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Time and taphonomy: quantitative estimates of time-averaging and stratigraphic disorder in a shallow marine habitat

Published online by Cambridge University Press:  08 February 2016

Karl W. Flessa
Affiliation:
Department of Geosciences, University of Arizona, Tucson, Arizona 85721
Alan H. Cutler
Affiliation:
Department of the Geophysical Sciences, University of Chicago, 5734 South Ellis Avenue, Chicago, Illinois 60637
Keith H. Meldahl
Affiliation:
Department of Geology, Oberlin College, Oberlin, Ohio 44074

Abstract

We examined the radiocarbon age, taphonomic condition and stratigraphic position of shells of the venerid bivalve Chione spp. from the tidal flats of Bahia la Choya, Sonora, Mexico. Shells in Bahia la Choya are time-averaged. Thirty shells yielded radiocarbon dates from modern (A.D. 1950 or younger) to 3569 years before present. The median calendar age of inner flat shells is 483 years; the median age of tidal channel shells is 427 years. We interpret such long shell survival to be the result of frequent shallow burial. Such burial retards bioerosion of shells.

The taphonomic condition of shells varied with environment. Shells from the surface of the inner flats were better preserved than shells from the tidal channel. Shells are more likely to be physically worn and biologically degraded in the waters of the channel than on the quieter and more frequently exposed inner tidal flat. Taphonomic condition is an unreliable indicator of a shell's time-since-death. Poorly-preserved shells on the inner flats tended to be old, but in general shell condition was much more variable than shell age. A shell's condition is more likely the result of its total residence time on the surface than its time-since-death (surface time plus burial time).

Two composite short (44 cm and 50 cm) cores revealed varying degrees of stratigraphic disorder (the departure from perfect correlation between relative stratigraphic position and relative age). One of eight shells in the inner flats core was disordered; four of nine shells in the tidal channel were disordered. The actual age range of surface shells approximates the age range of shells in cores. Stratigraphic disorder is a consequence of both time-averaging and physical and biogenic mixing.

Time-averaging controls the degree of precision possible in paleoecological studies. Environmental changes and ecological phenomena occurring within a span of 3500 years would not be recognized in deposits like those of Bahia la Choya. Time-averaging and stratigraphic disorder also constrain the temporal resolution possible in microstratigraphic studies of evolution. The extent of time-averaging and stratigraphic disorder will dictate an appropriate sample interval. In order to prevent temporal overlap between successive samples in deposits like Bahia la Choya, sample spacing should not be less than approximately 0.5 m.

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Articles
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Copyright © The Paleontological Society 

