The papers in this Special Publication arise from a discussion meeting, ‘Sea-level changes at active plate margins: processes and products’, sponsored by the International Association of Sedimentologists (IAS) and the Geological Society of London, and organized by the British Sedimentological Research Group (BSRG). The meeting was held in London in May 1989. Forty-seven papers and eleven posters were presented, of which 25 are published here. Only one paper in this volume (by Y. Saito) was not presented at the meeting.

The noun sediment comes to the English language from the Latin root sedimentum, meaning settling or sinking down,aform ofthe verb sedere,to sit orsettle. In earth and environmental sciences, sediment has a wide context that includes many forms of organic and mineral matter. In Part 1 we look more deeply at the origins of the sediment that occurs on and under the surface of the solid planets and which may be used to infer past environmental conditions and changes. Sediment accumulations may be grandly viewed as the great stratal archive of past surface environments, or more basically as‘dirt’. There has been sediment on the surface of the Earth since the Archaean, with the oldest known sediment grains dating from at least 4.4Ga (Part 1 Fig. 1). Sediment also mantles the surface of many other planets and their satellites, notably Mars, Venus and Saturn’s moon, Titan. <...>

Geochemistry has deep roots. Its beginnings can be traced back to antiquity, but many of the discoveries that are basic to the science were made between 1800 and 1910. The periodic table of elements was assembled, radioactivity was discovered, and the thermodynamics of heterogeneous systems was developed. The solar spectrum was used to determine the composition of the Sun. This information, together with chemical analyses of meteorites, provided an entry to a larger view of the universe.

In history and prehistory artefacts and structures are often concealed beneath the surface of the earth as a result of geological processes and perhaps more frequently as a result of human activity. A key aspect of landscape archaeology lies in the identification and interpretation of this hidden evidence or in the broader sense of the buried landscape.