Unit M24

image M24-04


Click to load full-size image

The tube-like structures in this sandstone are the sand-filled burrows of invertebrate animals which lived in the sediment beneath the sea floor. This process of churning of the sediment by burrowing organisms is bioturbation.If it is extensive, as here, it may obliterate original depositional structures, such as bedding.

  • What does the presence of burrows tell us about oxygen levels in the sediment shortly after the time of deposition?
  • What are the possible advantages for animals to live within the sediment rather than on the sea floor?

Scale: the pen is about 13 cm long.

Grid reference: 986 310

Back To: [ Mesozoic Rocks ]