Current · Cross section

Cross-bedding (cross-stratification)

Sets of inclined layers within a bed. Trough cross-beds have concave-up, scoop-shaped sets; planar (tabular) sets have flat bounding surfaces.

How it forms

Migration of dunes (cross-bedding) or ripples (cross-lamination). Sediment moves up the gentle side of the bedform and avalanches down the steep side, so the inclined layers dip in the downcurrent direction.

Typical setting

Subaqueous dunes and sandbars, the shallow seafloor, desert dunes

Way up

Truncated at the top and tangential (curving into the base) at the bottom. Troughs are concave up. Truncation always happens up section.

Flow direction

Yes. Foresets dip downcurrent.

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