lucas, s.g. and zeigler, k.e., eds., 2005, the nonmarine...

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Lucas, S.G. and Zeigler, K.E., eds., 2005, The Nonmarine Permian, New Mexico Museum of Natural History and Science Bulletin No. 30.

INTRODUCTION

Phanerozoic time is divided into three parts by mass extinctionsat the end of the Permian and Cretaceous, and the main thesis of thispaper is that the three main divisions of the Permian also are naturaldivisions punctuated by crises for life and environment. Much of myevidence comes from fossil soils (paleosols), which can furnish recordsof Permian paleoclimate of high temporal resolution. Paleosols pro-vide evidence of former precipitation from the depth of pedogenic car-bonate (Retallack, 2005), as well as from their degree of chemical weath-ering (Sheldon et al., 2002). Chemical weathering and permafrost struc-tures of paleosols can also provide evidence of paleotemperature(Retallack, 1991a-c; Retallack et al., 2003). Pedogenic clay and car-bonate nodule oxygen isotopic composition is also an indication ofpaleotemperature (Tabor et al., 2002). Carbon isotopic composition ofpedogenic nodules is an indication of atmospheric carbon dioxide lev-els (Royer et al., 2004). Additional indicators of atmospheric carbondioxide levels are the stomatal index of peltasperm seed ferns (Retallack,2002a-b). Also indicative of environmental stresses is vein density offossil leaves (Uhl and Mosbrugger, 1999; Uhl et al., 2002). These vari-ous proxies of past greenhouses are here applied to revealpaleoenvironmental changes during the Permian.

PRECIPITATION RECORDS FROM PALEOSOLS

Thousands of Permian paleosols are now known from Australia(Retallack, 1999a, b), Antarctica (Retallack and Krull, 1999), SouthAfrica (Retallack et al., 2003), Russia (Yakimenko et al., 2004), and inthe US states of Texas (Tabor and Montañez, 2004), Oklahoma (Olson1967), and Utah (Ekart et al., 1999). Depth to carbonate nodules iswell known to be related to mean annual precipitation in modern soils,with depths of about a meter common in subhumid eastern Nebraska,declining westward to depths of only a few centimeters in arid Colo-rado Springs, USA. This relationship was first discovered in the NorthAmerican Great Plains by Jenny and Leonard (1935) then amplified toa global data set by Retallack (1994, 2005). There are stringent limita-tions on its use for moderately developed soils of sedimentary or otherunconsolidated parent materials of low topographic relief (Retallack,2000), which apply to the Permian fluvial paleosols of Texa and Okla-homa studied here. Relaxation of these constraints invalidates the rela-tionship (Royer, 1999).

Geological setting—Early Permian paleosols of Texas and Okla-homa have been described by Tabor and Montañez (2004), but similarcalcareous, red paleosols are common also in the Middle and Late Per-mian of Texas (Appendix 1). A Permian-Triassic boundary sequencehas been discovered by Steiner (2001) using radiometric dating andmagnetostratigraphy in Caprock Canyons State Park, near Quitaque,Texas (Fig. 1). Precise geological age of each paleosol can be gainedfrom linear interpolation between meter level and either radiometri-

cally dated ashes (Renne et al., 1996) or paleomagnetic chrons (Steiner,2001; readjusted to the time scale of Gradstein et al. (2005). This sec-tion was fit with two separate linear regressions because it shows apronounced acceleration of sedimentation rate at the Permian-Triassicboundary (Fig. 2), like many other paleosol sequences across this bound-ary (Retallack, 1999a, Retallack and Krull, 1999; Retallack et al., 2003).Other Middle and Late Permian paleosols near Guthrie (Roth, 1945)and Robert Lee (Mear, 1961, 1963) were also dated by linear interpo-lation between paleomagnetic chrons (Steiner, 2001) with attention toradiometric dating (Renne et al., 2001). Early Permian paleosols ofTexas were dated by linear interpolation between levels correlated withthe Missourian-Virgilian boundary (-38 m in section of Hentz 1988)and the Vigilian-Wolfcampian boundary (138 m of Hentz, 1988), whichhave been radiometrically dated at 307.0 ± 3 and 302.4 ± 2.4 using U-Pb methods on pedogenic carbonate in a core in the western MidlandBasin of Texas (Rasbury et al., 1998). The Oklahoma section was datedby correlation of key horizons with those of Texas: basal WellingtonFormation (87 m) with basal Waggnoner Ranch Formation (520 m),basal Hennessey Group (254) with basal Vale Formation (750 m), andbasal Duncan Sandstone (406) with basal San Angelo Formation (998m; thicknesses from Dott, 1927; Hentz, 1988; Jones and Hentz, 1988;Nelson et al., 2001). Assigned ages are compatible with an Artinskianage of footprints in the upper Choza Formation, and Leonardian age ofammonoids and fusulinids from the Blaine and San Angelo Formations(Lucas, 2004).

Most of my record of South African paleosols came from a north-south transect examining every roadcut for 90 km along highway 29south of Beaufort West, and from the spectacular roadcuts ascending

PERMIAN GREENHOUSE CRISES

GREGORY J. RETALLACK

Department of Geological Sciences, University of Oregon, Eugene, OR 97403

Abstract—Long records of paleosols from Australia, South Africa and Texas-Oklahoma now reveal abrupt andtransient peaks of warm-wet paleoclimate at key biostratigraphic turning points of the end-Kungurian, end-Guadalupian, and end-Permian. Independent evidence from the isotopic composition of pedogenic carbonateand from stomatal index of seed ferns indicates that these were also times of high atmospheric carbon dioxide.Increased sclerophylly of plants at these times indicates peaks of environmental stress. These were also times ofelevated biotic turnover for marine invertebrates and conodonts, as well as for land plants and tetrapods. Three-fold biostratigraphic subdivision of the Permian period may reflect episodic atmospheric greenhouse crises.

FIGURE 1. Localities examined in Oklahoma, Texas, and South Africa (examinedlocalities, as open symbols, are near named locations, as solid symbols). See alsoAppendix 1, and supplementary information to Retallack et al. (2003).

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Teekloof Pass north toward Fraserburg (Retallack et al., 2003, supple-mentary information). Most of these rocks are flat-lying, but the south-ern end of the Beaufort West transect is part of the Cape Fold Belt(Toerien and Roby, 1979). My dips and strikes and their resolution forstratigraphic level of the paleosols are shown in Figure 3. Also exam-ined were Permian-Triassic boundary sections at Lootsberg Pass, CarltonHeights and near Bethulie (Retallack et al., 2003). The age of thesepaleosols was calculated by linear interpolation between meter level(Toerien and Roby, 1979; Rubidge, 1995) and radiometric dates of ashesin the Ecca Group and Dwyka Tillite (Ghosh et al., 1998; Bangert etal., 1999; Stollhofen et al., 2000), as well as three paleomagnetic chronboundaries of Ward et al. (2005; as dated by Gradstein et al., 2005).

