Neckarstaden 14, D-6900 Heidelberg, W. Germany.
Stable isotope study of carbonate sediments from the Coorong Area, South Australia
Article first published online: 14 JUN 2006
Volume 31, Issue 6, pages 837–849, December 1984
How to Cite
BOTZ, R. W. and VON DER BORCH, C. C. (1984), Stable isotope study of carbonate sediments from the Coorong Area, South Australia. Sedimentology, 31: 837–849. doi: 10.1111/j.1365-3091.1984.tb00890.x
- Issue published online: 14 JUN 2006
- Article first published online: 14 JUN 2006
- received 15 December 1983 revision 24 March 1984
The mineralogy and isotope geochemistry of carbonate minerals in the Coorong area are determined by the water chemistry of different depositional environments ranging from seawater to evaporitically modified continental water. The different isotopic compositions of coexisting calcite and dolomite suggest that each of the above two minerals was formed from water of composition and origin unique to that specific mineral. In addition, the dolomite was not formed by simple solid state cation exchange.
The occurrence of two types of dolomite was shown by isotope analysis and SEM observations. The dolomite, which is isotopically light (δ13C = -1 to -2%0; δ18O=+3 to +5%0) and of fine grain size (˜ 0·5 μm) probably precipitated under the influence of evaporitically modified continental water. Coarser grained dolomite (up to 4 μm) is isotopically heavier (δ13C=+3 to +4%0; δ18O=+5 to + 6%0) contains Mg in excess of Ca and was formed in or close to equilibrium with atmospheric CO2 probably by the dolomitization of aragonite.