Relative sea-level rise and neotectonic events during the last 6500 yr on the southern eastern Rhone delta, France

The analysis of peat formations from the eastern limit of the Rhone delta a llows us to follow relative sea-level changes over the last 6300 yr. The cu rve represents two periods of rapid relative sea-level rise (about 2 mm/yr) , the first, between 6295 +/- 50 and 4585 +/- 45 BP, and then the second, b etween 2120 +/- 55 and 1200 +/- 55 BP. These two periods are separated by a period of stability between 4085 +/- 60 and 3520 +/- 55 BP. The comparison with data from the rocky coast to the east of Marseille indicates a negati ve difference of between 1.5 and 0.5 m, then rapid adjustment after 2120 +/ - 55 BP, The existence of an incompressible substrate, along with the thinn ing-out of the Holocene deposits along the limits of the deltas, restricted the effects of subsidence and compaction. We prefer the hypothesis that te cto-subsident movements account for these differences, as well as the rapid rise in relative sea-level during this second period. This is compatible w ith the network of post-miocene faults that account for the differences in altitude of the Roman quarries carved-out from the miocene layers. (C) 2000 Elsevier Science B.V. All rights reserved.