosion surfaces with fining-upward. The ORCs are mainly mudstone (shale) breccias (Figure 8C,D,F,G,I), but rarely coaly fragments and plant pieces. The intact boulder ORC retains the horizontal bedding of shale (Figure 8C,G). These clasts are angular to sub-rounded, with the characteristic of imbricate arrangement. The long axis of the particles is generally parallel or sub-parallel to the bedding. On the surface of basal erosion, ORCs are accumulated in variable shape and size (small pebbles to boulders; Figure 8C,F,H). In the middle parts of the single sandstone body, long strip or flaky clasts are sporadically floating in structureless sandstone (Figure 8D,E,I,J). The finely rounded pebble ORCs are deposited in weak continuous parallel laminations at the upper parts (Figure 8B).

**Figure 8.** Sedimentary characteristics of the organic-rich clasts in the debris/turbidity flow (log LX-13). (**A**) Schematic sedimentary succession of the subaqueous debris/turbidity flow, occurring with high ORC content. (**B**–**J**) Photos of lithofacies and ORC types, noting the di fferences in the morphology and amounts of ORCs in di fferent lithofacies. ( **K**) Location of logA in the debris/turbidity flow schematic sedimentary model.