Methods—Each local section was located with a Garmin GPSand a local section measured by the method of eyeheights (1.65 m here),with adjustments of sighting and height for dip, using a Brunton com-pass (Appendix 1). Depth to pedogenic carbonate from the top of thepaleosol (Fig. 4E), the thickness of the paleosol with carbonate nod-ules and the size of the nodules were all measured with a milliner’stape. Localities well known for vertebrate fossils were targeted for ex-amination (Olson and Beerbower, 1953; Olsen and Barghusen, 1962;Olson, 1967; Rubidge, 1995), because experience has shown that theseare commonly rich in calcareous paleosols (Retallack, 1998).

Measured sections in addition to regional overburden (fromBaumgartner and Caran, 1986: Smith et al., 1998) were used to esti-mate compaction of the paleosols, and thus reduction in depth to car-bonate, due to burial by overburden (using standard equation forInceptisols of Sheldon and Retallack, 2001). These compaction-cor-rected depths to carbonate were then placed in the predictive transferfunction for modern soils to estimate past mean annual precipitation,and its standard error (Retallack, 2005). Correction for higher thanmodern atmospheric CO

2 was not applied, but could be important. In-

crease from 2 to 11 times present level has been modeled (McFaddenand Tinsley, 1985) to increase depth to pedogenic carbonate 5 cm, re-sulting in a difference in estimated mean annual precipitation of 25mm for a carbonate depth of 50 cm and 18 mm for a carbonate depth of100 cm. Thus estimates of mean annual rainfall may have been slightlyless for a few times of short duration when atmospheric carbon dioxideis suspected to have been very high (Retallack, 2002a-b).

Results—Both the Texas-Oklahoma and South African paleosolsequences show strong increases in mean annual precipitation duringthe end-Guadalupian and end-Permian. There is also a lesser peak atthe end-Kungurian in South Africa. The Texas-Oklahoma sections show

in addition minor peaks at the end of the Asselian, Sakmarian, andArtinskian, and a pronounced pluvial at the Carboniferous-Permianboundary (Fig. 5D), which may predate the terminal Pennsylvanian(Virgilian-Wolfcampian) by a million years (Rasbury et al., 1998).

Although only paleoprecipitation data has been presented here,spikes in precipitation were also spikes in temperature. This has beenwell established at the Permian-Triassic boundary in South Africa,Antarctica and Australia from the jump in chemical weathering ofpaleosols (Retallack, 1999a, Retallack and Krull, 1999; Retallack etal., 2002b), and southward migration of low latitude plants such asLepidopteris (Retallack, 2002b), and Isoetes (Retallack, 1997b) fol-lowing extinction of cold temperate Glossopteris (Retallack, 1995).Oxygen isotopic analysis of pedogenic clays in Early Permian paleosolsof Texas also demonstrate that peaks of precipitation revealed herefrom depth to carbonate were peaks of temperature (Tabor et al., 2002).

These striking changes in paleoclimate through the Permian in-ferred from pedogenic carbonate are obvious in outcrop (Fig. 4A-B).Unlike many paleoclimatic proxies which require complex laboratoryanalyses, these observations are readily checked and reassessed in thefield.

PLANT TOLERANCE FROM LEAF SCLEROPHYLLY

A distinctive feature of fossil floras from the Blaine and SanAngelo Formations of Texas is their “Mesozoic” appearance, withstrongly sclerophyllous rather than mesic plants, few broad-leaved seedferns, and many needle-leaved conifers (Dimichele et al., 2001, 2004).Similarly, glossopterid leaves collected in Antarctica from levels corre-lated by carbon isotope chemostratigraphy with the end-Guadalupianand end-Permian (Retallack et al., 2005) have a much higher vein den-sity, and so are more sclerophyllous, than leaves at other stratigraphiclevels (Fig. 6). A comparable rise of sclerophylly was noted by McElwainet al. (1999) at the Triassic-Jurassic boundary, which they demonstratedfrom a nadir of stomatal index to be a pronounced spike in atmosphericcarbon dioxide abundance. This possibility is also examined here withmeasurements of the vein density of fossil Taeniopteris from Texas andGlossopteris from Antarctica (Fig. 5B, Appendices 2-3). Sclerophyllyof leaves is unlikely to be a direct response to elevated carbon dioxide(Uhl and Mosbrugger, 1999), but can be due to shortage of water or

FIGURE 2. Permian-Triassic boundary section from magnetostratigraphic andradiometric reinterpretation of Dewey Lake and Alibates Formations in CaprockCanyons State Park, Texas, based on date of Renne et al (1996), Steiner (2001) andGradstein et al. (2005). FIGURE 3. Structural solution for stratigraphic level of paleosol exposures in

roadcuts (open symbols) of the Permian Beaufort Group along National Route 29from Modderdrift to National Route 1 near Beaufort West. Also shown are locallithostratigraphy and vertebrate zones (Rubidge, 1995). Fold data are from my owndips and strikes, and agree with mapping by Toerien and Roby (1979).

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nutrients, increased attack by herbivores or fungi, or increased heatstress from exposure to the sun (Uhl et al., 2002). Leaf sclerophylly isan indication of an adaptive emphasis on tolerating adverse conditions,as opposed to competing for resources or emphasizing fecundity(Retallack, 2004).

Geological setting— Early Permian Taeniopteris species fromTexas represented by at least five leaves were measured in the collec-tions of the US National Museum (Appendix 2). These are from thesame stratigraphic sections as the studied paleosols of Texas (Taborand Montañez, 2004), but in gray to red sandy levee facies, and red togreen shaley lacustrine facies. Taeniopteris is a persistent but uncom-mon element of these Early Permian floras dominated by seed ferns,cordaites and conifers (Dimichele et al., 2001, 2004). The ages of thesevarious localities were calculated from their stratigraphic level usingthe same calibration used for paleosols (based on radiometric dating ofRasbury, et al., 1998).

Glossopteris leaves measured for vein density are all in collec-tions of the Condon Museum at the University of Oregon, and werecollected from measured sections at Graphite Peak, Portal Mountainand Mount Crean, Antarctica (Retallack and Krull, 1999). One leaf(F37101) from Graphite Peak and all leaves from other localities werefound in dark carbonaceous shale, but the other leaves from GraphitePeak were in cherty volcaniclastic Entisol paleosols (Morton pedotypeof Retallack and Krull, 1999). Glossopteris was the dominant genus ofdeciduous plant in low diversity high latitude wetlands of the Permian.Ages were assigned to the leaves based on their stratigraphic level inmeters by linear interpolation between end-Guadalupian and end-Per-mian carbon isotopic anomalies, at 15 and 256 m respectively at GraphitePeak, and 45 and 144.5 m on Portal Mountain (Retallack et al., 2005).

