Permian paleogeographic reconstruction of the supercontinent Pangea, with superimposed paleoclimatic/biome regions based on fossil plant and lithostratigraphic indicators. Also shown is the distribution of calcium carbonate-bearing Permian-Triassic paleosols that are typically interpreted as indicators of arid to semiarid paleoclimate (denoted by latitudinal span marked by 'Arid to Semi-Arid'). Modified after Rees et al. (2002). 

Contexts in source publication

Context 1

... (South America, Africa, India, Australia, and Ant- arctica) moved northward, and Laurasia (North America, Europe, and incipient elements of Asia) moved southward until they col- lided near the equator during the Early Carboniferous ( Scotese et al., 1979). The collision of Gondwana and Laurasia initiated the assembly of the supercontinent Pangea; a horseshoe-shaped super- continent straddling the equator and extending from southern-to northern-polar latitudes (Figs. 1, 5). Climate-sensitive lithostrati- graphic indicators suggest that as Pangea assembled and moved toward its zenith in Triassic time, zonal (Hadley-type) atmospheric circulation was replaced by monsoonal circulation as large low- pressure systems developed over the low-mid-latitude regions of the supercontinent during the summer months. These changes in atmospheric circulation resulted in aridification of most of the equa- torial region, with reverse wind flow and higher precipitation devel- oping over western equatorial Pangea ( Kutzbach and Gallimore, 1989;Parrish, 1993). The low mid-latitudes became increasingly humid and seasonal as megamonsoonal circulation strengthened, and these regions experienced summertime low-pressure cells and seasonal precipitation. The MAP estimates presented here support the general concept of megamonsoon development in early Perm- ian to Early Triassic times, with high rainfall indicated in western equatorial Pangea in the early Permian, and in the late Permian- Early Triassic, increasingly arid conditions in the tropics and a tran- sition toward higher rainfall in the subtropics and ...

Context 2

... Series S (z) ppmv PCO 2 @15 C PCO 2 @25 C PCO 2 @35 C PCO 2 @45 C Aco 1000 325 410 494 579 Aco 2500 813 1025 1236 1447 Ager 1000 1 82 162 243 Ager 2500 2 In these respects, the vast majority of the variability of soil cal- cite d 13 C values, and the observed D 13 C cc-om range of the modern California soil data set, reflect changes in soil-respired CO 2 con- centrations across the recent landscapes at the time of calcite crystallization and not global atmospheric CO 2 changes ( Tabor et al., 2013b). Yet, this data set documents a range of D 13 C cc-om values such that, under the prescribed conditions of soil-respired pCO 2 for soils ( Breecker et al., 2009) and paleosols (Breecker et al., 2010), correspond to a range of atmospheric pCO 2 values ranging from less than 100 to 2200 ppm V may be estimated, a range nearly equivalent to atmospheric pCO 2 estimates for the entire Phanerozoic as estimated in Breecker and others (2010). Based upon the evidence presented herein and in previous stud- ies (Tabor et al., 2013b), we assert that, in most instances, D 13 C cc-om value is a much more sensitive and dynamic proxy of soil-derived pCO 2 variations than atmospheric pCO 2 ...

Context 3

... the past few decades, significant advances have been made in our knowledge of Permian-Triassic terrestrial climate evolution across northern mid-latitude ( Newell et al., 1999;Rees et al., 2002), equatorial (e.g., Parrish et al., 1982Parrish et al., , 1993Ziegler et al., 2003;Tabor and Monta~ nez, 2004;DiMichele et al., 2006DiMichele et al., , 2009Schneider et al., 2006), and extreme southern mid-latitude and polar (Wopfner and Kreuser, 1986;Smith, 1995;Retallack, 1999;Wopfner, 2002;Isbell et al., 2003;Retallack et al., 2006;Fielding et al., 2008) landscapes. Permian-Triassic paleoclimate history from south-central Pangean regions, including sub-Saharan Africa and northern South America (Fig. 1), remains especially poorly known (e.g., Rees et al., 2002; Ricardi-Branco, 2008;Tabor et al., 2011;Smith et al., 2015;Looy et al., 2016;Milleson et al., 2016). This lack of knowledge reflects, in large part, a lack of Permian- aged sedimentary rocks preserved and identified in these regions. In aggregate, paleoclimatic data suggest a nearly global pattern of aridification and warming of low latitudes through most of the Permian, until regional pockets of humidity reemerged at some point in the Early Triassic (Parrish, 1993;Tabor and Monta~ nez, 2005;Tabor et al., , 2013aTabor et al., , 2013cGulbranson et al., 2015;Michel et al., 2015;Milleson et al., ...

