Actes du colloque organisé à Lyon les 28 et 29 novembre 1983, sous le patronage de la commission géographie de la mer du Comité National Français de Géographie. Une bibliographie internationale de 500 réf. a été réunie, ainsi qu'un index thématique
A l'issue du colloque sur le beach-rock, les participants ont élaboré la définition suivante: le beach-rock est une formation sédimentaire indurée sous l'effet d'une cimentation carbonatée, réalisée au niveau de l'étage médiolittoral. Il existe des
Beach-rocks, which are common in tropical regions, may be capped by coral reefs, or conversely develop upon reef flats, depending on the variations of sea level and coastal profile in recent times. Some good examples of these complex relationships
are presented here from the Northeastern coasts of Brazil where they are particularly conspicuous due to the thinness of coral formations and to the great development of the beach rocks.
The radiocarbon dating of a beach-rock from the Ligurian coast (Italy) has given an apparent 14 C age of 3330 95 yr B.P. In spite of the uncertainty on the actual age, the beach-rock seems to have been developing even after the Post-glacial climatic
optimum. Nine horary pH measurements have been done donc during 26 hours in 4 solution pits developed on the emerged beach-rock. High variations are observed. These observations are the same for each pit and this corroborates the importance of biochemical
The coast of Lebanon lends itself particulary well to the development of beach-rock, whatever the pluviometry, the nature of sediments, or the size of its constitutive elements. If the beach-rock does not appear in areas where the coastline