Chinese Taeniopteris leaves from the Shanxi and Shihhotse For-mations of Baode, in northwestern Shanxi, were measured for veindensity by Uhl and Mosbrugger (1999), and are Early to Middle Per-mian in age (Glaspool et al., 2002).

Methods— Vein density was measured with digital calipers asthe total length of veins within a area of one square centimeter, cut out

of a white cover card. At least 5 such measurements were made ondifferent parts of each leaf in order to obtain standard deviations andmeans in mm.mm-2. This method is more reliable and time consumingfor hand specimens than the measurement of intervein distance usedby Uhl and Mosbrugger (1999).

Results—Measurement of the vein density of glossopterid leaves(Fig. 5B) confirms visual impressions (Fig. 6) of pronounced increases

FIGURE 4. Permian gypsic and calcic paleosols from Oklahoma and Texas: (A)end-Permian deep clacic paleosols between shallow-calcic paleosols in the DeweyLake Formation, northern Caprock Canyons State Park, Briscoe Co., TX(N34.44955o W101.08271o); (B), end-Guadalupian deep-calcic paleosol betweenshallow calcic paleosols in the Yates Formation, 4 miles north Guthrie, King Co.,TX (N36.66738o W100.34130o); (C) carbonate nodules and calcareousrhizoconcretion from the Wellington Formation, 10 miles northwest of Tonkawa,Kay Co., OK (N36.741184o W97.425156o), (D), calcareous paleosol from theArcher City Formation 3 miles southwest of Archer City, Archer co., TX (N33.50165o

W99.95644o).

FIGURE 5. Time series of (A) atmospheric CO2 inferred from pedogenic-carbonate

carbon-isotope composition and from stomatal density of peltasperm pteridosperms;(B) sclerophylly of Antarctic Glossopteris and Chinese and Texan Taeniopteris;(C) inferred mean annual temperature from glendonites and paleosols in the northernSydney Basin, Australia: and (D) mean annual precipitation from paleosols in Texas-Oklahoma and South Africa. Data for A is from Retallack (2002a-b) and Royer etal. (2004); for B is from Uhl and Mosbrugger (1999) and Appendices 2-3, for C isfrom Carr et al., 1989, Loughnan (1991), Retallack (1999a-c) and Veevers et al.(1994), and for D is from Appendix 1, and supplementary information to Retallacket al. (2003). Error envelopes in gray are all one standard error.

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in vein density at the end-Guadalupian and end-Permian. There arealso large fluctuations in vein density of Texas Taeniopteris leaves,which are very sclerophyllous near the boundaries of the Asselian,Sakmarian, Artinskian, and Kungurian. Although the ChineseTaeniopteris were measured by a different method, so are not compa-rable in scale, these measurements do capture end-Artinskian and end-Kungurian increases in vein density (decrease in vein spacing).

There is no systematic bias of these results by oligotrophic car-bonaceous shaley matrix versus eutrophic volcaniclastic paleosols inthe Antractic glossopterid data, nor in levee versus lacustrine facies inthe Texas taeniopterids. One of the Antarctic Glossopteris (F36249)shows insect nibbling, but the other leaves appear healthy. Some of theTexas Taeniopteris leaves (localities 308908, 41884) appears flaccidand decayed by fungus or other microbes, but the others appear healthy.Nevertheless, because the high values of vein density are found at timesof warm-wet climate, they could be a response to soils predicted(Sheldon et al., 2002) and observed (Fig 5C) to be more deeply weath-ered of nutrient cations under such conditions. Such soils could also bea consequence of high atmospheric carbon dioxide and global green-house conditions (Retallack and Krull, 1999). Whatever the specificcause, these plants were episodically responding to environmental stress.

COMPARISON WITH CARBON DIOXIDE FROM LEAFSTOMATAL INDEX

My data on paleosol carbonate depth and leaf sclerophylly varia-tions through the Permian match well previously published estimatesof atmsopheric carbon dioxide from stomatal index studies (Fig. 5A).These data have previously been published (Retallack, 2002a-b), butare here recalculated using a new transfer function for carbon dioxidepartial pressure from stomatal index of living Ginkgo biloba (Wynn,2003). Peltasperm leaves indicate carbon dioxide levels near the nor-mal range (280-320 ppm historically) for the early Permian, but values

in excess of 2000 ppm for the end-Kungurian and end-Guadalupianand almost 8000 ppm for the end-Permian.

COMPARISON WITH CARBON DIOXIDE FROMPEDOGENIC CARBONATE

My data on paleosol carbonate depth and leaf sclerophylly alsoare not at variance with previously published estimates of atmosphericcarbon dioxide from the pedogenic carbonate isotopic paleobarometer(Fig. 5A). These data were previously published by Royer et al. (2004),who rejected anomalous results of Ekart et al. (1999). They have beenreadjusted here to the timescale of Gradstein et al. (2005) using strati-graphic levels listed by Tabor et al. (2002). The paleosol record ofcarbon dioxide has high temporal resolution, and potentially much higherresolution, than the stomatal index record, which relies on fossil leaveswith cuticular preservation (Retallack, 2002b). Some of the minor fluc-tuations in carbon dioxide indicated by the pedogenic paleobarometermatch fluctuations seen in vein density of Taeniopteris from these samedeposits (Fig. 5B). Also of interest is pedogenic confirmation of a risein carbon dioxide at the time of increased precipitation indicated bypaleosols at the Carboniferous-Permian boundary.

COMPARISON WITH TEMPERATURE FROM FRIGIDPALEOSOLS

The Sydney and Gunnedah Basins of southeastern Australia areprimarily marine, and include indications of frigid to cool temperateclimate from marine tillites and glendonites (Veevers et al., 1994).Named from Glendon Brook in the Hunter Valley, glendonites are ikaitepseudomorphs unstable in water temperatures above 5oC (Carr et al.,1989). Australian Permian and Carboniferous paleosols with variousforms of permafrost disruption have been taken as evidence of tundra(Retallack, 199c), taiga (Retallack, 1999b) and string bog ecosystems(Retallack, 1999a), in support of frigid to cool temperate paleoclimate.In contrast, other Permian stratigraphic horizons include kaolinitic andboehmitic paleosols and redeposited soils: especially in the Temi For-mation, upper Greta Coal Measures and correlative Koogah Forma-tion, near the Kulnura Marine Tongue of the Tomago Coal Measuresand correlative Dunedoo Formation, and in the lowest Dooralong Shaleand Garie Formation (Loughnan, 1991; Retallack, 1997a, 1999a; Boydand Leckie, 2000; Schofield and Jankowski, 2003). These paleosolsindicate chemical weathering of a degree and intensity found in Ultisols,which are currently found at latitudes no greater than 48o and in meanannual temperatures no lower than 12o C (Retallack and Krull, 1999).These various paleotemperature indicators are compiled in Figure 5C,using a time scale derived from linear regression of stratigraphic levelin the Hunter Valley (Veevers et al., 1994) versus radiometric dates,largely by SHRIMP U/Pb dating from zircons in tuffs (Gulson et al.,1990; Roberts et al., 1996; Facer and Foster, 2003). Once again, end-Carboniferous, end-Kungurian, end-Guadalupian and end-Permian tem-perature spikes stand well above otherwise cool conditions.

BIOSTRATIGRAPHY AND GREENHOUSE CRISES

Spikes in proxy paleoclimatic data from paleosols (Fig. 5C-D)and proxies for atmospheric carbon dioxide from fossil plants and soils(Fig. 5A) align at the end-Carboniferous, end-Cisuralian (end-Kungurian), end-Guadalupian, and end-Lopingian (end-Permian), whichdefine major divisions of the Permian (Fig. 7). These are also majormarine transgressions and sequence boundaries within marine rocks(Ross and Ross, 1995), presumbaly generated by transient greenhousepaleoclimates. These divisions are also apparent from evolutionarystages of marine conodonts (Mei and Henderson, 2001). The end-Guadalupian mass extinction among marine invertebrates was almostas large as the mass extinction at the end of the Permian, famous as thegreatest of all mass extinctions (Stanley and Yang, 1994).

On land in Texas and Oklahoma, edaphosaurid vertebrate fau-

FIGURE 6. Contrasting venation density in Permian glossopterid leaves fromGraphite Peak, Antarctica (S85.05138o E172.34948o), (A) Glossopteris decipiens(from 16.5 m in measured section of Retallack and Krull, 1999, intepreted as end-Guadalupian), and (B) Glossopteris browniana (from 106.5 m in measured sectioninterpreted as mid-Lopingian). These are specimens F36248 and F37110 respectivelyin the Condon Museum, University of Oregon.

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REFERENCES

nas and gigantopterid floras with many Carboniferous taxa persisteduntil Kungurian, after which floras changed dramatically from seedfern to conifer dominance (Dimichele et al., 2001, 2004). After theKungurian vertebrates were no longer preserved in Texas and Okla-homa (Lucas, 2004), which is a predicted consequence of observeddecalcified soils and sediments (Retallack, 1998). The end-Kungurianwas also a time when high-fiber, endosymbitoic, cellulytic herbivoresbecame dominant (Hotton et al., 1997), and sclerophyllous leaves be-came more prominent (Fig. 5B). Glossopterid vegetation of Antarctica,Australia and South Africa, also shows three distinct stages of evolu-tionary development (Anderson and Anderson, 1995; Retallack et al.,2005), as does the palynological zonation of Australia (Roberts et al.,1996). The end-Guadalupian extinction of the dinocephalian therapsidsin South Africa and Russia was a major extinction event, almost aslarge as the terminal-Permian extinction of therapsids at the end of theDicynodon zone (Rubidge, 1995; Benton et al., 2004), and not part of along-term slide toward mass extinction (contrary to Ward et al., 2005).Successive edaphosaurid, dinocephalian and dicynodont phases of tet-rapod evolution are apparent from both bone and footprint assemblages(Lucas, 2004).

Much attention has been focused on mechanisms of extinctionat the Permian-Triassic boundary, which is the greatest of the four Per-mian episodes of post-apocalyptic greenhouse recognized here. Atmo-spheric pollution with massive amounts of methane released from per-mafrost and submarine clathrates is indicated by global carbon isotopeexcursions (Krull and Retallack 2000, Retallack and Krull 2005), andevidence from fossil plants and soils of global warming during the ear-

FIGURE 7. Threefold Permian biostratigraphic divisions on land and at sea. Permian time scale is from Gradstein et al. (2005), conodont biostratigraphy from Mei andHenderson (2001), glossopterid zones from Retallack et al. (2005), palynological zones from Roberts et al. (1996), vertebrate stages from Lucas (2004), vertebrate zonesfrom Rubidge (1995), Hunter Valley stratrigraphy from Veevers et al. (1994) and Texas-Oklahoma stratigraphy from Lucas (2004).

liest Triassic (Retallack 1997b, 1999a, 2003). Such a large outburst ofmethane would create a greenhouse effect, which would linger as meth-ane was oxidized to carbon dioxide, consuming oxygen in the process.Modelling these effects combined with additions of carbon dioxide byextinctions and volcanic degassing, gives atmospheric oxygen contentas low as 12-15% by volume at the Permian-Triassic boundary, belowthe current 21%, and well below a modelled Permian-Carboniferousvalue of 35% (Berner, 2002, Berner et al., 2002). The consequences ofsuch a dysaerobic atmosphere would include hypercapnia and acidosisof marine invertebrates without active respiratory ventilation (Knoll etal., 1996), suffocation of roots of wetland plants already challenged foroxygen (Sheldon and Retallack, 2004), and pulmonary edema of verte-brates finding themselves in an atmosphere as sparsely oxygenated asat high altitudes today (Retallack et al., 2003). The trigger for theseabrupt greenhouses remains uncertain, and could be asteroid impact(Becker et al., 2004), flood basalt eruptions (Benton et al., 2004), ormassive submarine landslides (Krull et al., 2000). The Permian-Trias-sic boundary as the greatest extinction in the history of life is com-monly regarded as an exceptional case, but evidence presented here forother greenhouse crises of lesser magnitude suggests that global redoxand temperature are issues of vital concern to life on this planet.

ACKNOWLEDGMENTS

I thank Russell Hunt for help during with work and photos in thefield. Bill DiMichele helped with field advice, and both he and DanChaney generously allowed me to measure leaves in the collections ofthe US National Museum. Funded in part by NSF Grant OPP0230086.

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Location County Coordinates Formation Reference Eye-hght Level (m) T cm D cm S cm Age (Ma) Burial (km)

Caprock Canyons, TX Briscoe N34.45346 W101.08158 Dewey Lake F. Steiner 2001 47.7 82.3 17 53 2 248.69 0.168

Caprock Canyons, TX Briscoe N34.45346 W101.08158 Dewey Lake F. Steiner 2001 47.1 81.3 24 66 0.5 248.70 0.169




Caprock Canyons, TX Briscoe N34.45346 W101.08158 Dewey Lake F. Steiner 2001 38 66.3 18 99 1 248.89 0.184






1 mile E Dickens, TX Dickens N33.62552 W100.81791 Dewey Lake F. Steiner 2001 19.1 21.5 10 38 0.7 249.20 0.156


APPENDIX 1.

