2008 Joint Meeting of The Geological Society of America, Soil Science Society of America, American Society of Agronomy, Crop Science Society of America, Gulf Coast Association of Geological Societies with the Gulf Coast Section of SEPM

Paper No. 7
Presentation Time: 3:20 PM

Late Paleozoic Climate: Constraints on Warming and Cooling from the benthic foraminifera record

DAVYDOV, Vladimir, Department of Geosciences, Boise State University, 1910 University Drive, Boise, ID 83725, vdavydov@boisestate.edu

Benthic foraminifera including fusulinids (symbiont-bearing) are among the best indicators of paleoclimate and paleogeography in the Carboniferous and Permian. The Cenozoic record of benthic foraminifera diversity shows a strong correlation with well studied climatic changes for that time and this model of the interaction between tropical benthic foraminifera and climate is applied for the Late Paleozoic. Late Paleozoic is commonly regarded as a time of global greenhouse-icehouse climate transition. The most recent data suggest multiple phases of glaciation-deglaciation processes, although the number of these phases and their age constraints are debated. Marine biotas are sensitive to local, regional or global environmental changes and the exceptionally well studied benthic foraminifera are among the best indices of paleoenvironments. Two antitropical transitional realms (or provinces) periodically appear in the north and south from Tethyan realm in respond of cooler-water environments and possess specific and low diversity taxonomic composition. The dynamics of distribution of benthic foraminifera in space and time constrain important tectonic and climatic events at a global scale. The diversity of benthic foraminifera in northern Pangaea during the Carboniferous and Permian time indicate several cooling and warming episodes that correspond with proposed geological and geochemical proxies of climatic variations. The late Visean, Gzhelian-Asselian and Asselian-Sakmarian transitions represent the warmest times in the Late Paleozoic based on high benthic foraminifer's diversity and reduced provincialism. Climatic changes in the late Gzhelian through early Sakmarian were sharp and frequent. Kungurian time is associated with great global reductions of fusulinid diversity and with significant global cooling that eliminated fusulinids in the Boreal realm. Climatic variations during the Guadalupian-Lopingian were much smaller in scale with three small warming peaks at latest Kungurian, Late Wordian-Capitanian, and Changsingian.