Flaser bed

{{Short description|Sedimentary bedding pattern}}

File:Flaser Bedding - geograph.org.uk - 938241.jpg

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.{{cite journal

| author = Martin, A.J.

| year = 2000

| title = Flaser and wavy bedding in ephemeral streams: a modern and an ancient example

| journal = Sedimentary Geology

| volume = 136

| issue = 1–2

| pages = 1–5

| doi = 10.1016/S0037-0738(00)00085-3

|bibcode = 2000SedG..136....1M }} Individual sand ripples are created, which are later infilled by mud during quieter flow periods. These mud drapes are typically a minor constituent of the deposit; they can consolidate within three hours, protecting the underlying layer from erosion. Flaser bedding typically forms in high-energy environments.{{cite web|title=Tidal deposits|url=http://www.uwm.edu/Course/geosci697/tidal/tidal-deposits.html|author=Tom Bellile |date=2003-10-23}} (with photograph){{cite journal

| author = Reineck, H.E.

|author2=Wunderlich, F.

| year = 1968

| title = Classification And Origin Of Flaser And Lenticular Bedding

| journal = Sedimentology

| volume = 11

| issue = 1–2

| pages = 99–104

| doi = 10.1111/j.1365-3091.1968.tb00843.x

|bibcode = 1968Sedim..11...99R }}

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.{{cn|date=September 2022}}