Pedogenic carbonate thickness (T), depth (D) and nodule diameter (S) measurements of Pennsylvanian, Permian and Triassic paleosolsfrom Texas and Oklahoma, USA

263












1 mile E Dickens, TX Dickens N33.62552 W100.81791 Dewey Lake F. Steiner 2001 12 9.8 12 35 1.1 249.27 0.168









1 mile E Dickens, TX Dickens N33.62552 W100.81791 Dewey Lake F. Steiner 2001 8.5 4.0 21 58 3 249.30 0.174








1 mile E Dickens, TX Dickens N33.62552 W100.81791 Dewey Lake F. Steiner 2001 5.9 -0.3 15 51 0.4 249.33 0.178



Caprock Canyons, TXB riscoe N34.45346 W101.08158 Dewey Lake F. Steiner 2001 16.4 30.7 18 66 0.6 249.35 0.220

















Caprock Canyons, TX Briscoe N34.45346 W101.08158 Dewey Lake F. Steiner 2001 13 25.1 25 56 0.8 249.42 0.226

















264

Caprock Canyons, TX Briscoe N34.45346 W101.08158 Dewey Lake F. Steiner 2001 6 13.5 10 32 0.2 250.37 0.237


























Caprock Canyons, TX Briscoe N34.44660 W101.07087 Alibates F. Steiner 2001 10 -29.7 15 42 0.7 252.69 0.280

Caprock Canyons, TX Briscoe N34.44660 W101.07087 Alibates F. Steiner 2001 9.5 -30.5 14 37 0.6 252.74 0.281

Caprock Canyons, TX Briscoe N34.44660 W101.07087 Alibates F. Steiner 2001 8.9 -31.5 13 36 2 252.79 0.282








4 miles N Guthrie, TX King N36.66738 W100.34130 Tansill F. Roth 1945 15.9 285.2 5 31 1 258.59 0.226








4 miles N Guthrie, TX King N36.66738 W100.34130 Tansill F. Roth 1945 5.3 267.7 9 38 0.8 258.86 0.244

4 miles N Guthrie, TX King N36.66738 W100.34130 Yates F. Roth 1945 4.6 266.6 10 42 0.6 258.87 0.245




4 miles N Guthrie, TX King N36.66738 W100.34130 Yates F. Roth 1945 2.1 262.4 25 72 3 258.94 0.249



13 mi.W Robert Lee, TX Coke N31.95408 W100.68438 Yates F. Mear 1961 5.3 335.9 27 38 4 259.92 0.237

12 mi.W Robert Lee, TX Coke N31.92433 W100.66223 Yates F. Mear 1961 11 335.3 16 41 2 259.93 0.237




13 mi.W Robert Lee, TX Coke N31.95408 W100.68438 Yates F. Mear 1961 4 333.8 26 35 2.5 259.93 0.239

13 mi.W Robert Lee, TX Coke N31.95408 W100.68438 Yates F. Mear 1961 3.1 332.3 21 44 1.1 259.94 0.240




13 mi.W Robert Lee, TX Coke N31.95408 W100.68438 Yates F. Mear 1961 1 328.8 24 49 3 259.96 0.244

12 mi.W Robert Lee, TX Coke N31.92433 W100.66223 Seven Rivers F Mear 1961 5.9 326.9 21 42 0.3 259.97 0.246


265

12 mi.W Robert Lee, TX Coke N31.92433 W100.66223 Seven Rivers F Mear 1961 4.3 324.2 17 34 0.4 259.99 0.249

12 mi.W Robert Lee, TX Coke N31.92433 W100.66223 Seven Rivers F Mear 1961 4 323.8 18 31 0.8 259.99 0.249

12 mi.W Robert Lee, TX Coke N31.92433 W100.66223 Seven Rivers F Mear 1961 1.4 319.5 15 26 4 260.02 0.253

12 mi.W Robert Lee, TX Coke N31.92433 W100.66223 Seven Rivers F Mear 1961 1.2 319.1 16 29 12 260.02 0.254

8 mi. E Guthrie, TX King N33.60949 W100.21466 Seven Rivers F Roth 1945 9.6 164.5 7 26 1.2 260.45 0.347

8 mi. E Guthrie, TX King N33.60949 W100.21466 Queen F. Roth 1945 5.5 157.8 5 22 0.8 260.55 0.354

8 mi. E Guthrie, TX King N33.60949 W100.21466 Queen F. Roth 1945 5 156.9 7 24 1 260.56 0.355

8 mi. E Guthrie, TX King N33.60949 W100.21466 Queen F. Roth 1945 4.1 155.5 5 23 0.9 260.59 0.356

8 mi. E Guthrie, TX King N33.60949 W100.21466 Queen F. Roth 1945 3.5 154.5 12 12 2 260.60 0.357

8 mi. E Guthrie, TX King N33.60949 W100.21466 Queen F. Roth 1945 2.9 153.5 10 18 3 260.62 0.358

Roman Nose S.P., OK Blaine N35.946327 W98.4212 Blaine F. Olson 1967 16 571.4 12 56 0.5 273.66 0.384

Roman Nose S.P., OK Blaine N35.946327 W98.4212 Blaine F. Olson 1967 13.5 567.3 10 52 0.5 273.82 0.388

Roman Nose S.P., OK Blaine N35.946327 W98.4212 Blaine F. Olson 1967 12.8 566.1 7 44 0.8 273.86 0.389

Roman Nose S.P., OK Blaine N35.946327 W98.4212 Blaine F. Olson 1967 7.8 557.9 30 56 5 274.19 0.397












5 mi SW Loyal, OK Blaine N35.95472 W98.2161 Flowerpot Sh. Olson, B. ‘62 1.8 497.0 44 71 0.5 276.57 0.458

5 mi SW Loyal, OK Blaine N35.95472 W98.2161 Flowerpot Sh. Olson, B. ‘62 1 495.7 20 63 1 276.62 0.459

5 mi SW Loyal, OK Blaine N35.95472 W98.2161 Flowerpot Sh. Olson, B. ‘62 0.5 494.9 15 54 1 276.65 0.460



4 mi. S Loyal, OK Blaine N35.91278 W98.15275 Flowerpot Sh. Olson, B. ‘62 2.6 462.0 34 56 4 277.94 0.493

4 mi. S Loyal, OK Blaine N35.91278 W98.15275 Flowerpot Sh. Olson, B. ‘62 1.8 460.7 10 44 0.6 277.99 0.494



0.1 mi.E North Blaine, OK Kingfisher N35.91612 W98.115585 Flowerpot Sh. Olson, B. ‘62 1 425.0 20 75 1 279.38 0.530

Copper Breaks S.P., TX Hardeman N34.10306 W99.74073 Choza F. Olson, B ‘53 22.6 1011.0 12 52 0.8 279.62 0.536

Copper Breaks S.P., TX Hardeman N34.10306 W99.74073 Choza F. Olson, B ‘53 22 1010.0 29 69 0.5 279.65 0.537


