Carbonates and Evaporites

, Volume 10, Issue 1, pp 114–123 | Cite as

Faunal relationship to grain-size, mineralogy and geochemistry in recent temperate shelf carbonates, western Tasmania, Australia

  • C. Prasada Rao
  • Zahra Z. Amini


In western Tasmania cool temperate shelf carbonates predominate over siliciclastics and contain mainly bryozoan-molluscaforaminifera assemblages with minor algae, echinoderms, worm tubes, sponge spicules and ostracodes. Skeletons are mainly in gravel to sand fractions and minor in silt-clay fractions. Bryozoans are the main constituent in sand to gravel-size, foraminifera are the main constituent in fine sand-size and molluscans are mainly in the gravel-size fraction. Echinoderms and algae are in sand fraction, whereas sponge spicules occur in fine to very fine sand fractions.

X-ray analysis of Tasmanian bulk sediments indicate that calcite (high-Mg to low-Mg calcite; mean 69%) and quartz (mean 22%) are the major minerals with minor aragonite content (mean 9%). Mg, Sr, and Na contents in bulk sediments are positively related to high-Mg calcite bryozoans. Sr and Na contents exceed abiotic calcite values due to biotic source of these elements. Compared to tropical bryozoans, the higher Sr contents in Tasmanian bryozoans indicate a higher rate of bryozoan skeletal formation in temperate waters. Mn and Fe contents of bulk sediments are closely correlated with r2 value of 0.85. These elements are derived mainly from terrigenous source and were incorporated into calcite in a dysaerobic marine environment.

Tasmanian temperate bryozoan faunal assemblages differ from tropical chlorozoan assemblages due to variation in seawater temperatures. Bryozoans break down into fragments and are redistributed mainly as gravel to sand-size grains by currents. Normal salinity of seawater (34–35%) and nutrients in temperate waters allow abundant growth of fauna. Mixing of water masses maintain sufficent saturation of CaCO3 and thus preserve temperate carbonates.


