Manganese profiles in freshwater mussel shells

The heavy ion microprobe in combination with particle-induced X-ray emissio n was used to measure the distribution of manganese in freshwater mussel sh ells (Hyridella depressa) from the Nepean river in south-eastern Australia. Close to the ventral edge, bands with an elevated manganese content have b een detected. These are correlated with growth bands in the mussels contain ing increased amounts of organic material, relative to the calcium carbonat e matrix. Calcium minima, which were correlated to the annual growth rings, were measured close to the umbo region of the shells. Crown Copyright (C) 2001 Published by Elsevier Science B.V. All rights reserved.