Copper Breaks S.P., TX Hardeman N34.10306 W99.74073 Choza F. Olson, B ‘53 19.5 1005.9 21 55 2 279.76 0.541

1.2 mi E North Blaine, OK Kingfisher N35.91338 W98.19138 Flowerpot Sh. Olson, B. ‘62 2.7 415.0 12 62 4 279.77 0.540

1.2 mi E North Blaine, OK Kingfisher N35.91338 W98.19138 Flowerpot Sh. Olson, B. ‘62 2 413.8 9 46 2 279.82 0.541



Copper Breaks S.P., TX Hardeman N34.10306 W99.74073 Choza F. Olson, B ‘53 17 1001.8 5 61 0.5 279.86 0.545

Copper Breaks S.P., TX Hardeman N34.10003 W99.74088 Choza F. Olson, B ‘53 16.8 1001.4 6 54 6 279.87 0.546


5.9 mi E Kingfisher, OK Kingfisher N35.911053 W97.83192 Hennessy Gr. Olson, B. ‘62 2 405.0 60 94 3 280.16 0.550

9.6 mi E Kingfisher, OK Kingfisher N35.912853 W97.78112 Hennessy Gr. Olson, B. ‘62 1.6 397.0 8 93 2 280.48 0.558

9.6 mi E Kingfisher, OK Kingfisher N35.912853 W97.78112 Hennessy Gr. Olson, B. ‘62 1 396.0 10 86 3 280.52 0.559

4.3 m. W Purcell, OK McClain N35.01717 W97.43943 Hennessy Gr. Olson 1967 1.8 391.0 25 67 3 280.71 0.564

4.3 m. W Purcell, OK McClain N35.01717 W97.43943 Hennessy Gr. Olson 1967 1.2 390.0 28 73 4 280.75 0.565

4.8 mi. N. Crowell, TX Foard N34.04613 W99.72506 Choza F. Nelson + ‘01 2.1 966.0 18 95 4 280.80 0.581

4.8 mi. N. Crowell, TX Foard N34.04613 W99.72506 Choza F. Nelson + ‘01 0.8 963.9 12 82 3 280.85 0.583

2 mi. N Crowell, TX Foard N34.00922 W99.72946 Choza F. Nelson + ‘01 1.6 956.0 15 48 1 281.06 0.591

Van Buren St, Purcell, OK McClain N35.022633 W97.36062 Hennessy Gr. Olson 1967 3.4 382.0 15 53 1 281.06 0.573

2 mi. N Crowell, TX Foard N34.00922 W99.72946 Choza F. Nelson + ‘01 1 955.0 44 93 1 281.08 0.592

Van Buren St, Purcell, OK McClain N35.022633 W97.36062 Hennessy Gr. Olson 1967 2.3 380.2 20 70 2 281.13 0.575

8 mi. SE Crowell, TX Foard N33.92368 W99.61153 Choza F. Nelson + ‘01 4 946.0 61 72 5 281.32 0.601

8 mi. SE Crowell, TX Foard N33.92368 W99.61153 Choza F. Nelson + ‘01 3.2 944.7 20 84 3 281.35 0.602




11 mi. N. Gilliland, TX Foard N33.82284 W99.595934 Choza F. Nelson + ‘01 9.7 930.0 65 80 0.8 281.74 0.617

11 mi. N. Gilliland, TX Foard N33.82284 W99.595934 Choza F. Nelson + ‘01 8.8 928.5 3 102 2 281.78 0.618


266



20.9 mi. NW Seymour, TX Foard N33.787716 W99.47923 Vale Formation Nelson + ‘01 7.8 900.0 22 69 1 282.52 0.647

20.9 mi. NW Seymour, TX Foard N33.787716 W99.47923 Vale Formation Nelson + ‘01 7 898.7 32 53 4 282.55 0.648






20.9 mi. NW Seymour, TX Foard N33.787716 W99.47923 Vale Formation Nelson + ‘01 2.8 891.8 31 58 0.8 282.74 0.655


20.9 mi. NW Seymour, TX Foard N33.787716 W99.47923 Vale Formation Nelson + ‘01 1 888.8 41 56 3 282.81 0.658

20.7 mi. MW Seymour, TX Foard N33.78355 W99.47675 Vale Formation Nelson + ‘01 2.2 882.0 15 59 1 282.99 0.665

20.7 mi. MW Seymour, TX Foard N33.78355 W99.47675 Vale Formation Nelson + ‘01 1.5 880.8 12 54 1.2 283.02 0.666

20.7 mi. MW Seymour, TX Foard N33.78355 W99.47675 Vale Formation Nelson + ‘01 1 880.0 26 59 0.6 283.04 0.667

2 mi NE Cashion, OK Noble N35.80915 W97.637276 Hennessey Gr. Olson 1967 0.8 330.0 12 72 3 283.10 0.625

2 mi NE Cashion, OK Noble N35.80915 W97.637276 Hennessey Gr. Olson 1967 0.4 329.3 10 62 2 283.12 0.626

19.7 mi. MW Seymour, TX Baylor N33.775414 W99.46578 Vale Formation Nelson + ‘01 1.8 868.0 38 86 1 283.36 0.679

19.7 mi. MW Seymour, TX Baylor N33.775414 W99.46578 Vale Formation Nelson + ‘01 1 866.7 46 82 1 283.39 0.680

17.0 mi. NW Seymour, TX Baylor N33.744125 W99.43857 Vale Formation Nelson + ‘01 4.5 864.0 25 57 0.4 283.46 0.683

17.0 mi. NW Seymour, TX Baylor N33.744125 W99.43857 Vale Formation Nelson + ‘01 4 863.2 36 62 0.4 283.48 0.684

17.0 mi. NW Seymour, TX Baylor N33.744125 W99.43857 Vale Formation Nelson + ‘01 3.6 862.5 43 73 3 283.50 0.684










13.1 mi. NW Seymour, TX Baylor N33.70331 W99.394394 Vale Formation Nelson + ‘01 1 812.0 24 63 4 284.82 0.735



11.0 mi. NW Seymour, TX Baylor N33.69.0037 W99.3635 Vale Formation Nelson + ‘01 1 784.0 52 63 3 285.55 0.763


10.5 mi. NW Seymour, TX Baylor N33.687454 W99.35486 Vale Formation Nelson + ‘01 2 770.0 66 81 3 285.91 0.777


1.5 mi.S Cimarron City, OK Logan N35.880154 W99.58691 Garber F. Olson 1967 5 252.0 15 54 6 286.15 0.703

8.9 mi. NW Seymour, TX Baylor N33.67928 W99.32992 Arroyo F. Nelson + ‘01 1 760.0 26 59 1 286.17 0.787

