Laboratory analysis of dissolution effects on Southern Ocean polycystine Radiolaria

• Southern Ocean dominant radiolarians more solution resistant than diatoms.
• Rate of radiolarian dissolution decreases with depth in Southern Ocean sediments.
• Dissolution variation among dominant Southern Ocean radiolarians is minor.

Laboratory analyses were conducted on siliceous microfauna in Holocene and older interglacial samples from the Southern Ocean to determine dissolution effects on their skeletons. Examination of siliceous skeletons was made at regular intervals throughout the experiment. No major differential dissolution was detected among the dominant Southern Ocean radiolarian species as only minor variations in relative abundance occurred with increasing degrees of silica dissolution. Dissolution rate is a function of age of the polycystine Radiolaria with higher Holocene rates than those registered in the interglacial sample. These results serve to strengthen the premise that information about past Southern Ocean conditions can be reliably acquired from analysis of polycystine radiolarian assemblages preserved in marine sediments.