MIOSPORE STRATIGRAPHY, THE TOOL TO LINK LATE DEVONIAN CONTINENTAL MACROFAUNA, MACROFLORA AND EVENTS TO THE STANDARD CONODONT ZONATION

Accurate Late Devonian biostratigraphy is based on conodonts, marine microfossils. Dating non-marine deposits which do not contain conodonts, depends therefore on miospores, which are produced in huge quantities by terrestrial plants and are often abundantly dispersed in contemporaneous marine sediments. Most of the correlation between conodont and miospore stratigraphies has been established in Western Europe, notably in the Ardennes-Rhine area. Lack of localities with rocks containing both spores and conodonts has hampered corresponding correlation in North America. Exploration to find more such outcrop is underway.

Miospore stratigraphy is sometimes hampered by some provincialism of the parent plants. We give some examples of correlations within the Cymbosporites Realm, which encompasses southern Euramerica and western Gondwana. across arid, warm- and cool-temperate climates.

Among the detailed correlations considered are these: -the Hangenberg Crisis in the Middle praesulcata Zone (Latest Famennian) from arid equatorial (Greenland) to warm temperate subtropical Pocono Fm (Pennsylvania) and the glacial events in Western Gondwana (South America); - the Belgian Middle and Late Famennian with Catskill Fm (Pennsylvania to Virginia) and the Protosalvinia deposits of the Amazon Basin (Brazil); - and the Latest Frasnian mid Famennian from Western Europe to New York State and the Amazon Basin (the Barreirinha Fm, Brazil). The dating of the earliest Tetrapods, the Lower Famennian flora crisis, the regionalism of Archaeopteris diversity, and development of the lycophytes around Rhacophyton peat-bogs will be emphasized.