1.5 mi.S Cimarron City, OK Logan N35.880154 W99.58691 Garber F. Olson 1967 4.5 251.1 12 52 4 286.18 0.704

1.5 mi.S Cimarron City, OK Logan N35.880154 W99.58691 Garber F. Olson 1967 3.4 249.3 8 48 1 286.25 0.706

1.5 mi.S Cimarron City, OK Logan N35.880154 W99.58691 Garber F. Olson 1967 3 248.7 10 56 2 286.28 0.706

6.8 mi. NW Seymour, TX Baylor N33.666327 W99.29774 Arroyo F. Nelson + ‘01 5.3 750.0 45 78 10 286.44 0.797













9 mi SW Perry, OK Noble N36.20505 W96.36173 Garber F. Olson 1967 3 214.0 18 56 5 287.63 0.741

9 mi SW Perry, OK Noble N36.20505 W96.36173 Garber F. Olson 1967 2.5 213.2 34 73 3 287.66 0.742





9 mi SW Perry, OK Noble N36.20505 W96.36173 Garber F. Olson 1967 0.5 209.9 47 72 5 287.79 0.745



267




1 mi. NE Manitou, OK Tillman N34.522118 W98.99858 Garber F. Olson 1967 4 203.0 15 58 2 288.06 0.752

6 mi W Grandview, OK Tillman N34.249657 W98.80634 Garber F. Olson 1967 2 203.0 42 68 0.8 288.06 0.752

6 mi W Grandview, OK Tillman N34.249657 W98.80634 Garber F. Olson 1967 1.6 202.3 58 75 1 288.09 0.753

1 mi. NE Manitou, OK Tillman N34.522118 W98.99858 Garber F. Olson 1967 3.5 202.2 13 52 2 288.09 0.753







5 mi W Grandview, OK Tillman N34.237766 W98.77656 Garber F. Olson 1967 3 198.0 54 71 4 288.26 0.757




3.2 mi E Manitou, OK Tillman 34.507557 W98.92334 Garber F. Olson 1967 6.6 195.0 21 53 5 288.38 0.760


3.2 mi E Manitou, OK Tillman 34.507557 W98.92334 Garber F. Olson 1967 6 194.0 31 72 3 288.41 0.761


3.2 mi E Manitou, OK Tillman 34.507557 W98.92334 Garber F. Olson 1967 5 192.4 20 54 8 288.48 0.763








4.5 mi. E Manitou, OK Tillman N34.50754 W98.90229 Garber F. Olson 1967 3.5 184.0 22 57 10 288.81 0.771

4.5 mi. E Manitou, OK Tillman N34.50754 W98.90229 Garber F. Olson 1967 3 183.2 21 62 23 288.84 0.772

1.3 mi S Taylor, OK Cotton N34.154755 W98.33147 Garber F. Olson 1967 4.8 182.9 43 57 1 288.85 0.772


4.5 mi. E Manitou, OK Tillman N34.50754 W98.90229 Garber F. Olson 1967 2 181.5 12 54 6 288.90 0.773


1.3 mi S Taylor, OK Cotton N34.154755 W98.33147 Wellington F. Olson 1967 3 180.0 37 48 1 288.96 0.775

1.3 mi S Taylor, OK Cotton N34.154755 W98.33147 Wellington F. Olson 1967 2.3 178.8 45 56 1 289.01 0.776

1.5 mi. E Lake Kemp, TX Baylor N33.777756 W99.13785 Lueders Ls. Hentz 1988 5.5 648.0 38 83 5 289.10 0.899

1.5 mi. E Lake Kemp, TX Baylor N33.777756 W99.13785 Lueders Ls. Hentz 1988 5 647.2 39 82 3 289.12 0.900

1.3 mi S Taylor, OK Cotton N34.154755 W98.33147 Wellington F. Olson 1967 0.6 176.0 38 58 1 289.12 0.779

2 mi NE Orlando, OK Noble N36.16062 W97.34692 Wellington F. Olson 1967 1 175.0 43 62 4 289.16 0.780

2 mi NE Orlando, OK Noble N36.16062 W97.34692 Wellington F. Olson 1967 0.5 174.2 22 56 3 289.19 0.781

1.5 mi. E Lake Kemp, TX Baylor N33.777756 W99.13785 Waggoner R.F. Hentz 1988 2.3 642.7 31 81 12 289.24 0.904


2.5 mi. N Randlett, OK Cotton N34.208134 W98.45296 Wellington F. Olson 1967 4.8 172.0 49 72 1 289.27 0.783


2.5 mi. N Randlett, OK Cotton N34.208134 W98.45296 Wellington F. Olson 1967 3 169.0 48 71 1 289.39 0.786

1.5 mi. N Katie, OK Garvin N34.62735 W97.24773 Wellington F. Olson 1967 0.8 168.0 43 68 0.5 289.43 0.787




3.5 mi. N Katie, OK Garvin N34.651714 W97.25159 Wellington F. Olson 1967 1.2 158.0 50 62 4 289.82 0.797

3.5 mi. N Katie, OK Garvin N34.651714 W97.25159 Wellington F. Olson 1967 0.5 156.8 52 64 5 289.87 0.798

2 mi E Lake Kemp, TX Baylor N33.777008 W99.12762 Waggoner R.F. Hentz 1988 3.2 600.0 72 75 8 290.35 0.947

2 mi E Lake Kemp, TX Baylor N33.777008 W99.12762 Waggoner R.F. Hentz 1988 2.5 598.8 80 72 4 290.38 0.948

2 mi E Lake Kemp, TX Baylor N33.777008 W99.12762 Waggoner R.F. Hentz 1988 1 596.4 80 76 18 290.44 0.951

4 mi. E Lake Kemp, TX Baylor N33.788937 W99.07966 Waggoner R.F. Hentz 1988 5.7 561.0 53 66 10 291.37 0.986






4 mi. E Lake Kemp, TX Baylor N33.788937 W99.07966 Waggoner R.F. Hentz 1988 1 553.2 77 72 3 291.57 0.994

1 mi. SW Pauls Valley, OK Garvin N34.711838 W97.24889 Wellington F. Olson 1967 2.7 87.0 41 66 1 292.60 0.868


268




3 mi. W Kadane Corner, TX Archer N33.864395 W98.88989 Petrolia F. Hentz 1988 17.2 508.8 54 83 3 292.73 1.038

3 mi. W Kadane Corner, TX Archer N33.864395 W98.88989 Petrolia F. Hentz 1988 16 506.8 47 78 1 292.78 1.040

2 mi. SE Paoli, OK Garvin N34.80688 W97.24615 Wellington F. Olson 1967 8.2 81.0 43 62 3 292.83 0.874


5 mi. W Kadane Corner, TX Archer N33.829533 W98.93392 Petrolia F. Hentz 1988 4.4 502.0 60 80 0.4 292.91 1.045




