Palynological study of the Late Quaternary of Loyalty Basin (SW Pacific)

Abstract

Palynological studies have been carried out on two cores from the Loyalty Basin, one near the New Caledonia shore (KK 231) and the other near Lifou Island (KK 88). The sediments under consideration cover the interval from the Last Interglacial to the Holocene. All the samples revealed the mixing of continental and marine palynomorphs varying with carbonate sediment variations that are themselves correlated with the Late Quaternary sea level fluctuations. Dinoflagellate cysts and foraminifera are the dominant components of the marine fraction. Dinoflagellate cysts reached their maximum abundance during the high sea-level of the Last Interglacial, while foraminifera were most abundant during the onset of the Holocene transgression. Changes in the continental palynomorphs can also be observed; these seem to be linked to sea-level variations, modifying conditions of production, transport and deposition, and to the effects of climatic changes on the community structure of terrestrial vegetation.