Gutter Marks Geology

Bedding plane exposures are common.

Gutter marks geology.

Field work was carried out on a four meter thick sequence of unfossiliferous silurian tymochtee dolomite along the southeastern margin of the silurian michigan basin. The studied section contains a swale gutter marks scour marks anhydrite molds raindrop impressions flat pebble conglomerate and ripple marks. The size and shape of these linear features resemble those of gutter casts of sand protruding into shale in other deposits. Pot casts and gutter casts are described for the first time in the lower part of the majanillos formation a middle triassic carbonate unit located in the external zones of the betic cordillera southern spain.

Two thin sandstone and siltstone horizons in the middle lias lower jurassic of the yorkshire coast informally called the lower and upper striped beds are characterised by small scale fining upward layers associated with filled scour channels gutter marks. Hampson and others published characterisation of gutter casts and thin sandstone bed connectivity in wave dominated deltaic reservoirs find read and cite all the. The term gutter marks applies to the initial troughs cut into the muddy floor of the depositional basin but these original structures like flute and groove marks are unlikely to be preserved. Scour marks and flute casts are scours dug into soft fine sediment which typically get filled by an overlying bed hence the name cast.

A dictionary of earth sciences. The term gutter cast was coined by whitaker 1973 for elongate downward bulging deep narrow erosional structures on the base of sandstone beds. The gutters are up to 5 m long 50 500 mm wide and up to 200 mm deep and have variable cross sections. Measuring the long axis of the flute cast gives the direction of flow with the tapered end pointing toward the flow and the steep end up current.

The gutter is a linear to sinuous u shaped depression up to 10 cm wide and of similar depth to its width formed by fluid scour from helical vortices travelling parallel to the flow direction.