Knowra Cross-bedding Cross-bedding Cross-bedding is a sedimentary structure in which inclined layers form within larger beds as dunes, ripples, or other bedforms migrate and deposit sediment.
Bedform : A topographic feature on a sediment bed, such as a ripple or dune, shaped by flowing water or wind. Migrating bedforms create the inclined layers preserved as cross-bedding.
Paleocurrent analysis : The reconstruction of ancient water or wind flow directions from sedimentary structures and grain fabrics. Cross-bed foresets provide measurements of the direction in which bedforms migrated.
Stratification (geology) : The arrangement of sedimentary rocks into layers or beds with differing physical or compositional properties. Cross-bedding is a distinctive internal pattern within sedimentary stratification.
Desert dune : A wind-built accumulation of sand in an arid landscape. Its migrating slip faces preserve large sets of eolian cross-bedding.
Dune : A mound or ridge of sediment shaped and moved by wind or flowing water. Dunes generate large-scale cross-beds as their lee slopes accumulate sediment.
Sedimentary facies : A body of rock distinguished by its physical, chemical, or biological features and interpreted depositional conditions. Cross-bedding helps identify facies associated with rivers, deserts, deltas, and shallow seas.
Bedding plane : A surface separating adjacent sedimentary beds, commonly marking a change in deposition or a pause in sediment accumulation. Bedding planes bound larger beds that contain cross-bedded layers.
River bar : A sediment accumulation within a river channel, formed by flow-driven transport and deposition. Migrating dunes on bars leave cross-bedded channel deposits.
Ripple mark : A small ridge-and-trough pattern formed on a sediment surface by moving fluid or waves. Migrating ripples produce small-scale cross-bedding in sediment.
Fluvial depositional environment : The setting where rivers deposit sediment across channels, bars, and floodplains. Channel and bar deposits commonly preserve cross-bedding from migrating water-laid dunes.
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