Abstract
Sediments of Lake Fidler, a meromictic lake in south-west Tasmania, contain distinctive laminae. In order to determine their composition and formation, these laminae were studied using a combination of X- ray analysis, scanning electron microscopy, X-ray diffraction and vibrational spectrometry. Results indicated that the laminae were composed of clay originating from the adjacent Gordon River estuary. The clay was also found as part of the general sediment matrix of the core. The evidence indicates that the laminae are formed during incursions of brackish water from the adjacent Gordon River estuary into Lake Fidler which cause the flocculation of clay minerals in the water column. These clay minerals then sink rapidly to the sediments to form laminae. Although the formation of these laminae pre-dates meromixis, their mode of formation corroborates the theory that meromixis is maintained ectogenically by periodic inflows of brackish water replenishing monimolimnetic salts.
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References
Anderson, R. Y., W. E. Dean, J. Platt Bradbury & D. Love, 1985. Meromictic lakes and varved sediments in North America. US Geol. Surv. Bull. 1607: 1–19.
Axelsson, V., 1983. The use of X-ray radiographic methods in studying sedimentary properties and rates of sediment accumulation. Hydrobiologia 103: 65–69.
Bowling, L. C. & P. A. Tyler, 1984. Endangered lakes of scientific and cultural value in the World Heritage Area of South-West Tasmania. Biol. Cons. 30: 201–209.
Charles, D. F., J. P. Smol & D. R. Engstrom, 1994. Palaeolimnological approaches to biological monitoring. In: Loeb, S. L. & A. Spacie (eds) Biological Monitoring of Aquatic Ecosystems. Lewis Publishers, Boca Raton. 233–293.
Dickman, M., 1979. A possible varving mechanism for meromictic lakes. Quaternary Res. 11: 113–124.
Edzwald, J. K. & C. R. O'Melia, 1975. Clay distributions in recent estuarine sediments. Clay Miner. 23: 39–44.
Gadsden, J. A., 1975. Infrared Spectra of Minerals and Related Inorganic Compounds. Butterworths, London, 277 pp.
Goehle, K. H. & J. F. Storr, 1978. Biological layering resulting from extreme meromictic stability, Devil's Hole, Abaco Island, Bahamas. Verh. Int. Verein. Limnol. 20: 550–555.
Hamblin, W., 1962. X-ray radiography in the study of structures in homogeneous sediments. J. Sed. Petrol. 32: 201–210.
Harle, K. J., D. A. Hodgson & P. A. Tyler, Palynological evidence for Holocene palaeoenvironments from the lower Gordon River valley, in the World Heritage Area of southwest Tasmania. The Holocene (Subm.)
Hodgson, D. A. & P. A. Tyler, 1996. The impact of a hydro-electric dam on the stability of meromictic lakes in south west Tasmania, Australia. Arch. Hydrobiol. 137(3): 301–323.
Hodgson, D. A., P. A. Tyler & W. Vyverman, 1997. The palaeolimnology of Lake Fidler, a meromictic lake in south west Tasmania and the significance of recent human impact. J. Paleolimnol. 18: 313–333.
Hodgson, D. A., S. W. Wright, P. A. Tyler & N. Davies, 1998. Analysis of fossil pigments from algae and bacteria in meromictic Lake Fidler, Tasmania, and its application to lake management. J. Paleolimnol. 19: 1–22.
Hyne, N. J., L. W. Laidig & W. A. Cooper, 1979. Prodelta sedimentation on a lacustrine delta by clay mineral flocculation. J. Sed. Petrol. 49(4): 1209–1216.
King, R. D. & P. A. Tyler, 1981. Meromictic lakes of south-west Tasmania. Aust. J. Mar. Freshwat. Res. 32: 741–756.
King, R. D. & P. A. Tyler, 1982. Lake Fidler, a meromictic lake in Tasmania. Arch. Hydrobiol. 96: 393–422.
Mattiat, B., 1970. A method for electron microscopic study of the microstructure of agrilaceous sediments. Geol. Jb. 88: 87–111.
Meade, R. H., 1972. Transport and deposition of sediments in estuaries. In: Nelson, V.W. (ed) Environmental framework of coastal plain estuaries. Geol. Soc. America Mem. 133: 91–120.
O'sullivan, P., 1983. Annually laminated lake sediments and the study of Quaternary environmental changes-a review. Quat. Sci. Rev. 1: 245–313.
Plint, A. G., 1983. Facies, environments and sedimentary cycles in the Middle Eocene, Bracklesham Formation of the Hampshire Basin: evidence for global sea level changes. Sedimentology 30: 625–653.
Tracey, B., N. Lee & V. Card, 1996. Sediment indicators of meromixis: comparison of laminations, diatoms and sediment chemistry in Brownie Lake, Minneapolis, USA. J. Paleolimnol. 15: 129–132.
Tyler, P. A., 1986. Anthropological limnology in the Land of Moinee. In: De Deckker, P. & W. D. Williams (eds) Limnology in Australia. C.S.I.R.O., Melbourne & W. Junk, Dordrecht, 523–537.
Walker, K. F. & G. E. Likens, 1975. The stability of meromictic lakes in Central Washington. Limnol. Oceanogr. 30: 1–21.
Whitehouse, V. C., L. M. Jeffrey & J. D. Debrecht, 1960. Differing settling tendencies of clay minerals in saline waters. Proc. 7th Nat. Conf. Clay and Clay Minerals 1–79.
Wright, L. D. & J. M. Colemans, 1974. Mississippi River mouth processes: effluent dynamics and morphologic development. J. Geol. 82: 751–788.
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Hodgson, D.A. The formation of flocculated clay laminae in the sediments of a meromictic lake. Journal of Paleolimnology 21, 263–269 (1999). https://doi.org/10.1023/A:1008064029510
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DOI: https://doi.org/10.1023/A:1008064029510