Flaser bed

Flaser bedding, vertical section.

Flaser beds are a sedimentary, bi-directional, bedding pattern created when a sediment is exposed to intermittent flows, leading to alternating sand and mud layers. While flaser beds typically form in tidal environments, they can (rarely) form in fluvial conditions - on point bars or in ephemeral streams, or also in deep water environments when turbiditic sediments are reworked by seasonal bottom-currents.[1] Individual sand ripples are created, which are later infilled by mud during quieter flow periods.[1] These mud drapes are typically a minor constituent of the deposit; they can consolidate within three hours, protecting the underlying layer from erosion.[1] Flaser bedding typically forms in high-energy environments.[2][3]

In contrast to lenticular bedding which largely consists of mud relative to small amounts of sand, flaser bedding is dominated by sand with small amounts of mud interspersed.[citation needed]

References

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  1. ^ a b c Martin, A.J. (2000). "Flaser and wavy bedding in ephemeral streams: a modern and an ancient example". Sedimentary Geology. 136 (1–2): 1–5. Bibcode:2000SedG..136....1M. doi:10.1016/S0037-0738(00)00085-3.
  2. ^ Tom Bellile (2003-10-23). "Tidal deposits". (with photograph)
  3. ^ Reineck, H.E.; Wunderlich, F. (1968). "Classification And Origin Of Flaser And Lenticular Bedding". Sedimentology. 11 (1–2): 99–104. Bibcode:1968Sedim..11...99R. doi:10.1111/j.1365-3091.1968.tb00843.x.