(Table 1) Geochemistry at DSDP Hole 71-511

Transformation of aragonite to calcite and of high-magnesian to low-magnesian calcite is accompanied by a substantial increase in volume which produces cone-in-cone texture by tangential compression. Internal stresses stored within in the sediment could not be released until the core was extracted; then material and mounting medium expanded spontaneously.

B-isotope and Mg/Ca ratios of planktonic foraminifera from ODP Hole 108-668B and esimates of salinity, alkalinity and pCO2 (Table 1)

Knowledge of past atmospheric pCO2 is important for evaluating the role of greenhouse gases in climate forcing. Ice core records show the tight correlation between climate change and pCO2, but records are limited to the past ~900 kyr. We present surface ocean pH and pCO2 data, reconstructed from boron isotopes in planktonic foraminifera over two full glacial cycles (0-140 and 300-420 kyr). The data co-vary strongly with the Vostok pCO2-record and demonstrate that the coupling between surface ocean chemistry and the atmosphere is recorded in marine archives, allowing for quantitative estimation of atmospheric pCO2 beyond the reach of ice cores.