Book excerpt: The metronomic variations of the Earth-Moon system and of the Earth-Sun orbital patterns produce gravitational and temperature effects that alter the physical environment on the Earth's surface. These give an interpenetrating effect of forcing cycles ranging from twice-daily tides, day-night alternations, various tidal patterns and the annual solar pattern. All of these have been used palaeontologically to give precision to short-term age determination in the past. It is cycles of the Milankovitch band that are showing promise of enabling new practical timescales to be established for parts of the geological record. These depend on changes in the Earth-Sun distance and changes in the tilt of the Earth's axis with respect to the Earth's orbit round the Sun. There is increasing evidence that small-scale sedimentary rhythmic couplets may represent the effect of such changes. The disentangling of the interpenetrating cycles to produce an orbital forcing timescale is an exciting problem and challenge for palaeobiology and sedimentology. These should enable numerical dates to be given to bio- and chronostratigraphical timescales and eventually enable many Earth processes to be analysed in real time. The papers in this volume represent major new developments in sedimentological, paIaeontological, geochemical and stratigraphical research being undertaken in this field.--Provided by publisher.--Provided by publisher.