Skip to Main Content

Abstract:

Chattian and Miocene coral reefs and faunas of the western France basins are reviewed within a paleogeographic context. Several new outcrops have been discovered, and extensive new and historic collections have been studied. Coral diversity was very high in the Aquitaine basin during the Chattian(1) (ca. 150 species) and a little less so during the Early Miocene (110 species); during these times, relatively small reefal buildups formed in a tropical climate. The Mid-Miocene coral faunas show a marked decrease in diversity (some 75 species in all), with "subreefal" facies in the Langhian of southwestern and northwestern France. The Upper Miocene fauna is even poorer (just about 20 species) and only known in northwestern France. Throughout the Miocene, the proportion of hermatypic taxa also decreased notably; in the coral assemblages, these species were strongly predominant from Chattian to Burdigalian. Afterwards, the ahermatypic taxa became progressively predominant. Other northeastern Atlantic areas (Portugal, Morocco) are also investigated. Some biogeographic data sketch the evolutionary trend of these coral communities. During the Chattian, an (eastern and western) Atlantic-Mediterranean bioprovince was differentiated. During the Early Miocene, this bioprovince was restricted to eastern Atlantic and Mediterranean. From the Mid-Miocene, the coral faunas were disconnected from the Mediterranean, and an impoverished eastern Atlantic bioprovince became established without real renewal. A comparison with Mediterranean reefs shows that maximum coral building took place within the Mid-Miocene in the Mediterranean realm (with continuation of reefs in the Late Miocene), instead of Chattian (and Early Burdigalian) as in the Atlantic areas.

You do not currently have access to this chapter.

Figures & Tables

Contents

GeoRef

References

Related

Citing Books via

Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal