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Carbonates and Evaporites

, Volume 8, Issue 2, pp 135–148 | Cite as

Physical versus chemical processes of “whiting” formation in the Bahamas

  • Stephen K. Boss
  • A. Conrad Neumann
Article

Abstract

Whitings are common yet problematic occurrences of highly turbid water parcels among the relatively clear waters of shallow, tropical and subtropical carbonate platforms, banks and seas (e.g. Bahamas, Belize, Gulf of Carpentaria, Persian Gulf). In this paper, existing data on Bahamian whitings are scrutinized in an attempt to identify processes which may account for whiting phenomena worldwide.

An examination of the areal distribution of whitings on Great Bahama Bank shows that>90% are associated with either mud or pellet-mud sediment facies. In view of this non-random distribution, several prominent hypotheses of whiting origin are considered: a) resuspension of fine-grained sediment by bottom-feeding fish (fish-muds); b) largescale, instantaneous physicochemical precipitation events; c) large-scale carbonate precipitation incidental to planktonic algal blooms; d) bottom sediment resuspension as a result of turbulent tidal flow. Although none of the above hypotheses can be discounted completely, this paper proposes that the observed geographic and physical characteristics of whitings are consistent with predicted and observed characteristics of turbulent-flow systems; that whitings are the observable manifestation of the “bursting” cycle of turbulence production at flow boundaries.

The bursting process is a primary source of turbulence emanating from flow boundaries and can generate velocity excursions which deviate from mean flow velocity by a factor of 4. Published data for mean tidal current velocities on Great Bahama Bank range from 8 to 50 cm s−1. Thus, maximum predictable velocities during the bursting process will range from 32 to 200 cm s−1, quite in excess of empirically determined threshold sand-transport velocities (<25 cm s−1). Four-fold velocity excursions during turbulent flow increase shear stress up to 4-fold and generate 16-fold increases in lift force at the sediment water interface, enhancing bottom-sediment destabilization, particle entrainment and suspension. The visible, roiling nature of whiting water parcels is believed to be the expression of the above turbulent flow processes on Great Bahama Bank. Organization of turbulent boundary-layer flow into alternating low- and high-velocity “streaks” gives rise to alternating zones of active sediment-resuspension and deposition and may account for the development of subparallel digitations frequently observed within whitings.

An integrated, conceptual explanation of whiting distribution on Great Bahama Bank is proposed which considers the interaction of physical environmental energy and sediment textural characteristics across the bank-top. Despite high tidal-current, wind and wave energy flux (and sediment resuspension potential) near bank margins, whitings are rare because sediments are nearly devoid of mud-sized particles. Near Andros Island, carbonate-mud is plentiful but whitings are infrequent because deposition occurs in the tidal- and wind-energy shadow of the island. Only on the center of the bank-top is environmental energy (sediment resuspension potential) sufficiently high and carbonate-mud sufficiently abundant for whitings to originate. Evaluation of this proposed whiting generation concept requires an interdisciplinary understanding of chemical, physical, sedimentological and biological aspects of the Great Bahama Bank environment.

Keywords

Bottom Sediment Aragonite Lift Force Turbulence Production Bottom Shear Stress 
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.

