A coarse bioclastic limestone, containing identifiable fragments of crinoids (e.g. top centre) and a massive tabular coral colony (Favosites) in life position. The limestone is crudely bedded.
This cross section through part of unit P21 shows some in situ (in growth position) colonies of reef-building organisms.
- In between these colonies, there is much coarse broken-up (bioclastic) material consisting of fragments of the shells and skeletons of calcium carbonate-secreting organisms.
- What conclusions can you
draw about the environmental energy during the deposition of these limestones?
- Which of the organisms you studied in the lab were reef builders?
Scale: the picture is about 1 metre across
Grid reference: 904
286