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References

Literature Cited

Allmon, W. D. 1989. Paleontological completeness of the record of lower Tertiary mollusks, U.S. Gulf and Atlantic Coastal Plains: implications for phylogenetic studies. Historical Biology 3:141158.CrossRefGoogle Scholar
Badgley, C. 1982. How much time is represented in the present: the development of time-average modern assemblages as models for the fossil record. Third North American Paleontological Convention, Proceedings 1:2328.Google Scholar
Behrensmeyer, A. K. 1982. Time resolution in fluvial vertebrate assemblages. Paleobiology 8:211227.CrossRefGoogle Scholar
Behrensmeyer, A. K. 1991. Terrestrial vertebrate accumulations. Pp. 291335 in Allison, P. A. and Briggs, D. E. G., eds. Taphonomy. Releasing the data locked in the fossil record. Plenum, New York.CrossRefGoogle Scholar
Behrensmeyer, A. K., and Schindel, D. 1983. Resolving time in paleobiology. Paleobiology 9:18.CrossRefGoogle Scholar
Berger, R., Taylor, R. E., and Libby, W. F. 1966. Radiocarbon content of marine shells from the California and Mexican west coast. Science 153:864866.CrossRefGoogle ScholarPubMed
Bjerlykke, K., Bue, B., and Elverhoi, A. 1978. Quaternary sediments in the northwestern part of the Barents Sea and their relation to the underlying Mesozoic bedrock. Sedimentology 25:227246.CrossRefGoogle Scholar
Bowman, S. 1990. Radiocarbon dating. University of California Press, Berkeley.Google Scholar
Brandt, D. S. 1989. Taphonomic grades as a classification for fossiliferous assemblages and implications for paleoecology. Palaios 4:303309.CrossRefGoogle Scholar
Brett, C. E., and Baird, G. C. 1986. Comparative taphonomy: a key to paleoenvironmental interpretation based on fossil preservation. Palaios 1:207227.CrossRefGoogle Scholar
Brett, C. E., and Seilacher, A. 1991. Fossil Lagerstatten: a taphonomic consequence of event stratification. Pp. 283297 in Einsele, G., Ricken, W., and Seilacher, A., eds. Cycles and events in stratigraphy. Springer, Berlin.Google Scholar
Burchuladze, A. A., and Togonidze, G. I. 1987. Tbilisi radiocarbon dates IV. Radiocarbon 29:239262.CrossRefGoogle Scholar
Cadee, G. C. 1968. Molluscan bioceonoses and thanatocoenoses in the Ria de Arosa, Galacia, Spain. Rijksmuseum van Natuurlijke Histoire te Leiden, Zoologische Verhandelingen 95:1121.Google Scholar
Cadee, G. C. 1991. Feeding traces and bioturbation by birds on a tidal flat, Dutch Wadden Sea. Ichnos 1:2330.CrossRefGoogle Scholar
Cummins, H., Powell, E. N., Stanton, R. J. Jr., and Staff, G. 1986. The rate of taphonomic loss in modern benthic habitats: How much of the potentially preservable community is preserved? Palaeogeography, Palaeoclimatology, Palaeoecology 52:291320.CrossRefGoogle Scholar
Cutler, A. H. 1987. Surface textures of shells as taphonomic indicators. Paleontological Society Special Publication 2:164176.CrossRefGoogle Scholar
Cutler, A. H. 1989. Shells survive—loss, persistence and accumulation of hardparts in shallow marine sediments. Geological Society of America Abstracts with Programs 20:A71.Google Scholar
Cutler, A. H. 1991a Processes of hardpart breakdown and models of stratigraphic disorder in shallow marine environments Ph.D. dissertation. University of Arizona, Tucson, Arizona.Google Scholar
Cutler, A. H. 1991b Avoiding stratigraphic disorder: sampling strategies for shallow marine strata Geological Society of America Abstracts with Programs 22:A81.Google Scholar
Cutler, A. H., and Flessa, K. W. 1990. Fossils out of sequence: computer simulations and strategies for dealing with stratigraphic disorder. Palaios 5:227235.CrossRefGoogle Scholar
Davies, D. J., Powell, E. N., and Stanton, R. J. Jr. 1989a Taphonomic signature as a function of environmental process: shells and shell beds in a hurricane-influenced inlet on the Texas coast Palaeogeography, Palaeoclimatology, Palaeoecology 72:317356.CrossRefGoogle Scholar
