Other
Scientific paper
Aug 1985
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1985gecoa..49.1753c&link_type=abstract
Geochimica et Cosmochimica Acta, vol. 49, Issue 8, pp.1753-1764
Other
5
Scientific paper
The accumulation and mobility of Fe, Mn, Al, Cu, Ni and Pb in the sediments of two lakes (Clearwater, pH 4.5; and McFarlane, pH 7.5) near Sudbury, Ontario have been investigated. The Al, Cu and Ni concentrations are expectedly relatively high in the overlying waters of Clearwater Lake and much lower for Al and Cu in McFarlane Lake. The low trace metal concentrations found in the anoxic porewaters of Clearwater Lake could be explained by a sharp increase in porewater pH concomitant with SO 4 2 reduction and H 2 S production within the first 1-2 cm of the sediments, which has conceivably led to the precipitation of mineral phases such as AL(OH) 3 , NiS, and CuS. In both lakes, Fe concentrations in anoxic porewaters appear to be controlled by FeS and/or FeCO 3 formation. Solubility calculations also indicate MnCO 3 precipitation in McFarlane Lake. In Clearwater Lake, however, both porewater and total Mn were relatively low, a possible result of the continuous loss of Mn(II) through the acidic interface. It is suggested that upwardly decreasing total Mn profiles resulting from the removal of Mn from the top sediment layers under acidic conditions may constitute a reliable symptom of recent lake acidification. The downward diffusion of AI, Cu and Ni from the overlying water to the sediments has been estimated from their concentration gradients at the interface and compared to their total accumulation rates in the sediments. In both lakes the diffusion of Al is negligible compared to its accumulation rate. However, diffusion accounts for 24-52% of the accumulation of Cu in the sediments of Clearwater Lake, but appears negligible in McFarlane Lake. The downward diffusive flux of Ni is important and may explain 76-161% of the estimated Ni accumulation rate in Clearwater Lake, and 59% in McFarlane Lake. The porewater Cu and Ni profiles suggest that the subsurface sedimentary trace metal peaks observed in Clearwater Lake (as in other acid lakes) may not be caused by sediment leaching or by a recent reduction in sedimentation but may have a diagenetic origin instead. Diffusion to the sediments thus appears to be an important and previously overlooked trace metal deposition mechanism, particularly in acid lakes.
Carignan Richard
Nriagu Jerome O.
No associations
LandOfFree
Trace metal deposition and mobility in the sediments of two lakes near Sudbury, Ontario does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Trace metal deposition and mobility in the sediments of two lakes near Sudbury, Ontario, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Trace metal deposition and mobility in the sediments of two lakes near Sudbury, Ontario will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-753394