Arquitetura sedimentar e evolução de um sistema de cordões litorâneos bioclásticos em Hamelin Pool, Shark Bay
DOI:
https://doi.org/10.70369/b9r4k378Palavras-chave:
coquina, cordões litorâneos, Shark Bay, GPR, depósitos bioclásticosResumo
Em Shark Bay, nas bacias hipersalinas de Hamelin Pool e L’Haridon Bight, ocorre um singular sistema holocênico de cordões litorâneos bioclásticos. Objetivando delinear um modelo deposicional e evolutivo para os cordões litorâneos nas margens leste e oeste de Hamelin Pool, foram utilizados perfis de GPR, imagens aéreas, cronologia de radiocarbono e dados sedimentológicos. O início do sistema ocorreu há cerca de 5000 anos 14C, facilitado pela abundância de conchas e condições de rebaixamento do nível do mar, com episódios de aumento do nível de água induzidos por tempestades. Os principais elementos arquiteturais observados nas seções de GPR são refletores inclinados progradantes em direção ao mar, que resultam de processos de swash-backwash na face da praia durante episódios de elevação do nível da água. Outra característica importante são depósitos diacrônicos gerados por eventos de tempestades e processos eólicos. No final do Holoceno, mudanças ambientais marcantes em Hamelin Pool são sugeridas por uma série de indicadores, como a alteração no estilo deposicional dos cordões, em geral mais baixos, e a ocorrência de um importante período erosivo após 1450 anos 14C na margem oeste. Embora as idades obtidas para os conjuntos de cordões mapeados nas margens leste e oeste de Hamelin Pool sejam semelhantes, elas exibem diferenças na arquitetura sedimentar e na morfologia costeira como resultado de diferentes graus de vulnerabilidade a tempestades e, secundariamente, a diferentes processos de ressedimentação relacionados à ação de correntes de maré, de ondas e de correntes paralelas à costa, que podem ter energia suficiente para o transporte de sedimentos no ambiente costeiro em condições de tempo bom. Propõe-se um modelo deposicional onde washovers e storm-surge ridges são depositados por episódios de overwash no pico de grandes tempestades, enquanto a construção de bermas ocorre durante a fase de waning por meio de processos de swash, backwash, transbordamento e pequenas ocorrências de overwashing.
Referências
Aigner, T., 1985, Storm depositional systems: dynamic stratigraphy in modern and ancient shallow-marine sequences: Berlin, Heidelberg, Springer-Verlag, 182 p.
Bascom, W.N., 1953, Characteristics of natural beaches: Coastal Engineering Proceedings, v. 1, n. 4, chapter 10, p. 163-180, doi: https://doi.org/10.9753/icce.v4.10.
Bendixen, M., Clemmensen, L.B., and Kroon, A., 2013, Sandy berm and beach-ridge formation in relation to extreme sea-levels: A Danish example in a micro-tidal environment: Marine Geology, v. 344, p. 53-64, doi: https://doi.org/10.1016/j.margeo.2013.07.006.
Berry, P.F., and Playford, P.E., 1997, Biology of modern Fragum erugatum (Mollusca Bivalvia, Cardiidae) in relation to deposition of the Hamelin Coquina, Shark Bay, Western Australia: Marine and Freshwater Research, v. 8, n. 5, p. 415-420.
Boyajian, G.E., and Thayer, C.W., 1995, Clam calamity; a recent supratidal storm-deposit as an analog for fossil shell beds: Palaios, v. 10, n. 5, p. 484-489, doi: https://doi.org/10.2307/3515050.
Bureau of Meteorology, n.d.a, Average annual, monthly and seasonal evaporation: http://www.bom.gov.au/jsp/ncc/climate_averages/evaporation/index.jsp (accessed July 2012).
Bureau of Meteorology, n.d.b, Tropical Cyclones Affecting Carnarvon: from http://www.bom.gov.au/cyclone/history/wa/carnarvon.shtml (accessed July 2012).
Bureau of Meteorology, n.d.c, Wind Roses for Selected Locations in Australia: http://www.bom.gov.au/climate/averages/wind/selection_map.shtml (accessed July 2012).
Butcher, B.P., Van de Graaff, W.J.E., Hocking, R.M., and Geological Survey of Western Australia, 1984, Shark Bay - Edel, Western Australia: sheets SG/49-8 and SG/49-12 international index, Perth, W.A.: Geological Survey of Western Australia.