Davies, D. J., Powell, E. N., and Stanton, R. J. Jr. 1989b. Relative rates of shell dissolution and net sediment accumulation—a commentary: can shell beds form by the gradual accumulation of biogenic debris on the sea floor? Lethaia 22:207212.CrossRefGoogle Scholar
Einsele, G., Elouard, P., Herm, D., Kogler, F. C., and Schwartz, H. U. 1977. Source of biofacies of Late Quarternary sediments in relation to sea level off Mauritania, West Africa. “Meteor” Forschungs-Ergebnisse, Reihe C, No. 26:143.Google Scholar
Ekdale, A. A. 1987. Late Cenozoic rocks in the Puerto Penasco area. Paleontological Society Special Publication 2:3443.CrossRefGoogle Scholar
Eldridge, K. L., Stipp, J. J., and Hattner, J. 1976. University of Miami radiocarbon dates V. Radiocarbon 18:116124.CrossRefGoogle Scholar
Feige, A., and Fursich, F. T. 1991. Taphonomy of the Recent molluscs of Bahia la Choya (Gulf of California, Sonora, Mexico). Zitteliana 18:89133.Google Scholar
Flessa, K. W., ed. 1987. Paleoecology and taphonomy of Recent to Pleistocene intertidal deposits. Gulf of California. Paleontological Society Special Publication 2.CrossRefGoogle Scholar
Flessa, K. W., and Brown, T. J. 1983. Selective solution of macroinvertebrate calcareous hard parts. Lethaia 16:193205.CrossRefGoogle Scholar
Flessa, K. W., and Fursich, F. T. 1991. Quantitative analyses of molluscan communities and taphocoenoses of Bahia la Choya (Gulf of California, Sonora, Mexico). Zitteliana 18:7988.Google Scholar
Flessa, K. W., Cutler, A. H., Meldahl, K. H., and Fursich, F. T. 1989. Taphonomic processes and stratigraphic disorder. Abstract, 28th International Geological Congress, Washington, D.C., p. 1493-1–494.Google Scholar
Frey, R. W., and Howard, J. D. 1986. Taphonomic characteristics of offshore mollusk shells, Sapelo Island, Georgia. Tulane Studies in Geology and Paleontology 19:5161.Google Scholar
Fursich, F. T. 1978. The influence of faunal condensation and mixing on the preservation of fossil benthic communities. Lethaia 11:243250.CrossRefGoogle Scholar
Fursich, F. T., and Aberhan, M. 1990. Significance of timeaveraging for paleocommunity analysis. Lethaia 23:143152.CrossRefGoogle Scholar
Fursich, F. T., and Flessa, K. W. 1987. Taphonomy of tidal flat molluscs in the northern Gulf of California: paleoenvironmental analysis despite the perils of preservation. Palaios 2:543559.CrossRefGoogle Scholar
Fursich, F. T., and Flessa, K. W., eds. 1991. Ecology, taphonomy, and paleoecology of Recent and Pleistocene molluscan faunas of Bahia la Choya, northern Gulf of California. Zitteliana 18:1180.Google Scholar
Fursich, F. T., Flessa, K. W., Aberhan, M., Feige, A., and Schodelbauer, S. 1991. Sedimentary habitats and molluscan faunas of Bahia la Choya (Gulf of California, Sonora, Mexico). Zitteliana 18:551.Google Scholar
Glover, C. P., and Kidwell, S. M. 1993. The role of intraskeletal organics in the early post-mortem reactivity of molluscan aragonite. Journal of Geology 103 (in press).Google Scholar
Grant, J. 1983. The relative magnitude of biological and physical sediment reworking in an intertidal community. Journal of Marine Research 41:673689.CrossRefGoogle Scholar
Haynes, G. 1980. Evidence of carnivore gnawing on Pleistocene and Recent mammalian bones. Paleobiology 6:341351.CrossRefGoogle Scholar
Henderson, S. W., and Frey, R. W. 1986. Taphonomic redistribution of mollusk shells in a tidal inlet channel, Sapelo Island, Georgia. Palaios 1:316.CrossRefGoogle Scholar
Howard, J. D., Mayou, T. V., and Heard, R. W. 1977. Biogenic sedimentary structures formed by rays. Journal of Sedimentary Petrology 47:339346.Google Scholar
Hubbs, C. L., Bien, G. S., and Suess, H. E. 1965. La Jolla natural radiocarbon measurements IV. Radiocarbon 7:66117.CrossRefGoogle Scholar
Kershaw, P. J., Swift, D. J., and Denoon, D. C. 1988. Evidence of Recent sedimentation in the eastern Irish Sea. Marine Geology 85:114.CrossRefGoogle Scholar
