Use of 210Pb dating models for estimating sedimentation rate of a typical sediment core taken in the Ba Lat coastal area (Red River)
Main Article Content
Abstract
Sediment cores were taken in the coastal area of Ba Lat estuary (Red River), in the Xuan Thuy national park. Each core was cut into slices of 4 cm in thickness, numbered from top to bottom and then analyzing for radionuclides (226Ra, 137Cs and 210Pb). Computational dating models were used to determine the age and sedimentation rate for each sediment core. This report presents the results of applying computational models to the sediment core BL13 that could provide a general methodology for determining the age and the sedimentation rate of the sediment cores taken in the coastal area of Ba Lat estuary. Results show that Constant rate of supply (CRS) model is probably the best model for determining the sedimentation rate. For the sediment core BL13, the use of the Composite model by adjusting the results of the CRS model in combination with the time marker of August 1971 (the time of the historical flood event on the Red River) seems to give the most reasonable results. The average sedimentation rate at the BL13 site before 1960 was about 0.5 cm/year. The rate had increased significantly from 1960, up to the highest value of 1.5 cm year-1 in the 1970s and then decreased to about 1.0 to 1.2 cm/year from the 1980s to the present. The change in the sedimentation rate could be caused by the main flow changes and large floods of the Red River from 1960 to 1980.
Article Details
Keywords
Ba Lat estuary, 210Pbex, CIC, CFCS, CRS, Composite Model
References
[2]. Nobi E.P., Dilipan E., Thangaradjou T., Sivakumar K., Kannan L. “Geochemical and geo-statistical assessment of heavy metal concentration in the sediments of different coastal ecosystem of Andaman Islands, India”, Estuarin, Coastal and Shelf Science, 87, 253-264, 2010.
[3]. Buccolieri A., Buccolieri G., Cardellicchia N. “Heavy metals in marine sediments of Taranto Gulf (Ionian Sea, Southern Italy)”, Marine Chemistry, 99, 227-235, 2006.
[4]. Farmer J.G. “Metal Pollution in Marine Sediment Cores from the West Coast of Scotland”, Marine Environmental Research, 8, 1-28, 1983.
[5]. Sanchez-Cabeza J.A., Ruiz-Fernandez A.C. “210Pb sediment radiochronology: An integrated formulation and classification of dating models”, Geochimica et Cosmochimica Acta, 82, 183–200, 2012.
[6]. Appleby P. G. “Chronostratigraphic techniques in recent sediments”, In: Tracking Environmental Change Using Lake Sediments, vol. 1 (eds. W. M. Last and J. P. Smol), 171– 201. Basin Analysis, Coring and Chronological Techniques. Kluwer Academic Publishers, Dordrecht, The Netherlands, 2001.
[7]. Ligeroa R.A., Barreraa M., Casas-Ruiza M., Salesb D., López-Aguayoc F., “Dating of marine sediments and time evolution of heavy metal concentrations in the Bay of Ca´diz, Spain”, Environmental Pollution, 118, 97-108, 2002.
[8]. Fukue M., Nakamura T., Kato Y., Yamasaki S. “Degree of pollution for marine sediments”, Engineering Geology, 53, 131-137, 1999.
[9]. Zourarah B., Maanan M., Carruesco C., Aajjane A., Mehdi K., Freitas M.C. “Fifty-year sedimentary record of heavy metal pollution in the lagoon of Oualidia (Moroccan Atlantic coast)”, Eustuarine, Coastal and Shelf Science, 72, 359-369, 2007.
[10]. Mil-Homens M., Stevens R.L., Boer W., Abrantes F., Cato I. “Pollution history of heavy metals on the Portuguese shelf using 210Pb-geochronology”, Science of the Total Environment, 367, 466-480, 2006.
[11]. Tran Thi Thanh Nhan, Tran Nghi, Tran Ngoc Dien, Dinh Xuan Thanh, Tran Thi Dung, Nguyen Thi Phuong Thao, Dinh Xuan Truong,
Do Manh Tuan, Doan Dinh Lam.“The Holocene - Present Shoreline Migration off Thai Binh – Nam Dinh in Relation to Evolution of Deltaic Lobes and History of the So River”, VNU Journal of Science: Earth and Environmental Sciences, 34 (4), 2018. Available at:
[12]. Nhon Dang Hoai, Thanh Tran Duc, Huy Dinh Van, Hai Phan Son, Ha Nguyen Manh, Lan Tran Dinh, Duan Xiaoyong, Ve Nguyen Dac “Sedimentation Rates and Heavy Metal Concentrations in the Tidal Flats of North Vietnam”, Pol. J. Environ. Stud., 28 (5), 3721-3733, 2019.
[13]. Van Santen P., Augustinus P.G.E.F., Janssen-Stelder B.M., Quartel S., Tri N.H. “Sedimentation in an estuarine mangrove system”, Journal of Asian Earth Sciences, 29, 566–575, 2007.
[14]. van den Bergh G.D., Boer W., Schaapveld M.A.S., Duc D.M., van Weering, Tj.C.E. “Recent sedimentation and sediment accumulation rates of the Ba Lat prodelta (Red River, Vietnam)”, Journal of Asian Earth Sciences, 29, 545–557, 2007.
[15]. Martin P. & Hancock G. “Routine analysis of naturally occurring radionuclides in environmental samples by alpha-particle spectrometry”, Research Report 7, Supervising Scientist for the Alligator Rivers Region, 1992.
16]. Szarlowicz, K. “Optimization of the radiochemical procedure of 210Po determination in small amounts of sediment samples”, Int. J. Environ. Sci. Technol., 16, 5735–5740, 2019.
[17]. De Corte F., Umans H., Vandenberghe D., De Wispelaere A., Van den haute P. “Direct gamma-spectrometric measurement of the 226Ra 186.2keV line for detecting 238U/226Ra disequilibrium in determining the environmental dose rate for the luminescence dating of sediments”, Appl. Radiat. Isot., 63(5), 589–598, 2005.