210Pb determination

A series of gravity cores was collected inside the inlet and at a control station located some 5 km north of the inlet in Port Orchard Passage, as shown in figure 2. The sedimentation rates as determined by 210Pb are shown in figure 4a where a least squares fit of the data gives an average sedimentation rate of... 

The 210Pb inventory in the sediments was calculated in a similar way to the 239,240pu method described previously, but 1 cm increments were used in determining the integrated deposition. The deposition rate of the 210Pb for each core was determined as the product of the integrated deposition and the radioactive decay constant, (A. =. 0311 yr-1). Since the unsupported 210Pb (t ... 

El-Daoushy, M. F. A. F., The determination of 210Pb and 226Ra in lake sediments and dating application, Uppsala, Sweden report UUIP-979 (1976). 

The age-determination results by using 210Pb and 137Cs for the sedimentary columns of the alluvia beds along the trunk stream and main tributaries of the Anhui section of Yangtze River show that the variations of the contents of Cd and other heavy metals were basically corresponding closely to major historical events, say the establishment of PRC, the exercise of the policy of reformation and opening and the course of extensive industrialization, etc. 

This model requires an excess of sulfate over reducible carbon. Concentrations may be measured in solutions squeezed from sediment cores, diffusion coefficients are known from standard chemical data tables and sedimentation rates determined from 14C, 210Pb, or 230Th dating. Therefore, this model finds its best use in the recovery of the kinetics of organic matter decay. A discussion of this and similar equations and numerical applications may be found in Berner (1980). 

Separation and Determination of Polonium 210Po and Lead 210Pb... 

Takizawa, Y., L. Zhao, M. Yamamoto, T. Abe, and K. Ueno. 1990. Determination of 210Pb and 210Po in human tissues of Japanese. J. Radioanal. Nucl. Chem. 138 145-152. 

Much of the work to date in estuaries and adjacent marsh/shelf environments using 210Pb has been to determine sediment accumulation and accretion rates (Armentano and Woodwell, 1975 Krishnaswami et al., 1980 Church et al., 1981 Kuehl et al., 1982 Olsen et al., 1985 Paez-Osuna and Mandelli, 1985 McKee et al., 1986 Lynch et al., 1989 Bricker-Urso, 1989 Moore, 1992 Smoak et al., 1996 Dellapenna et al., 1998, 2001 Benoit, 2001 Corbett et al., 2003). Lead-210 is considered to be a reliable method for dating sediments deposited over the last 100 to 110 y (Krishnaswami et al., 1971). In the absence of bioturbation/mixing the activity gradient of excess 210Pb in sediments, which is the net result of accumulation and radioactive decay, can provide information on the sedimentation rate of recent sediments. Unfortunately, in many... 

McKee et al. (1983) demonstrated that 234Th and 210Pb can be used to determine 100-d deposition and 100-y accumulation rates, respectively, near the mouth of the Yangtze River estuary (China). The short-term deposition rate was approximately 4.4 cm per month (figure 7.16a) versus accumulation rates of approximately 5.4 cm y-1 (figure 7.16b), integrated over one century. Thus, the stratigraphic record over the last 100 y is incomplete... 

Lead-210 is produced by radioactive decay of 222Rn and can enter estuaries as a dissolved/complexed ion or in association with particles from the ocean, river, and atmosphere. Much of the work to date in estuaries and adjacent marsh/shelf environments using 210Pb has been to determine sediment accumulation and accretion rates. 

Armentano, T.V., and Woodwell, G.M. (1975) Sedimentation rates in a Long Island marsh determined by 210Pb dating. Limnol. Oceanogr. 20, 452-455. 

DeMaster, D.J., and Cochran, J.K. (1982) Particle mixing rates in deep-sea sediments determined from excess 210Pb and 32Si profiles. Earth Planet. Sci. Lett. 61, 257-271. 

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