Oxygen isotopes in shells.eps

Fig. 5 d18Oar records of the four shells: a Beegden 1918 (Unio tumidus), b Bergen 1918 (U. crassus), c Vierlingsbeek 1977 (U. pictorum), d Waalwijk 1977 (U. pictorum). All shells show a truncated seasonal pattern with sharp upward pointing peaks reflecting winter growth stops and low values reflecting summer growth seasons. d18Oar data of the Bergen 1918 shell have previously been published by Verdegaal et al. (2005) From: Versteegh, E.A.A., Vonhof, H.B., Troelstra, S.R., Kroon, D., 2011. Can shells of freshwater mussels (Unionidae) be used to estimate low summer discharge of rivers and associated droughts? International Journal of Earth Sciences 100(6): 1423-1432.