Carvalho, M.D., Praça, U.M., Silva-Telles, A.C., Jahnert, R.J., and Dias, J.L., 2000, Bioclastic carbonate lacustrine facies models in the Campos Basin (Lower Cretaceous), Brazil, in E.H. Gierlowski-Kordesch and K.R. Kelts., eds., Lake basins through space and time: AAPG, v. 46, doi: https://doi.org/10.1306/St46706C19.
Collins, L.B., Zhao, J.X., and Freeman, H., 2006, A highprecision record of mid-late Holocene sea-level events from emergent coral pavements in the Houtman Abrolhos Islands, southwest Australia: Quaternary International, v. 145-146, p. 78-85, doi: http://doi.org/10.1016/j.quaint.2005.07.006.
Donnelly, C., Kraus, N., and Larson, M., 2006, State of knowledge on measurement and modeling of coastal overwash: Journal of Coastal Research, v. 2006, n. 224, p. 965-991, doi: https://doi.org/10.2112/04-0431.1.
Hagan, G.M., and Logan, B.W., 1974, Development of carbonate banks and hypersaline basins, Shark Bay, Western Australia, in B.W., Logan, J.F., Read, G., M. Hagan,, P. Hoffman, R.G., Brown, P.J., Woods and C.D., Gebelein., eds., Evolution and diagenesis of Quaternary carbonate sequences, Shark Bay, Western Australia, v.22: Tulsa, Oklahoma: American Association of Petroleum Geologists, p. 61-88.
Hine, A.C., 1979, Mechanisms of berm development and resulting beach growth along a barrier spit complex: Sedimentology, v. 26, n. 3, p. 333-351, doi: https://doi.org/10.1111/j.1365-3091.1979.tb00913.x.
Houser, C., and Greenwood, B., 2007, Onshore migration of a swash bar during a storm: Journal of Coastal Research, v. 2007, n. 231, p. 1-14, doi: https://doi.org/10.2112/03-0135.1.
Houser, C., Greenwood, B., and Aagaard, T., 2006, Divergent response of an intertidal swash bar: Earth Surface Processes and Landforms, v. 31, n. 14, p. 1775-1791, doi: https://doi.org/10.1002/esp.1365.
Jahnert, R.J., and Collins, L.B., 2011, Significance of subtidal microbial deposits in Shark Bay, Australia: Marine Geology, v. 286, n. 1-4, p. 106-111, doi: https://doi.org/10.1016/j.margeo.2011.05.006.
Jahnert, R.J., and Collins, L.B., 2012, Characteristics, distribution and morphogenesis of subtidal microbial systems in Shark Bay, Australia: Marine Geology, v. 303-306, p. 115-136, https://doi.org/10.1016/j.margeo.2012.02.009
Jahnert, R.J., and Collins, L.B., 2013, Controls on microbial activity and tidal flat evolution in Shark Bay, Western Australia: Sedimentology, v. 60, n. 4, p. 1071-1099, doi: https://doi.org/10.1111/sed.12023.
Jahnert, R.J., Paula, O., Collins, L., Strobach, E., and Pevzner, R., 2012, Evolution of a coquina barrier in Shark Bay, Australia by GPR imaging: Architecture of a Holocene reservoir analog: Sedimentary Geology, v. 281, p. 59-74, doi: https://doi.org/10.1016/j.sedgeo.2012.08.009.
Keen, T.R., and Stone, G.W., 2000, Anomalous response of beaches to hurricane waves in a low-energy environment, northeast Gulf of Mexico, USA: Journal of Coastal Research, v. 16, n. 4, p. 1100-1110.
Kelletat, D., 2006, Beachrock as sea-level indicator? Remarks from a geomorphological point of view: Journal of Coastal Research, v. 2006, n. 226, p. 1558-1564, doi: https://doi.org/10.2112/04-0328.1.
Kench, P.S., and McLean, R.F., 1997, A comparison of settling and sieve techniques for the analysis of bioclastic sediments: Sedimentary Geology, v. 109, n. 1-2, p. 111-119, doi: https://doi.org/10.1016/S0037-0738(96)00040-1.
Komar, P.D., 1998, Beach Processes and Sedimentation: Prentice Hall PTR.
Lindhorst, S., Betzler, C., and Hass, H.C., 2008, The sedimentary architecture of a Holocene barrier spit (Sylt, German Bight): Swash-bar accretion and storm erosion: Sedimentary Geology, v. 206, n. 1-4, p. 1-16, doi: https://doi.org/10.1016/j.sedgeo.2008.02.008.
