Unit: P19

image PAL-02

full-size image

The groove casts shown here are another example of bottom structures (i.e. those preserved on the undersides of beds). Fragments are dragged by a current over the underlying mud and the resulting grooves are then filled with sand deposited by the current. Both flute and groove casts are commonly produced by turbidity currents.
  • How did these structures form? Draw a sketch to show this.
  • Which direction was the current moving? (with structures such as these, there is not a unique answer - there are two possible directions, 180 degrees apart)

Scale: coin is 23 mm across

Grid reference: 979 305

Back To: [ Palaeozoic Rocks ]

This page is maintained by Roger Suthren

Last Modified: 18 November, 2008