Palynology and palaeoenvironments of the silurian coosglass slate and ferriter's cove formations in the dunquin inlier (dingle Peninsula, Ireland)

This study documents the first palynological data from the Silurian of the Dunquin Inlier of the Dingle Peninsula and focuses on the lower part of the succession. The previously un dated Coosg lass Slate Formation contains a low diversity Llandovery to early Wen lock acritarch as semblage, con firming the previously enigmatic Coosglass Slate Formation as the oldest for ma tion in the Silurian succession. The lithofacies and acritarch biofacies suggest the mudstones of the Coosglass Slate Formation rep re sent a low energy, off shore, muddy shelf palaeo environment. The Ferriter's Cove Formation, a succession of five off shore to tidal-flat regressive ma rinecycles yielded more diverse palynological as semblages. Acritarchs and cryptospores from the Ferriter's Cove Formation confirm a Wen lock (Homerian) age for this formation. The integration of palynological and sedimentological data from four of the off shore to tidal-flat regressive cycles reveals three con sis tent palynomorph distribution trends: (1) off shore and shoreface depositional facies contain the most diverse palynological as semblages in which acritarchs with long and ramified processes dominate; (2) back-barrier tidal-flat facies are character-ized by terrestrially de rived palynomorphs, particularly cryptospores, together with a re stricted acritarch assemblage of mainly micrhystrid and veryhachid forms with small simple processes; (3) back-barrier lagoonal facies with patch reefs are dominated by the sphaeromorph acritarch Leiosphaeridia.