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.)