LATE FRASNIAN-FAMENNIAN CLIMATES BASED ON PALYNOMORPH ANALYSES AND THE QUESTION OF THE LATE DEVONIAN GLACIATIONS

Abstract

Palynomorph distribution in Euramerica and western Gondwana, from the Latest Givetian to the Latest Famennian, may be explained, to some extent, by climatic changes. Detailed miospore stratigraphy dates accurately the successive steps of these changes. Interpretation is built on three postulates which are discussed: Euramerica at slightly lower latitudes than generally accepted by most paleomagnetic reconstructions; a conodont time-scale accepted as the most used available subdivision of time; and Late Devonian sea-level fluctuations mainly governed by glacio-eustasy. The Frasnian–Famennian timescale is also evaluated.