Stratigraphical and ecological significance of Early Eocene radiolarians from the Subsilesian Series, Polish Flysch Carpathians

Abstract

Znaczenie stratygraficzne i ekologiczne wczesnoeoceńskich radiolarii serii podśląskiej, Polskie Karpaty fliszowe Variegated shales in the Early Eocene hemipelagic deposits of the Subsilesian series, Polish part of the Western Carpathians, have yielded rich siliceous microfossils comprising abundant radiolarians and rare diatoms. Forty-three radiolarian taxa have been recognised. One new radiolarian species, Amphisphaera subsilesianensis n. sp. was described. The assemblage represents the Phormocyrtis striata striata radiolarian Zone of the tropical oceans. The deposits investigated have also yielded abundant agglutinated foraminifera which correlate with the lower Eocene Saccamminoides carpathicus foraminiferal Zone. The radiolarian assemblage comprises a low content of taxa characterising cool, oligotrophic water masses which also occur in the upper Paleocene deposits of the Subsilesian series. Most part of the assemblage is represented by abundant radiolarian species characteristic of tropical domain, which may indicate the incursion of warm water masses into the Subsilesian Basin during the Early Eocene Climatic Optimum Period.