Current · Cross section, Top of a bed

Imbrication

Flat pebbles or cobbles overlapping like shingles.

How it forms

Clasts rolling along a channel base come to rest with their downstream end raised on the clast ahead, so they tilt against the flow.

Typical setting

Conglomerates: channel bedload, alluvial fans; also glacial and deltaic gravels

Way up

Not a way-up indicator

Flow direction

Yes, in channels clasts dip upstream. Glacial and deltaic gravels can differ, so know the setting.

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