EU, 4th Framework Programme, Climate and Environment, ENV4-CT97-0557

Co-ordinator: Professor Michael O’Connell

The project aimed on a Holocene palaeoenvironmental and palaeoclimatic reconstruction for the western margin of Europe on the basis of the lake sediment record of the brackish karst Lake An Loch Mór (Island of Inish Oirr, Galway Bay). The modern lake receives diurnal sub-surface infiltration of sea water. The Carboniferous limestone of the catchment is nearly without siliciclastic soil over and favours the seepage of rainfall. This makes the sediments of the lake to a sensitive natural archive for the dissolved influx of elements and aeolian input.

Our contribution included detailed geochemical analyses of the lake sediments and a lead isotope study. On the basis of these data, we inferred (i) the onset of diurnal sea water infiltration related to the postglacial sea level rise, (ii) long-term variations in the freshwater inflow from the catchment, (iii) variations in the aeolian influx of aluminium silicates of remote provenance, and (iv) influx of anthropogenic Pb during the Roman Period. The corresponding lead ore mining sites were constrained on the basis of combined chemical and isotope mass budgets.

References

Schettler, G.; Romer, R. L. (2006): Atmospheric Pb-pollution by pre-medieval mining detected in the sediments of the brackish karst lake An Loch Mór, western Ireland. Applied Geochemistry, 21, 1, 58-82.

Schettler, G.; Romer, R. L.; O'Connell, M.; Molloy, K. (2006): Holocene climatic variations and postglacial sea-level rise geochemically recorded in the sediments of the brackish karst lake An Loch Mór, western Ireland. Boreas, 35, 4, 674-693.