Flute casts on the underside of a sandstone bed - a type of bottom structure. Flute casts are formed when the scouring action of a current erodes hollows in a previously deposited muddy layer. These hollows then fill with sand carried by the current. Flute casts are palaeocurrent indicators - the nodal (pointed) end of each is the upstream end, indicating that in this case the current flowed from left to right.
- How exactly did these structures form? Draw a sketch to show this.
Scale: coin is 21 mm across.
Grid reference: 979
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