Calcite saturation and dissolution index of core-top sediment samples from the Ontong Java Plateau, Mid-Atlantic Ridge, the Caribbean and the Ceara Rise, the Indian Ocean, the Ninety-East Ridge and from the east of Madagascar ...

• Main Authors: Johnstone, Heather J H, Schulz, Michael, Barker, Stephen, Elderfield, Henry
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 2010
• Subjects: Giant box corer; MultiCorer; Box corer; Piston corer; M16/2; M38/2; M35/1; MW9109; RC14; V29; CD129; Meteor 1986; Moana Wave; Robert Conrad; Vema; Charles Darwin; Center for Marine Environmental Sciences MARUM; Planktonic foraminifera
• Online Access: https://dx.doi.org/10.1594/pangaea.756133; https://doi.pangaea.de/10.1594/PANGAEA.756133

X-ray computed tomography (CT) provides an insight into the progression of dissolution in the tests of planktonic foraminifera. Four species of foraminifera (G. ruber [white], G. sacculifer, N. dutertrei and P. obliquiloculata) from Pacific, Atlantic and Indian Ocean core-top samples were examined by CT and SEM. Inner chamber walls began to dissolve at Delta[CO3**2-] values of 12-14 µmol/kg. Close to the calcite saturation horizon, dissolution and precipitation of calcite may occur simultaneously. Inner calcite of G. sacculifer, N. dutertrei and P. obliquiloculata from such sites appeared altered or replaced, whereas outer crust calcite was dense with no pores. Unlike the other species, there was no distinction between inner and outer calcite in CT scans of G. ruber. Empty calcite crusts of N. dutertrei and P. obliquiloculata were most resistant to dissolution and were present in samples where Delta[CO3**2-] ~ -20 µmol/kg. Five stages of preservation were identified in CT scans, and an empirical dissolution ... : Supplement to: Johnstone, Heather J H; Schulz, Michael; Barker, Stephen; Elderfield, Henry (2010): Inside story: An X-ray computed tomography method for assessing dissolution in the tests of planktonic foraminifera. Marine Micropaleontology, 77(1-2), 58-70 ...