Current · Cross section

Graded bedding

A bed that fines upward, from coarse grains at the base to fine grains at the top.

How it forms

Grains settle out progressively as a sudden, sediment-laden flow wanes, such as a turbidity current or storm.

Typical setting

Turbidites (deep marine fans), storm beds

Way up

Coarse at the base, fine at the top. Use with care: reverse grading occurs in debris flows and some alluvial fans, so rely on it only when seen repeatedly.

Flow direction

No.

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