Context 4

... is a term that is commonly used in Permian-Triassic pale- oclimate reconstructions (Valentine, 1973;Parish, 1982;Ziegler et al., 2003;Tabor and Montanez, 2004;Tabor et al., 2007;, but this term is overly general and ambiguous. The attribution of 'arid' paleoclimate has been traditionally based on the occurrence of climate-sensitive lithologies, such as evapor- ites, eolianites, and certain paleosol morphologies (Calcisols, Gyp- sisols; Mack et al., 1993), which are known to be associated with arid climate in modern depositional environments but are by no means exclusive to them. These sedimentary climate indicators are most useful for providing an upper limit of paleoprecipitation (Parish, 1991;Patzkowsky et al., 1991;Ziegler et al., 2003;Sheldon and Tabor, 2009;Tabor et al., 2011) rather than delineating 'how arid' or 'how dry' a particular paleo- environment may have been (e.g., Ziegler et al., 2003;Tabor et al., 2007;. For example, upper Perm- ian and lower-Middle Triassic terrestrial strata of Pangea preserve carbonate-bearing paleosol profiles (Calcisols; sometimes called calcretes) between »40 N (e.g., Kazahkstan plate; Yang et al., 2007; Fig. 1) and »60 S paleolatitude (e.g., South Africa; Smith, *Corresponding author. Color versions of one or more of the figures in the article can be found online at www.tandfonline.com/ujvp. 1995; Fig. 1). In every instance, these paleosols have been inter- preted to indicate semiarid to hyperarid paleoclimate (e.g., Steel, 1974;Loope, 1985;Smith, 1995;Kessler et al., 2001;Mack and Dinterman, 2002;Tabor andMonta~ nez, 2002, 2004;Tramp et al., 2004;Tabor et al., 2007;Yang et al., 2007;Mack et al., 2010). However, these field-scale indicators of dry climate do not make clear, by themselves, which carbonate-bearing soils formed under more arid conditions than ...

Context 5

... is a term that is commonly used in Permian-Triassic pale- oclimate reconstructions (Valentine, 1973;Parish, 1982;Ziegler et al., 2003;Tabor and Montanez, 2004;Tabor et al., 2007;, but this term is overly general and ambiguous. The attribution of 'arid' paleoclimate has been traditionally based on the occurrence of climate-sensitive lithologies, such as evapor- ites, eolianites, and certain paleosol morphologies (Calcisols, Gyp- sisols; Mack et al., 1993), which are known to be associated with arid climate in modern depositional environments but are by no means exclusive to them. These sedimentary climate indicators are most useful for providing an upper limit of paleoprecipitation (Parish, 1991;Patzkowsky et al., 1991;Ziegler et al., 2003;Sheldon and Tabor, 2009;Tabor et al., 2011) rather than delineating 'how arid' or 'how dry' a particular paleo- environment may have been (e.g., Ziegler et al., 2003;Tabor et al., 2007;. For example, upper Perm- ian and lower-Middle Triassic terrestrial strata of Pangea preserve carbonate-bearing paleosol profiles (Calcisols; sometimes called calcretes) between »40 N (e.g., Kazahkstan plate; Yang et al., 2007; Fig. 1) and »60 S paleolatitude (e.g., South Africa; Smith, *Corresponding author. Color versions of one or more of the figures in the article can be found online at www.tandfonline.com/ujvp. 1995; Fig. 1). In every instance, these paleosols have been inter- preted to indicate semiarid to hyperarid paleoclimate (e.g., Steel, 1974;Loope, 1985;Smith, 1995;Kessler et al., 2001;Mack and Dinterman, 2002;Tabor andMonta~ nez, 2002, 2004;Tramp et al., 2004;Tabor et al., 2007;Yang et al., 2007;Mack et al., 2010). However, these field-scale indicators of dry climate do not make clear, by themselves, which carbonate-bearing soils formed under more arid conditions than ...