Kidwell, S. M. 1982. Time scales of fossil accumulations: patterns from Miocene benthic assemblages. Third North American Paleontological Convention, Proceedings 1:295300.Google Scholar
Kidwell, S. M. 1986. Models for fossil concentrations: paleobiology implications. Paleobiology 12:624.CrossRefGoogle Scholar
Kidwell, S. M. 1991. The stratigraphy of shell concentrations. Pp. 211290 in Allison, P. A. and Briggs, D. E. G., eds. Taphonomy. Releasing the data locked in the fossil record. Plenum, New York.CrossRefGoogle Scholar
Kidwell, S. K., and Bosence, D. J. 1991. Taphonomy and timeaveraging of marine shelly faunas. Pp. 115209 in Allison, P. A. and Briggs, D. E. G., eds. Taphonomy. Releasing the data locked in the fossil record. Plenum, New York.CrossRefGoogle Scholar
Maclntyre, I. G., Pilkey, O. H., and Stuckenrath, R. 1978. Relict oysters on the United States Atlantic continental shelf: a consideration of their usefulness in understanding late Quaternary sea-level history. Geological Society of America Bulletin 89:277282.2.0.CO;2>CrossRefGoogle Scholar
Meldahl, K. H. 1987a Sedimentologic and taphonomic implications of biogenic stratification Palaios 2:350358.CrossRefGoogle Scholar
Meldahl, K. H. 1987b Origin of shell beds and evolution of a shelly sand spit, Bahia la Choya, northern Gulf of California Paleontological Society Special Publication 2:189199.CrossRefGoogle Scholar
Meldahl, K. H. 1990. Paleoenvironmental and stratigraphic implications of taphonomic processes: case studies from Recent and Pleistocene shallow marine environments. Ph.D. dissertation. University of Arizona, Tucson, Arizona.Google Scholar
Meldahl, K. H., and Flessa, K. W. 1990. Taphonomic pathways and comparative biofacies and taphofacies in a Recent intertidal/shallow shelf environment. Lethaia 23:4360.CrossRefGoogle Scholar
Nelson, C. S., and Bornhold, B. D. 1983. Temperate skeletal carbonate sediments on Scott Shelf, northeastern Vancouver Island, Canada. Marine Geology 52:241246.CrossRefGoogle Scholar
Neumann, A. C. 1966. Observations of coastal erosion in Bermuda and measurements of the boring rates of the sponge Cliona lampa. Limnology and Oceanography 11:92108.CrossRefGoogle Scholar
Norris, R. D. 1986. Taphonomic gradients in shelf fossil assemblages: Pliocene Purisma Formation, California. Palaios 1:256270.CrossRefGoogle Scholar
Ortlieb, L. 1991. Quaternary shorelines along the northeastern Gulf of California: geochronological data and neotectonic implications. Geological Society of America Special Paper 254:95120.CrossRefGoogle Scholar
Panin, N., Panin, S., Herz, N., and Noakes, J. E. 1983. Radiocarbon dating of Danube Delta deposits. Quaternary Research 19:249255.CrossRefGoogle Scholar
Parsons, K. M., and Brett, C. E. 1991. Taphonomic processes and biases in modern marine environments: an actualistic perspective on fossil assemblage preservation. Pp. 2265 in Donovan, S. K., ed. The processes of fossilization. Columbia University Press, New York.Google Scholar
Pearson, F. J., Davis, E. M., and Tamers, H. A. 1966. University of Texas radiocarbon dates IV. Radiocarbon 8:453466.CrossRefGoogle Scholar
Perkins, R. D., and Tsentas, C. J. 1976. Microbial infestations of carbonate substrates planted on the St. Croix shelf, West Indies. Geological Society of American Bulletin 87:16151628.2.0.CO;2>CrossRefGoogle Scholar
Peterson, C. H. 1976. Relative abundance of living and dead molluscs in two California lagoons. Lethaia 9:137148.CrossRefGoogle Scholar
Peterson, C. H. 1991. Intertidal zonation of marine invertebrates in sand and mud. American Scientist 79:236249.Google Scholar
Powell, E. N., and Davies, D. J. 1990. When is an “old” shell really old? Journal of Geology 98:823844.CrossRefGoogle Scholar
Powell, E. N., Logan, A., Stanton, R. J. Jr., Davies, D. J., and Hare, P. E. 1989. Estimating time-since-death from the free-amino acid content of the mollusc shell: a measure of time-averaging in modern death assemblages? Description of the technique. Palaios 4:1631.CrossRefGoogle Scholar
