Permo-Carboniferous climate: Early Pennsylvanian to Late Permian climate development of central Europe in a regional and global context

Abstract

A well-justified stratigraphical correlation of continental successions and new palaeogeographic reconstruction of Pangaea reveal new insights into the northern Pangaean climate development influenced by palaeogeography, palaeotopography, glacio-eustatic sealevel changes and ocean currents. The overall Permo-Carboniferous aridization trend was interrupted by five wet phases. These are linked to the Gondwana icecap. The aridization and weakening of wet phases over time were not only caused by the drift of northern Pangaea to the arid climatic belt, but also by the successive closure of the Rheic Ocean, which caused the expansion of arid/semi-arid environments in the Lower/Middle Permian. The end of the Gondwana glaciation rearranged ocean circulation, leading to a cold, coast-parallel ocean current west of northern Pangaea, blocking moisture coming with westerly winds. The maximum of aridity was reached during the Roadian/Wordian. The Trans-Pangaean Mountain Belt was non-existent. Its single diachronous parts never exceeded an average elevation of 2000 m. The maximum elevation shifted during time from east to west. The Hercynian orogen never acted as an orographic east-west barrier, and the Inter-Tropical Convergence Zone was widely displaced, causing four seasons (dry summer/winter, wet spring/autumn) at the equator and a strong monsoon system.

Callipterid peltasperms of the Dunkard Group, Central Appalachian Basin

“…These oscillations are, however, superimposed on a shift to "drier" conditions in equatorial Pangea during later Pennsylvanian time (Roscher and Schneider, 2006;Tabor and Poulsen, 2008), when the Monongahela Formation and lower Dunkard were deposited. A consequence of this longer-term shift is that in continental basins of the US and Europe the Pennsylvanian-Permian boundary, no matter how it is defined (paleontologically or by absolute age dates), is lithologically gradational, to the point of being described as "indistinct".…”

“…Plant distribution, both of individual species and of species pools, strongly reflects the interplay of climatic and local habitat conditions (e.g., see many references to this in DiMichele et al, 2008;Roscher and Schneider, 2006). As a consequence, it is essential that biostratigraphic schemes be established on the basis of species pools with ecological and evolutionary continuity in space and time, the plants living under similar climatic and environmental conditions.…”

Late Paleozoic continental warming of a cold tropical basin and floristic change in western Pangea

“…The absence of a clear hiatus at the Pennsylvanian-Permian boundary is seen in other terrestrial sections from Western Europe (Roscher and Schneider, 2006), through the Dunkard Group in the Appalachians (Fedorko and Skema, 2011;Martin, 1998), to the southwestern United States (Condon, 1997). In mixed terrestrialmarine sections, such as in the Midcontinent United States (Sawin et al, 2006), there is evidence of continuous cyclothemic deposition across the boundary, again not indicative of a major physical hiatus (Olszewski and Patzkowsky, 2003;Mazzullo et al, 2007).…”

On the fundamental difference between coal rank and coal type

“…The physical and biological dynamics of this time were superimposed on the complex low-latitude landscape where a vast amount of Pennsylvanian peat formed (e.g., Cecil et al, 2003a;Cleal et al, 2009;Gastaldo et al, 1993;Greb et al, 1999Greb et al, , 2003Greb et al, , 2008Staub, 2002). The Euramerican portion of this landscape included the Variscan-Appalachian mountain ranges, subparallel to the equator (Opluštil and Cleal, 2007), creating large areas of both cratonic and intermontane basins for peat formation in Europe and southeastern Canada (Bashforth et al, 2010;Calder, 1994;Opluštil and Cleal, 2007;Piedad-Sánchez et al, 2004;Roscher and Schneider, 2006), and the large cratonic basins in the United States, in which many of the major coal beds, particularly in the Middle Pennsylvanian, developed on flat landscapes often of vast areal extent (Belt et al, 2011;Calder and Gibling, 1994;Cecil et al, 1985Cecil et al, , 2003bGreb et al, 2003;Heckel, 1995Heckel, , 2008Staub, 2002). Climatic fluctuations, sea-level fluctuations, changes in siliciclastic sediment flux, and the formation of peat and limestone, were not independent variables (Cecil and Dulong, 2003).…”