Sedimentation of Pb-210 in Laurentian Shield Lakes

Abstract

The average annual flux of Pb-210 from the atmosphere to lake surfaces and to the bottom sediments was measured in seven small lakes located on the Laurentian Shield. Direct atmospheric fallout of Pb-210 was 136 ± 16 Bq m-2 a-1 Streams from the lakes' catchments input an additional 5 to 473 Bq m-2 a-1. Only 16 to 80 percent of the total input was found in the lake sediments. The fractional rate constant for Pb-210 sedimentation from the water column ranged from 0.25 to 5.3 per annum.

Late Holocene change in climate and atmospheric circulation inferred from geochemical records at Kepler Lake, south-central Alaska

“…Using alpha spectrometry methods as described in Cornett et al (1984), ten samples from core KL07-1 were analyzed from 0 to 15 cm, and ten samples from core KL07-2 were analyzed from 0 to 29 cm. The constant-rate-of-supply model was used for interpreting the 210 Pb data (Appleby and Oldfield 1978).…”

“…210 Pb dates from KL07-2 on the basis of the constant-rate-of-supply model provided a chronology for the last 94 years (Table 3; Fig. 4b; Cornett et al 1984). Chronology for core KL07-2 was generated using a linear interpolation between the 210 Pb dates, one calibrated radiocarbon age at the base of the core (Fig.…”

Arsenic, iron and sulfur co-diagenesis in lake sediments

“…where {As} 1850 is the average pre-1850 {As} hist at the sampling site, 210 Pb I sed is the inventory of unsupported 210 Pb in the sediment cores (Table 1) and 210 Pb I atm is the cumulative atmospheric input of 210 Pb, which was assumed to be identical to the average inventory of 210 Pb uns in soils on the Precambrian Shield in Eastern Ontario (0.44 Bq cm À2 ; Cornett et al (1984). The ratio 210 Pb I atm / 210 Pb I sed in Eq.…”

Geochemical and anthropogenic enrichments of Mo in sediments from perennially oxic and seasonally anoxic lakes in Eastern Canada

“…where 210Pb I atm is the cumulative atmospheric input of 210 Pb un in the area of study, which is assumed to be identical to the 210 Pb un inventory (0.44 Bq cm À2 ) in soils of the Precambrian Shield in Eastern Ontario (Cornett et al, 1984), and 210Pb I sed is the inventory of 210 Pb un measured in the sedimentary column at the sampling site. Such a correction implies that the processes that control Mo and 210 Pb deposition to the sediments act similarly.…”