Powell, E. N., Staff, G., Davies, D. J., and Callendar, W. R. 1989. Macrobenthic death assemblages in modern marine environments: formation, interpretation and application. CRC Critical Reviews in Aquatic Science 1:555589.Google Scholar
Powell, E. N., King, J. A., and Boyles, S. 1991. Dating time-sincedeath of oyster shells by the rate of decomposition of the organic matrix. Archaeometry 33:5168.CrossRefGoogle Scholar
Rhoads, D. C., and Stanley, D. J. 1965. Biogenic graded bedding. Journal of Sedimentary Petrology 35:956963.Google Scholar
Sadler, P. M. 1981. Sediment accumulation rates and the completeness of stratigraphic sections. Journal of Geology 89:569584.CrossRefGoogle Scholar
Schindel, D. E. 1980. Microstratigraphic sampling and the limits of paleontologic resolution. Paleobiology 6:408426.CrossRefGoogle Scholar
Schindel, D. E. 1982. Time resoulution in cyclic Pennsylvanian strata: implications for evolutionary patterns in Glabrocingulum (Mollusca: Archaeogastropoda). Third North American Paleontological Convention, Proceedings 2:482a482e.Google Scholar
Speyer, S. E., and Brett, C. E. 1986. Trilobite taphonomy and Middle Devonian taphofacies. Palaios 1:312327.CrossRefGoogle Scholar
Speyer, S. E., and Brett, C. E. 1988. Taphofacies models for epeiric sea environments: Middle Paleozoic examples. Palaeogeography, Palaeoclimatology, Palaeoecology 63:225262.CrossRefGoogle Scholar
Staff, G. M., Stanton, R. J. Jr., Powell, E. N., and Cummins, H. 1986. Time averaging, taphonomy and their impact on paleocommunity reconstruction: death assemblages in Texas bays. Geological Society of America Bulletin 97:428443.2.0.CO;2>CrossRefGoogle Scholar
Stuiver, M., and Kra, R., eds. 1986. Calibration issue. 12th International Radiocarbon Conference. Radiocarbon 28:8051030.CrossRefGoogle Scholar
Stuiver, M., and Polach, H. A. 1977. Discussion: reporting of M C data. Radiocarbon 19:355363.CrossRefGoogle Scholar
Stuiver, M., and Reimer, P. J. 1986. A computer program for radiocarbon age calibration. Radiocarbon 28:10221030.CrossRefGoogle Scholar
Stuiver, M., Pearson, G. W., and Braziunas, T. 1986. Radiocarbon age calibration of marine samples back to 9000 cal yr BP. Radiocarbon 28:9801021.CrossRefGoogle Scholar
Sumpter, L. T. 1987. Grain size and provenance of Bahia la Choya sediments. Paleontological Society Special Publication 2:4451.CrossRefGoogle Scholar
Thomson, D. A., Mead, A. R., and Schreiber, J. F. Jr. 1969. Environmental impact of brine effluents on Gulf of California. U.S. Department of Interior, Research and Development Progress Report No. 387.Google Scholar
Tudhope, A. W., and Risk, M. J. 1985. Rate of dissolution of carbonate sediments by microboring organisms, Davies Reef, Australia. Journal of Sedimentary Petrology 55:440447.Google Scholar
van Straaten, L. M. J. U. 1952. Biogenic textures and the formation of shell beds in the Dutch Wadden Sea. Proceedings, Koninklijke Nederlandse Akademie van Wetenschappen. Series B, Physical Sciences 55:500516.Google Scholar
Walbran, P. D., Henderson, R. A., Jull, A. J. T., and Head, M. J. 1989a Evidence from sediment of long-term Acanthaster planci predation on corals of the Great Barrier Reef Science 245:847850.CrossRefGoogle ScholarPubMed
Walbran, P. D., Henderson, R. A., Faithful, J. W., Polach, H. A., Sparks, R. J., Wallace, G., and Lowe, D.C. 1989b Crown-of-thorns starfish outbreaks on the Great Barrier Reef: a geological perspective based upon the sediment record Coral Reefs 8:6778.CrossRefGoogle Scholar
Walker, K. R., and Bambach, R. K. 1971. The significance of fossil assemblages from fine-grained sediments: time-averaged communities. Geological Society of American Abstracts with Programs 3:783784.Google Scholar
Wilson, J. B. 1979. Biogenic carbonate sediments on the Scottish continental shelf and on Rockall Bank. Marine Geology 33:8593.CrossRefGoogle Scholar