Calcite Sponge Bivalve Foraminifera Aragonite 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. ALEXANDERSSON, E.T., 1978, Destructive diagenesis of carbonate sediments in the eastern Skagerrak, North Sea:Geology, 6, p. 324–327.CrossRefGoogle Scholar
  2. BONE, Y. and JAMES, N.P., 1993, Bryozoans as carbonate sediment producers on the cool-water Lacepede Shelf, southern Australia:Sedimentary Geology, v. 86, p. 247–271.CrossRefGoogle Scholar
  3. BRAND, U. and VEIZER, J., 1980, Chemical diagenesis of a multicomponent carbonate system. I. Trace elements:Journal of Sedimentary Petrology, v. 50, p. 1219–1236.Google Scholar
  4. BROOKFIELD, M.E., 1988, A mid-Ordovician temperate carbonate shelf — the Black River and Trenton Limestone Groups of southern Ontario, Canada:Sedimentary Geology, v. 60, p. 137–153.CrossRefGoogle Scholar
  5. BURTON, E.A. and WALTER, L.M., 1991, The effects of PCO2 and temperature on magnesium incorporation in calcite in seawater and MgCl2−CaCl2 solutions:Geochemica et Cosmochimica Acta, v. 55, p. 777–785.CrossRefGoogle Scholar
  6. CARPENTER, S.J. and LOHMANN, K.C., 1992, Sr/Mg ratios of modern marine calcite: Empirical indicators of ocean chemistry and precipitation rate:Geochemica et Cosmochimica Acta, v. 56, p. 1837–1849.CrossRefGoogle Scholar
  7. CONOLLY, J.R. and VON DER BORCH, 1967, Sedimentation and physiography of the sea floor south of Australia:Sedimentary Geology, v. 1, p. 181–220.CrossRefGoogle Scholar
  8. Davies, P.J. and Marshall, J.F., 1973, BMR marine geology cruise in Bass Strait and Tasmanian waters — February to May, 1973. Bur. Miner. Resour. Australia, Rec. 134, 19 p.Google Scholar
  9. DRAPER, J.J., 1988, Permian limestone in the southeastern Bowen Basin, Queensland:Sedimentary Geology, v. 72, p. 155–162.CrossRefGoogle Scholar
  10. EDWARDS, R.J., 1979, Tasman and Coral sea ten year mean temperature and salinity fields, 1967–1976: Commonwealth Scientific and Industrial Research Organization, Division of Fisheries and Oceanography, Report no. 88, 4 p.Google Scholar
  11. HARRIS, G.P., NILSSON, C., CLEMENTSON, L. and THOMAS, D., 1987, The water masses of the east coast of Tasmania: seasonal and interannual variability and influence of phytoplankton biomass and productivity:Australian Journal Marine Fresh Research, v. 38, p. 569–590.CrossRefGoogle Scholar
  12. JAMES, N.P., and BONE, Y., 1989. Petrogenesis of Cenozoic temperate water calcarenites, South Australia:Journal of Sedimentary Petrology, v. 59, p. 191–203.Google Scholar
  13. JAMES, N.P. and BONE, Y., 1992, Synsedimentary cemented calcarenite layers in Oligo-Miocene cool-water shelf limestones, Eucla Platform, South Australia:Journal of Sedimentary Petrology, v. 62, p. 860–872.CrossRefGoogle Scholar
  14. KOLESAR, P.T., 1978. Magnesium in calcite from a coralline alga:Journal of Sedimentary Petrology, v. 48, p. 815–820.Google Scholar
  15. LEES, A., 1975. Possible influence of salinity and temperature on modern shelf carbonate sedimentation:Marine Geology, v. 19, p. 159–198.CrossRefGoogle Scholar
  16. MORSE, J.W., and MACKENZIE, F.T., 1990, Geochemistry of Sedimentary Carbonates, Developments in Sedimentology 48, Elsevier, 707 p.Google Scholar
  17. MUCCI, A. 1987. Influence of temperature on the composition of magnesian calcite overgrowths precipitated from seawater:Geochemica et Cosmochimica Acta, v. 47, p. 1977–1984.CrossRefGoogle Scholar
  18. NELSON, C.S., 1978, Temperate shelf carbonate sediments in the Cenozoic of New Zealand:Sedimentology, v. 25, p. 737–771.CrossRefGoogle Scholar
  19. NELSON, C.S., 1988. An introductory perspective, on non-tropical shelf carbonates:Sedimentary Geology, v. 60, p. 3–12.CrossRefGoogle Scholar
  20. NEWELL, B.S., 1961, Hydrology of SE Australian waters: Bass Strait and New South Wales Tuna Fishing Area. CSIRO Div. Fish. Oceanogr. Tech. Pap. 10, 20 p.Google Scholar
  21. PURSER, B.H., and SEIBOLD, E., 1973, The principal environmental factors influencing Holocene sedimentation and diagenesis in the Persian Gulf,in Purser, B.H. (editor), The Persian Gulf, Springer-Verlag, New York, p. 1–9.CrossRefGoogle Scholar