Logan, B.W., and Cebulski, D.E., 1970, Sedimentary environments of Shark Bay, Western Australia, in B.W., Logan, G.R., Davies, J.F., Read and D.E., Cebulski, eds., Carbonate sedimentation and environments, Shark Bay, Western Australia: Tulsa, Oklahoma: American Association of Petroleum Geologists, v. 13, pp. 1-37.
Logan, B.W., Davies, G.R., Read, J.F., and Cebulski, D.E., 1970, Carbonate sedimentation and environments, Shark Bay, Western Australia: Tulsa, Oklahoma: American Association of Petroleum Geologists, v. 13.
Logan, B.W., Read, J.F., and Davies, G.R., 1970, History of carbonate sedimentation, Quaternary Epoch, Shark Bay, Western Australia, in B.W. Logan, G.R. Davies, J.F. Read and D.E. Cebulski, eds., Carbonate sedimentation and environments, Shark Bay, Western Australia: Tulsa, Oklahoma: American Association of Petroleum Geologists, v. 13.
Logan, B.W., Read, J.F., Hagan, G.M., Hoffman, P., Brown, R.G., Woods, P.J., and Gebelein, C.D., 1974, Evolution and diagenesis of Quaternary carbonate sequences, Shark Bay, Western Australia: Tulsa, Oklahoma: American Association of Petroleum Geologists, v. 22.
Massari, F., D'Alessandro, A., and Davaud, E., 2009, A coquinoid tsunamite from the Pliocene of Salento (SE Italy): Sedimentary Geology, v. 221, n. 1-4, p. 7-18, doi: https://doi.org/10.1016/j.sedgeo.2009.07.007.
McKee, E.D., 1959, Storm sediments on a Pacific atoll: Journal of Sedimentary Research, v. 29, n. 3, p. 354-364, doi: https://doi.org/10.1306/74d7092a-2b21-11d7-8648000102c1865d.
Morales, J.A., Borrego, J., Miguel, E.G.S., Lopez-Gonzalez, N., and Carro, B., 2008, Sedimentary record of recent tsunamis in the Huelva Estuary (southwestern Spain): Quaternary Science Reviews, v. 27, n. 7-8, p. 734-746, doi: https://doi.org/10.1016/j.quascirev.2007.12.002.
Neal, A., 2004, Ground-penetrating radar and its use in sedimentology: principles, problems and progress: Earth-Science Reviews, v. 66, n. 3-4, p. 261-330, doi: https://doi.org/10.1016/j.earscirev.2004.01.004.
Neal, A., Pontee, N.I., Pye, K., and Richards, J., 2002, Internal structure of mixed-sand-and-gravel beach deposits revealed using ground-penetrating radar: Sedimentology, v. 49, n. 4, p. 789-804, doi: https://doi.org/10.1046/j.1365-3091.2002.00468.x.
Nott, J., 2006, Tropical cyclones and the evolution of the sedimentary coast of northern Australia: Journal of Coastal Research, v. 2006, n. 221, p. 49-62, doi: https://doi.org/10.2112/05A-0005.1.
Nott, J., 2011, A 6000 year tropical cyclone record from Western Australia: Quaternary Science Reviews, v. 30, n. 5-6, p. 713-722, doi: https://doi.org/10.1016/j.quascirev.2010.12.004.
Orford, J.D., Carter, R.W., and Jennings, S.C., 1991, Coarse clastic barrier environments: evolution and implications for Quaternary sea level interpretation: Quaternary International, v. 9, p. 87-104, doi: https://doi.org/10.1016/1040-6182(91)90068-Y.
Reimer, P.J., et., 2009, IntCal09 and Marine09 radiocarbon age calibration curves, 0-50,000 years cal BP: Radiocarbon, v. 51, n. 4, p. 1111-1150, doi: https://doi.org/10.1017/S0033822200034202.
Scheffers, S.R., Scheffers, A., Kelletat, D., and Bryant, E.A., 2008, The Holocene paleo-tsunami history of West Australia: Earth and Planetary Science Letters, v. 270, n. 1-2, p. 137-146, doi: https://doi.org/10.1016/j.epsl.2008.03.027.
Tanner, W.F., 1995, Origin of beach ridges and swales: Marine Geology, v. 129, n. 1-2, p. 149-161, doi: https://doi.org/10.1016/0025-3227(95)00109-3.
Varela, A.N., Richiano, S., and Poiré, D.G., 2011, Tsunami vs storm origin for shell bed deposits in a lagoon environment: an example from the Upper Cretaceous of Southern Patagonia, Argentina: Latin American Journal of Sedimentology and Basin Analysis, v. 18, n. 1, p. 63-85.
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