REEVALUATION OF THE HOLOCENE SEA-LEVEL MAXIMA FOR THE STATE OF PARANA, BRAZIL

The best defined relative sea-level curves for the Brazilian coast, such as the Salvador (State of Bahia) curve, exhibit three Holocene maxima with progressively decreasing heights dated at about 5100, 3600 and 2500 years B.P. Although the maximum reached a height of 3 to 5 m in different sectors of the Brazilian coast, previous workers (Martin et al., 1988) postulated that for the coast of Parana State (Southern Brazil) it would have been less than 2.5 m and that the other maxima would likewise also have been lower than in other sectors. Re-evaluation of available evidence, including new data on Vermetidae, indicated an ancient sea level of 2.9+/-0.5 m above the present at 3500+/-60 years B.P., approximately coincidental with the second Holocene maximum in Parana. If the relative differences in height between the maxima that are observed elsewhere along the Brazilian coast hold for the Parana coast as well, then it is possible that the first maximum may have been 4 m above the present sea-level in this state. Consequently, great changes must be made in the distinction between the Pleistocene and Holocene coastal palaeogeography of Parana. Moreover, if the difference in height of the first maximum along the Brazilian coast must now be reduced from 2.5 m to less than 1 m, the prevailing hypothesis attributing the larger value to a migrating geoidal depression during the past 5000 years must be modified or even called into question.