  22. RAO, C.P., 1981a, Cementation in cold-water bryozoan sand, Tasmania, Australia:Marine Geology, v. 40 p. M23-M33.CrossRefGoogle Scholar
  23. RAO, C.P., 1981b, Criteria for recognition of cold-water carbonate sedimentation: Berriedale Limestone (Lower Permian), Tasmania, Australia:Journal of Sedimentary Petrology, v. 51, p. 491–506.Google Scholar
  24. RAO, C.P., 1986, Geochemistry of temperate-water carbonates, Tasmania, Australia:Marine Geology, v. 71, p. 363–370.CrossRefGoogle Scholar
  25. RAO, C.P., 1988a, Paleoclimate of some Permo-Triassic carbonates of Malaysia:Sedimentary Geology, v. 53, p. 117–129.Google Scholar
  26. RAO, C.P., 1990a, Geochemical characteristics of cool-temperate carbonates, Tasmania, Australia:Carbonates and Evaporites, v. 5, p. 209–221.CrossRefGoogle Scholar
  27. RAO, C.P., 1990b, Petrography, trace elements and oxygen and carbon isotopes of Gordon Group carbonates (Ordovician). Florentine Valley, Tasmania, Australia:Sedimentary Geology, v. 66, p. 83–97.CrossRefGoogle Scholar
  28. RAO, C.P., 1993a, Carbonate minerals, oxygen and carbon isotopes in modern temperate bryozoa, eastern Tasmania, Australia:Sedimentary Geology, v. 88, p. 123–135.CrossRefGoogle Scholar
  29. RAO, C.P., 1993b, Mixing water masses: The key in understanding the origin of temperate carbonates. Australian Marine Geoscience Workshop Abstracts, p. 50.Google Scholar
  30. RAO, C.P., 1994a, Implications of isotopic fractionation and temperature on rate of formation of temperate shelf carbonates, eastern Tasmania, Australia:Carbonates and Evaporites, v. 9, p. 33–41.CrossRefGoogle Scholar
  31. RAO, C.P. and GREEN, D.C., 1983, Oxygen- and carbonisotope composition of cold shallow- marine carbonates of Tasmania, Australia:Marine Geology, v. 53, p. 117–129.CrossRefGoogle Scholar
  32. RAO, C.P. and ADABI, M.H., 1992, Carbonate minerals, major and minor elements and oxygen and carbon isotopes and their variation with water depth in cool, temperate carbonates, western Tasmania, Australia.Marine Geology, v. 103, p. 249–272.CrossRefGoogle Scholar
  33. RAO, C.P. and NELSON, C.S., 1992, Oxygen and carbon isotope fields for temperate shelf carbonates from Tasmania and New Zealand:Marine Geology, v. 103, p. 273–286.CrossRefGoogle Scholar
  34. RAO, C.P. and JAYAWARDANE, M.P.J., 1993 Mineralogy and geochemistry of modern temperate carbonates from King Island, Tasmania, Australia:Carbonates and Evaporites, v. 8, p. 170–180.CrossRefGoogle Scholar
  35. RAO, C.P. and JAYAWARDANE, M.P.J., 1994, Major minerals, elemental and isotopic composition in modern temperate shelf carbonates, eastern Tasmania, Australia: Implications for the occurrence of extensive ancient nontropical carbonates:Palaeogeography, Palaeoclimatology, Palaeoecology, v. 107, p. 49–63.CrossRefGoogle Scholar
  36. RAO, C.P., and HUSTON, D., 1995, Formation of temperate shelf carbonates by mixing of water masses: Seawater temperatures, salinity and oxygen and carbon isotope fractionation, eastern Tasmania, Australia:Carbonates and Evaporites, v. 10, p. 105–113.CrossRefGoogle Scholar
  37. SMITH, A.M., NELSON, C.S. and DANAHER, P.J., 1992, Dissolution behaviour of bryozoan sediments: Taphonomic implications for nontropical shelf carbonates:Palaeogeography, Palaeoclimatology, Palaeoecology, v. 93, p. 213–226.CrossRefGoogle Scholar
  38. VEIZER, J., 1983, Chemical diagenesis of carbonates: Theory and application of trace element technique,in Stable Isotopes in Sedimentary Geology, SEPM Short Course, v. 10, p. 1–100.Google Scholar
  39. WASS, R.E., CONOLLY, R.J. and MACINTYRE, R.J., 1970. Bryozoan carbonate sand continuous along southern Australia:Marine Geology, v. 9, p. 63–73.CrossRefGoogle Scholar
  40. WILSON, J.L., 1975. Carbonate facies in geologic time. Springer-Verlag, New York, 471 p.CrossRefGoogle Scholar

Copyright information

© Springer 1995

Authors and Affiliations

  • C. Prasada Rao
    • 1
  • Zahra Z. Amini
    • 1
  1. 1.Department of GeologyUniversity of TasmaniaHobartAustralia

Personalised recommendations