Bioturbation effects on abrupt climatic changes recorded in deep sea sediments. correlation between profiles and accelerator $^{14}$C dating

International audience; Major trends of Quaternary global climate are reflected inthe continental ice volume changes which have been reconstructed by oxygen isotope analysis. $\delta^{18}O$ records from deep sea sediments show that the net glacial build-Up occurs relatively slowly, but that the end ofan ice age occurs quickly, in less than 10,000 yr, implying a non-linear response to simple Milankovitch theory. In order to understand the details of the last deglaciation a precise chronology of the paleoclimatic signals is needed. Carbon-14 measurements, performed by accelerator mass spectrometry, provide reliable ages on different species of foraminifera and can be used to provide a time scale for the oxygen isotope record. In addition, a bioturbation model has been used to point out the artifacts which could be falsely interpreted in terms of lead and lag in the paleoclimatic record. A comparison of the data with the restored signals enables the construction of a new deglaciation curve