Description

This facies association is built up of Sm, Sr, Si, Fl, and C (Figure 5A). The thickness of Sm and Sr ranges between 1 and 3 m. Sandstones have an upward-coarsening trend with sharp contacts at the bottom, as well as a finger-shaped logging curve (Figure 5A). Massive bedding, wavy bedding, and lenticular bedding can be observed. Also, roots can be recognized in the mudstone (Figure 5B,D,F,H,I). The ORC in facies association II is generally subrounded, which range in size between granule and pebble (2~64 mm; Figure 5I). The scattered clasts distribute in the massive host sandstone (Sm; Figure 5H,I). In the upper parts, wavy lamina or thin intercalated aggregates of granule ORC are often observed (Figure 5B,C).

**Figure 5.** Sedimentary characteristics of the organic-rich clasts in the crevasse splay (log SM-8). ( **A**) Schematic sedimentary succession and natural gamma-ray curve response of crevasse splay, showing the positions of di fferent types of ORC. (**B**–**I**) Typical photographs of lithofacies and ORC types in the crevasse splay, including some typical sedimentary structures. (**J**) The location of logA in the fluvial sedimentary model.
