Main Features | Type 1 | Type 2 | Type 3 |
Sst. Grain Size | Mainly fine-medium, occ. coarse (Channels) vf. to medium (Mouthbars) | Fine to coarse, occ. very coarse, pebble lags | Mainly coarse to very coarse with common scattered pebbles |
Cross-bedding | Mainly trough (Channels) | Mainly trough | Mainly planar tabular |
Mouthbar | Commonly well-developed, but occasionally limited | Absent or very limited, except in deep water deltas | Usually absent, but seen in some deep water deltas |
Planform | Narrow (c1km) channels, much wider mouthbars | Channel belts 8 - 50 km | Narrow (2 - 4 km) channels up to 70 km wide sheets |
Lateral accretion surfaces (Meandering) | Rare | Absent | Absent |
Palaeocurrent range | Highly variable | Narrow in channel, highly variable in different belts | Narrow |
Incision | None | Sometimes | Very common |
Position in cylothem | Early to Middle | Late | Very late (after eustatic min.) |