The Holocene sedimentation rates in the Lower Segura Basin (eastern Betic Cordillera, Spain) : eustatic implications

By studying 36 boreholes in the Lower Segura Basin (eastern Betic Cordiller a) we identified a stratigraphic unconformity at an average depth of 30 m. The most recent sedimentary unit filling the basin, consisting of fluvial f lood plain and coastal deposits, lies on this unconformity. The age of the unit was established on the basis of 30 absolute C-14 datings, which indica te that the uppermost 20 m were deposited from 8,000 yr B.P. to the present . The estimated sedimentation rates range from 3.7 mm/yr for the period 8,0 00-6.000 yr B.P. and 1.9 mm/yr between 6,000 yr B.P. and the present. The f irst interval represents an episode of high sedimentary aggradation, interp reted in a context of rapid sea-level rise, whereas the second is character istic of relatively low aggradation related to sea-level stabilization.