THE BENTHIC FORAMINIFERA RECORD AND THE CLIMATE FLUCTUATIONS WITHIN THE TEMPERATE WESTERN PANGAEA TROPICAL SHELVES

Benthic foraminifera including fusulinids (symbiont-bearing benthic foraminifera) are among the best indicators of paleoclimate and paleogeography in the Carboniferous and Permian. The dynamics of distribution of benthic foraminifera in space and time constrain important tectonic and climatic events at a global scale. The North American shelves during Pennsylvanian and Permian time even being geographically within the tropical belt characterized by permanent temperate environments with significantly lower foraminifera diversification and rare occurrences of warm water Tethyan forms. The temperate water environments allowed to document warming episodes that associated with abrupt immigration of warm-water and exotics in the area taxa that earlier evolved elsewhere. Several warming and cooling episodes are described and discussed. The differences of taxonomic changes in each event could potentially be used for provisional estimation of the changes degree. The occurrences of the exotic to North America forms during warming episodes are always delayed depending on a scale and the intensity of the worming episodes. The cooling events associated with decreasing of taxonomic diversity and appearances of endemic forms characteristic for temperate water provinces only. The occurrence of these forms in Boreal and North American provinces appears to be isochronous as their environments are uniform and thus stimulates the uniforms and isochronous distribution.