Hostname: page-component-cd9895bd7-dk4vv Total loading time: 0 Render date: 2024-12-23T12:00:38.884Z Has data issue: false hasContentIssue false

Recent Sediment Flux and Erosional Processes in a Welsh Upland Lake-Catchment Based on Magnetic Susceptibility Measurements

Published online by Cambridge University Press:  20 January 2017

John A. Dearing
Affiliation:
Department of Geography, Coventry (Lanchester) Polytechnic, Coventry, England
Janet K. Elner
Affiliation:
School of Plant Biology, University College of North Wales, Bangor, Gwynedd, United Kingdom
Christine M. Happey-Wood
Affiliation:
School of Plant Biology, University College of North Wales, Bangor, Gwynedd, United Kingdom

Abstract

Single sample magnetic susceptibility measurements are used to correlate synchronous levels in 16 cores of dated (210Pb, 137Cs) recent sediment taken from the deep and oligotrophic Llyn Peris, N. Wales, in order to provide a basis for calculating total sediment and chemical influx through time. Results show that sediment influx has steadily increased since c. 1750 A.D. to reach peak levels in the period 1966–1976 A.D., equivalent to a rise in erosion in the catchment from c. 5 t km−2 yr−1 to c. 42 t km−2 yr−1. Comparison of down-core susceptibility fluctuations with sediment pollen and organic pigment data indicates that maximum susceptibility values relate to periods of channel erosion and minimum susceptibility values relate to periods of slate debris inwash from spoil tips in the catchment. A study of historical records reveals that pre-twentieth-century peak levels of erosion were due to the effects of extractive industries, while twentieth-century erosion has been caused by overgrazing, increased trampling pressure, and heavy construction works in the catchment.

Type
Original Articles
Copyright
University of Washington

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Appleby, P.G., Oldfield, F. 1978. The calculation of lead-210 dates assuming a constant rate of supply of unsupported 210Pb in the sediment. Catena 5. 18.Google Scholar
Björck, S, Dearing, J. A and Jonsson, A. (in prep.). Lithostratigraphic studies of glacial and late-glacial deposits in SE Sweden using magnetic susceptibility measurements. Boreas, in press.Google Scholar
Bloemendal, J., Oldfield, F., Thompson, R. 1979. Magnetic measurements used to assess sediment influx at Llyn Goddionduon. Nature (London) 200. 5053.CrossRefGoogle Scholar
Cathrall, W. 1928 The History of North Wales Vol. 1 J. Gleave Manchester.Google Scholar
Dearing, J.A. 1979. The application of magnetic measurements to studies of particulate flux in lake-watershed ecosystems. Unpublished Ph.D. Thesis University of Liverpool Google Scholar
Davis, M.B. 1973. Redeposition of pollen grains in lake sediments. Limnology and Oceanography 18. 4452.CrossRefGoogle Scholar
Davis, M.B. 1976. Erosion rates and land-use history in Southern Michigan. Environmental Conservation 3. 139148.CrossRefGoogle Scholar
Dodd, A.M. 1971 The Industrial Revolution in North Wales University of Wales Press Cardiff.Google Scholar
Elner, J.K., Happey-Wood, C.M. 1978. Diatom and chrysophycean cyst profiles in sediment cores from two linked but contrasting Welsh lakes. British phycological Journal 13. 341360.CrossRefGoogle Scholar
Elner, J.K., Happey-Wood, C.M. 1980. The history of two linked but contrasting lakes in North Wales from a study of pollen, diatoms and chemistry in sediment cores. Journal of Ecology 68. 95121.CrossRefGoogle Scholar
Ferrar, A.M. 1961. The depth of some lakes in Snowdonia. Geographical Journal 127. 205208.CrossRefGoogle Scholar
Gorham, E. 1960. Chlorophyll derivatives in surface muds from the English Lakes. Limnology and Oceanography 5. 2933.CrossRefGoogle Scholar
Gorham, E., Lund, J.W.G., Sanger, J.E., Dean, W.E. Jr. 1974. Some relationships between algal standing crop, water chemistry and sediment chemistry in the English Lakes. Limnology and Oceanography 19. 601617.Google Scholar
Gorham, E., Sanger, J.E. 1975. Fossil pigments in Minnesota lake sediments and their bearing upon the balance between terrestrial and aquatic inputs to sedimentary organic matter. Verhandlungen der internationale Vereinigung für theoretische und angewandte Limnologie 19. 22672273.Google Scholar
Guppy, S.F. 1974. Chemical and Primary production studies in two lakes in Snowdonia. Unpublished Ph.D. Thesis University of Wales Google Scholar
Guppy, S.F., Happey-Wood, C.M. 1978. Chemistry of sediments from two linked lakes in North Wales. Freshwater Biology 8. 401413.CrossRefGoogle Scholar
Hallberg, R.O. 1973. Palaeoredox conditions in the E. Gotland Basin during the last 400 years. Contributions from the Askö laboratory 2:1 University of Stockholm Sweden.Google Scholar
Holmes, P.W. 1968. Sedimentary studies of late-Quarternary material in Lake Windermere (Great Britain). Sedimentary Geology 2. 201224.Google Scholar
Le Borgne, E. 1955. Susceptibilité Magnétique anormale du sol superficiel. Annales de Geophysique 11. 399419.Google Scholar
Lehman, J.T. 1975. Reconstructing the rate of accumulation of lake sediment: The effect of sediment focussing. Quarternary Research 5. 541550.CrossRefGoogle Scholar
Lindsay, J. 1974 A History of the North Wales Slate Industry David and Charles Newton Abbot.Google Scholar
Mackereth, F.J.H. 1958. A portable sampler for lake deposits. Limnology and Oceanography 3. 181191.Google Scholar
Mackereth, F.J.H. 1966. Some chemical observations on post-glacial lake sediments. Philosophical Transactions of the Royal Society B 250. 165213.Google Scholar
Mackereth, F.J.H. 1969. A short core sampler for subaqueous deposits. Limnology and Oceanography 14. 154 Google Scholar
Molyneux, L., Thompson, R. 1973. Rapid measurement of the magnetic susceptibility of long cores of sediment. Geophysical Journal of the Royal Astronomical Society 32. 479481.CrossRefGoogle Scholar
Mullins, C.E. 1977. Magnetic susceptibility of the soil and its significance in soil science: A review. Journal of Soil Science 28. 223246.Google Scholar
Newbould, P., Floate, M.J.S. 1978. Agroecosystems in the U.K.. In “Cycling of Mineral Nutrients in Agricultural Ecosystems.” Frissel, M.J. 3370 Elsevier Amsterdam. .Google Scholar
Oldfield, F. 1978. Lakes and their drainage basins as units of sediment based ecological study. Progress in Physical Geography 1. 460504.CrossRefGoogle Scholar
Oldfield, F., Appleby, P.G., Battarbee, R.W. 1978a. Alternative 210Pb dating: results from the New Guinea Highlands and from Lough Erne, N. Ireland. Nature (London) 271. 339342.CrossRefGoogle Scholar
Oldfield, F., Dearing, J.A., Thompson, R., Garrett-Jones, S.E. 1978b. Some magnetic properties of lake sediments and their possible links with erosion rates. Polskie Archiwum Hydrobiologii 25. 321331.Google Scholar
Oldfield, F., Thompson, R., Barber, K.E. 1978c. Changing atmospheric fallout of magnetic particles recorded in recent ombrotrophic peat sections. Science 199. 679680.CrossRefGoogle ScholarPubMed
Pennington, W., Cambray, R.S., Fisher, E.M. 1973. Observations on lake sediments using fallout Cs-137 as a tracer. Nature (London) 242. 324326.CrossRefGoogle Scholar
Pennington, W., Haworth, E.Y., Bonny, A.P., Lishman, J.P. 1972. Lake sediments in northern Scotland. Philosophical Transactions of the Royal Society B 264. 191294.Google Scholar
Pentecost, A., Happey-Wood, C.M. 1978. Primary production studies in two linked but contrasting Welsh lakes. Freshwater Biology 8. 924.Google Scholar
Roberts, A.R. 1959. Ecology of human occupation and land use in Snowdonia. Journal of Ecology 47. 317323.CrossRefGoogle Scholar
Sanger, J.E., Gorham, E. 1972. Stratigraphy of fossil pigments as a guide to the postglacial history of Kirchner Marsh, Minnesota. Limnology and Oceanography 17. 840854.CrossRefGoogle Scholar
Sly, P.G. 1978. Sedimentary processes in lakes. In “Lakes: Chemistry, Geology, Physics.” Lerman, A. 6584 Springer-Verlag New York.Google Scholar
Thompson, R., Battarbee, R.W., O'Sullivan, P.E., Oldfield, F. 1975. Magnetic susceptibility of lake sediments. Limnology and Oceanography 20. 687698.CrossRefGoogle Scholar
Thompson, R., Morton, D.J. 1979. Magnetic susceptibility and particle size distribution in recent sediments of the Loch Lomond drainage basin, Scotland. Journal of Sedimentary Petrology 49. 801818.Google Scholar