PERMO-CARBONIFEROUS CLIMATE OF THE LODEVE BASIN, FRENCH MASSIF CENTRAL: RELATION TO OTHER PALEO-EQUATORIAL RECORDS, AND THE PENULTIMATE ICEHOUSE-GREENHOUSE TRANSITION

Paleoclimate indicators and geochemical proxy data will be presented from the Late Pennsylvanian through Permian low-latitude, tropical terrestrial sedimentary strata of the Lodeve basin, French Massif Central. These strata range temporally from the Kasimovian (Stephanian B) to the Lopingian (Zechstein), with short regional unconformities in the Asselian (Lower Rotliegend) and the Upper Sakmarian/Lower Artinskian (Upper Rotliegend 1; Schneider et al., 2006). Field-scale paleoclimate indicators include (1) paleosol morphologies of Histosols, Vertisols, Calcisols, and Gypsisols, (2) evaporites and (3) fossil floras. Laboratory-based paleoclimate indicators include X-ray diffraction identification of climate-sensitive clay mineralogies such as kaolinite, smectite, illite and chlorite. The Upper Carboniferous strata (Kassimovian-Ghzelian) are dominated by indicators of a humid, nearly everwet climate including Histosols and fossil lycopsids. Early Permian (upper Asselian-Sakmarian, Artinskian) strata are dominated by indicators of seasonal, sub-humid to semi-arid climate such as calcic Vertisols, Calcisols, and floras dominated by conifers. Middle to early Late Permian (Guadalupian – Wuchiapingian) strata are dominated by indicators of non-seasonal, semi-arid to arid climate including Calcisols, Gypsisols and thinly bedded evaporites. Late Permian (Wuchiapingian – Changsingian) strata are dominated by indicators of strongly seasonal, semi-arid climate including calcic Vertisols, Gypsisols and possible magadiite cherts. This stratigraphic record of paleoclimatic change from eastern Tethys will be compared with other contemporaneous, low-latitude tropical records from western Pangea (southwest U.S.A.) Central Pangea (Canadian Maritimes, Appalachian basin, Tim Mersoi basin, Niger), other European records, and eastern Tethys (Kazakhstan, China) to delineate trends, if any, with independent high-latitude records of glaciation.