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Lago Grande di Monticchio, southern Italy: a long record of environmental change illustrated by sediment geochemistry

1994; Elsevier BV; Volume: 118; Issue: 1-4 Linguagem: Inglês

10.1016/0009-2541(94)90179-1

1872-6836

Christian Robinson,

Paleontology and Stratigraphy of Fossils

Bulk geochemical analysis has been carried out on a 51-m sediment core from Lago Grande di Monticchio in southern Italy. The record, which may extend from the present back through more than one glacial cycle, displays major variations in indicators of palaeoproductivity such as organic carbon and biogenic silica. The most prominent change occurs at the Holocene boundary. Lower in the sequence, zones of moderately enhanced productivity highlight either interstadial or interglacial periods. C/N ratios and hydrogen indices provide possible indications of the sources and diagenetic state of the bulk organic matter, but must be interpreted carefully as it is difficult to isolate the effects of these two factors. Changes in the clastic fraction (e.g., Na/Al ratio) suggest that tephra deposition in the lake and its catchment has significantly altered the sedimentation. This may also have influenced the biological productivity of the system.