Description

The facies association III comprises Gm, Sm, Sr, Sh, Fl, Si, Fr, and C (Figure 6A). The sandstone body is developed in a multi-period, with a cumulative thickness of more than 15 m. Massive bedding, wavy bedding, and parallel bedding are main sedimentary structures. The GR logging curve is finger-shaped with some fluctuation (Figure 6A). The ORC in this facies association is characterized by variable size (granules to boulders; 2 to >256 mm) and shape, angular nature and plastic deformation. At the bottom parts of the single sand body, the clasts are disorderly accumulated with gravel or coarse sand matrix (Figure 6H). The floating clasts are isolated occurring in the structureless host sandstone, with strong deformation and long-axis running parallel to bed (Figure 6B,C,E–G,I,K). The small granule clasts are clustered in the form of wavy or parallel laminations (Figure 6J).

**Figure 6.** Sedimentary characteristics of the organic-rich clasts in the tidal channel (log LX-10). (**A**) Schematic sedimentary succession and the gamma-ray response of the tidal channel, including the positions of ORC. (**B**–**K**) Photos of typical lithofacies and ORC types in the tidal channel. (**L**) Schematic sedimentary model of barrier coast, showing the location of logA.
