Despite comprising more than 60% of the sedimentary record, mudrocks have received disproportionately little study, both in terms of their sedimentology and diagenesis. This is perhaps surprising considering their economic importance as the source rock for most commercial hydrocarbons. To readdress this imbalance, a British Sedimentological Research Group/Petroleum Group meeting entitled ‘The Sedimentology and Diagenesis of Organic-Rich Sediments’ was held at Sheffield University on the 24–25 September 1987. The overall intentions of the meeting were: (a) that it should be interdisciplinary, (b) bring together research workers interested in diverse aspects of mudrock sedimentology and diagenesis (from both organic and inorganic backgrounds) and (c) to expand the generally sketchy mudrock data base.
With these aims in mind some 60 people gathered in Sheffield to hear two days of talks and examine a variety of posters dealing with topics that ranged from palaeoenviron-mental interpretation to inorganic geochemistry of mudrock sequences.
In a keynote address, I. N. McCave (Cambridge) presented a stimulating talk on mud deposition in modern environments. He particularly emphasized the important role of particulate organic matter as a clotting agent. He showed that the chemistry of this organic clotting agent influenced its ‘clotting ability’, and that, in turn, its chemistry was dependent on total oxygen concentrations in the water column. As a result he noted that the organic/inorganic ratio in mudrock sequences from different localities varied despite them having similar overall accumulation rates.
Continuing with aspects of mudrock deposition, P. B. Wignall (Birmingham) documented the importance of storm events in