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References

  1. BATHURST, R.G.C., 1967, Subtidal gelatinous mat, sand stabilizer and food, Great Bahama Bank:Jour. of Geology, v. 75, pp. 736–738.CrossRefGoogle Scholar
  2. BATHURST, R.G.C., 1971, Carbonate Sediments and Their Diagenesis. Elsevier, Amsterdam, 658 pp.Google Scholar
  3. BROECKER, W.S. & TAKAHASHI, T., 1966, Calcium carbonate precipitation on the Bahama Banks:Jour. of Geophysical Research, v. 71, pp. 1575–1602.CrossRefGoogle Scholar
  4. CLOUD, P.E., Jr., 1962a, Environment of calcium carbonate deposition west of Andros Island, Bahamas. United States Geological Survey Professional Paper 350, 138 pp.Google Scholar
  5. CLOUD, P.E., Jr., 1962b, Behaviour of calcium carbonate in sea water:Geochimica et Cosmochimica Acta, v. 26, pp. 867–884.CrossRefGoogle Scholar
  6. CRAIG, H., 1954, Carbon 13 in plants and the relationships between carbon 13 and carbon 14 variations in nature:Jour. of Geology, v. 62, pp. 115–149.CrossRefGoogle Scholar
  7. DAILY, J.W. & HARLEMAN, D.R.F., 1966, Fluid Dynamics. Addison Wesley Publishing Co., Reading, MA, 454 pp.Google Scholar
  8. DAMON, P.E., LERMAN, J.C. anld LONG, A., 1978, Temporal fluctuations of atmospheric14C: Causal factors and implications:Annual Reviews of Earth and Planetary Sciences, v. 6, pp. 457–494.CrossRefGoogle Scholar
  9. EINSTEIN, H.A. & EL-SAMNI, E-S.A., 1949, Hydrodynamic forces on a rough wall:Reviews of Modern Physics, v. 21, pp. 520–524.CrossRefGoogle Scholar
  10. FRIEDMAN, G.M., 1965, On the origin of aragonite in the Dead Sea:Israel Jour. of Earth-Sciences, v. 14, pp. 79–85.Google Scholar
  11. GINSBURG, R.N., 1956, Environmental relationships of grain size and constituent particles in some south Florida carbonate sediments:American Association of Petroleum Geologists Bulletin, v. 36, pp. 2384–2427.Google Scholar
  12. GORDON, C.M., 1975, Sediment entrainment and suspension in a turbulent tidal flow:Marine Geology, v. 18, M57-M64.CrossRefGoogle Scholar
  13. GORDON, C.M. and DOHNE, C.F., 1973, Some observations of turbulent flow in a tidal estuary:Journal of Geophysical Research, v. 78, pp. 1971–1978.CrossRefGoogle Scholar
  14. GRASS, A.J., 1971, Structural features of turbulent flow over smooth and rough boundaries:Jour. of Fluid Mechanics, v. 50, pp. 233–255.CrossRefGoogle Scholar
  15. HEATHERSAHW, A.D., 1974, “Bursting” phenomena in the sea:Nature, v. 248, pp. 394–395.CrossRefGoogle Scholar
  16. KIM, H.T., KLINE, S.J. & REYNOLDS, W.C., 1971, The production of turbulence near a smooth wall in a turbulent boundary layer:Jour. of Fluid Mechanics, v. 50, pp. 133–160.CrossRefGoogle Scholar
  17. KLINE, S.J., REYNOLDS, W.C., SCHRAUB, F.A. & RUNSTADLER, P.W., 1967, The structure of turbulent boundary layers:Jour. of Fluid Mechanics, v. 30, pp. 741–773.CrossRefGoogle Scholar
  18. LIBBY, W.F., 1955, Radiocarbon Dating. University of Chicago Press, Chicago, 175 pp.Google Scholar
  19. MIDDLETON, G.V. & SOUTHARD, J.B., 1984, Mechanics of sediment movement: Society of Economic Paleontologists and Mineralogists Short Course 3, 401 pp.Google Scholar
  20. MORSE, J.W., THURMOND, V., BROWN, E. & OSTLUND, H.G., 1984, The carbonate chemistry of Grand Bahama Bank waters: after 18 years an other look:Jour. of Geo-Physical Research, v. 89, pp. 3604–3614.CrossRefGoogle Scholar
  21. NEUMANN, A.C., GEBELEIN, C.D. & SCOFFIN, T.P., 1970, The composition, structure, and erodability of subtidal algal mats, Abaco, Bahamas:Jour. of Sedimentary Petrology, v. 40, pp. 274–297.Google Scholar
  22. NEUMANN, A.C. and LAND, L.S., 1975, Lime mud deposition and calcareous algae in the Bight of Abaco, Bahamas: a budget:Jour. of Sedimentary Petrology, v. 45, pp. 763–786.Google Scholar
  23. NEWELL, N.D., IMBRIE, J., PURDY, E.G. & THURBER, D.L., 1959, Organism communities and bottom facies, Great Bahama Bank:Bulletin of the American Museum of Natural History, v. 117, pp. 177–228.Google Scholar
  24. PURDY, E.G., 1963, Recent calcium carbonate facies of the Great Bahama Bank. 2. Sedimentary facies:Jour. of Geology, v. 71, pp. 472–497.CrossRefGoogle Scholar
  25. PUSEY, W.C., III, 1975, Holocene carbonate sedimenation on the northern Belize shelf: In Wantland, K.F. and Pusey, W.C., III (eds.), Belize Shelf — Carbonate sediments, clastic sediments, and ecology:American Association of Petroleum Geologists Studies in Geology, No.2, pp. 131–233.Google Scholar
  26. ROBBINS, L.L. & BLACKWELDER, P.L., 1990, Origin of whitings: A biologically induced nonskeletal mechanism:American Association of Petroleum Geologists Bulletin, v. 74, pp. 749.Google Scholar
  27. ROBBINS, L.L. & BLACKWELDER, P.L., 1992, Biochemical and ultrastructural evidence for the origin of whitings: A biologically induced calcium carbonate precipitation mechanism:Geology, v. 20, pp. 464–468.CrossRefGoogle Scholar
  28. SENGUPTA, A., 1979, Grain-size distribution of suspended load in relation to bed materials and flow velocity:Sedimentology, v. 26, pp. 63–82.CrossRefGoogle Scholar
  29. SHINN, E.A., STEINEN, R.P., LIDZ, B.H. & SWART, P.K., 1989, Whitings, a sedimentologic dilemma:Jour. Sedimentary Petrology, v. 59, pp. 147–161.CrossRefGoogle Scholar
  30. SMITH, C.L., 1940, The Great Bahama Bank: 1. General hydrographic and chemical factors.Journal of Marine Resources, Sears Foundation for Marine Research, III, pp. 147–170.Google Scholar
  31. TRAGANZA, E.D., 1967, Dynamics of the carbon dioxide system on the Great Bahama Bank:Bulletin of Marine Science, v. 17, pp. 348–366.Google Scholar
  32. WELLS, A.J. and ILLING, L.V., 1964, Present-day precipitation of calcium carbonate in the Persian Gulf: In Van Straaten, L.M.J.U. (ed.), Deltaic and shallow marine deposits Proceedings of the 6th International Sedimentological Congress, 1963, p. 429–435.Google Scholar

Copyright information

© Springer 1993

Authors and Affiliations

  • Stephen K. Boss
    • 1
  • A. Conrad Neumann
    • 1
  1. 1.Curriculum in Marine SciencesUniversity of North CarolinaChapel Hill

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