5 mi. W Kadane Corner, TX Archer N33.829533 W98.93392 Petrolia F. Hentz 1988 3.6 500.7 43 61 0.5 292.94 1.046






2 mi. SE Paoli, OK Garvin N34.80688 W97.24615 Wellington F. Olson 1967 5 75.7 45 64 7 293.04 0.879














10 mi NW Tonkawa, OK Kay N36.741184 W97.42515 Wellington F. Olson 1967 2.4 69.0 5 52 5 293.30 0.886


10 mi NW Tonkawa, OK Kay N36.741184 W97.42515 Wellington F. Olson 1967 2 68.3 10 36 9 293.33 0.887




3 mi. S Rosedale, OK Garvin N34.835587 W97.19298 Oscar F. Olson 1967 2.8 62.7 39 56 1 293.55 0.892




1 mi.NW Kadane C’ner, TX Archer N33.874134 W98.84597 Petrolia F. Hentz 1988 1.2 440.0 42 64 0.4 294.53 1.107

1 mi.NW Kadane C’ner, TX Archer N33.874134 W98.84597 Petrolia F. Hentz 1988 0.1 438.2 34 66 0.3 294.57 1.109

3 mi. S Byars, OK McClain N34.85546 W97.10455 Oscar F. Olson 1967 6.8 24.7 42 49 2 295.03 0.930

0.2 mi.SE Kadane C’ner, TXArcher N33.85398 W98.836006 Petrolia F. Hentz 1988 1.8 420.0 42 66 2 295.05 1.127


0.2 mi.SE Kadane C’ner, TXArcher N33.85398 W98.836006 Petrolia F. Hentz 1988 0.8 418.4 46 84 0.2 295.09 1.129

0.2 mi.SE Kadane C’ner, TXArcher N33.85398 W98.836006 Petrolia F. Hentz 1988 0.6 418.0 44 73 1 295.10 1.129


3 mi. S Byars, OK McClain N34.85546 W97.10455 Oscar F. Olson 1967 5 21.7 48 51 6 295.15 0.933



3 mi. S Byars, OK McClain N34.85546 W97.10455 Oscar F. Olson 1967 3 18.4 42 53 4 295.28 0.937





3.5 mi. N Ringgold, TX Montague N33.8708 W97.946396 Nocona F. Hentz 1988 5 394.2 55 63 0.5 295.72 1.153

3.5 mi. N Ringgold, TX Montague N33.8708 W97.946396 Nocona F. Hentz 1988 4.5 393.4 61 67 0.4 295.74 1.154





3.5 mi. N Ringgold, TX Montague N33.8708 W97.946396 Nocona F. Hentz 1988 1.7 388.8 29 58 1 295.86 1.158


269


7 mi. W Nocona, TX Montague N33.810833 W97.90385 Nocona F. Jones, H’88 10 329.0 43 52 0.3 297.42 1.218

7 mi. W Nocona, TX Montague N33.810833 W97.90385 Nocona F. Jones, H’88 7 324.1 44 69 3 297.55 1.223

7 mi. W Nocona, TX Montague N33.810833 W97.90385 Nocona F. Jones, H’88 4.4 319.8 35 73 8 297.66 1.227



7 mi. W Nocona, TX Montague N33.810833 W97.90385 Nocona F. Jones, H’88 2.4 316.5 33 49 0.8 297.75 1.231



7 mi. W Nocona, TX Montague N33.810833 W97.90385 Nocona F. Jones, H’88 1 314.2 50 63 0.7 297.81 1.233


6 mi W Nocona, TX Montague N33.803364 W97.87049 Nocona F. Jones, H’88 5 309.8 73 64 3 297.93 1.237

6 mi W Nocona, TX Montague N33.803364 W97.87049 Nocona F. Jones, H’88 3.8 307.8 59 64 2 297.98 1.239




4 mi. W Nocona, TX Montague N33.78868 W97.79314 Archer City F. Jones, H’88 2.6 280.0 61 105 1 298.70 1.267

4 mi. W Nocona, TX Montague N33.78868 W97.79314 Archer City F. Jones, H’88 1.2 277.7 48 93 0.4 298.76 1.269

1 mi. E Archer City, TX Archer N33.59408 W98.59941 Archer City F. Hentz 1988 5.6 248.0 57 64 4 299.54 1.299



3 mi SE Archer City, TX Archer N33.540165 W96.95644 Archer City F. Hentz 1988 5.9 196.9 120 103 1 300.87 1.350

3 mi SE Archer City, TX Archer N33.540165 W96.95644 Archer City F. Hentz 1988 4.5 194.6 140 108 18 300.93 1.352

3 mi SE Archer City, TX Archer N33.540165 W96.95644 Archer City F. Hentz 1988 2 190.5 70 81 5 301.04 1.357

3 mi. W Markley, TX Young N33.545525 W98.49188 Markley F. Hentz 1988 10.3 144.9 88 92 0.8 302.23 1.402


USNM collection Locality name Formation Level m Age Ma Density mm.mm-2 s.d. (ls)41395 Buzzard Peak Blaine 1058 268.12 3.01 0.5240972 Cedar Top Clear Fork 898 274.54 2.63 0.4640987 Mixing Fork Clear Fork 895 274.66 2.49 0.44538908 Brushy Creek West Clear Fork 768 279.75 1.94 0.2240983 Head of Fish Creek Clear Fork 758 280.15 2.50 0.09341005 Colwell Creek Pond Clear Fork 738 280.96 2.75 0.2641884 Horseshoe Crab locality Leuders 645 284.69 2.05 0.2140049 Mitchell Creek Flats Waggoner Ranch 580 287.29 2.95 0.269321 Waggoner New Fence Waggoner Ranch 564 287.93 3.06 0.3540881 below Wattia locality Waggoner Ranch 562 288.01 2.96 0.4340020 Meteor Tank Petrolia 500 290.50 2.97 0.148960 Castle Hollow Petrolia 488 290.98 2.23 0.391961 Thaxton Ranch Nocona 382 295.23 2.10 0.46

APPENDIX 2

Vein density measurements of Texas Permian leaves of Taeniopteris.

OU specimen Locality name Formation Level m Age Ma Density mm.mm-2 s.d. (1s)F37108 Portal Mountain Weller 144 251.14 3.1 0.25F37102 Graphite Peak Buckley 252.2 251.15 2.02 0.08F35132A Mt Crean Weller 397 251.50 1.79 0.16F37109 Portal Mountain Weller 88 256.41 1.89 0.11F37101 Graphite Peak Buckley 113.5 256.56 2.3 0.22F35135 Graphite Peak Buckley 106.2 256.85 1.62 0.14F35148B Graphite Peak Buckley 106.2 256.85 1.82 0.04F36249 Graphite Peak Buckley 91 257.44 2.11 0.1F36250 Graphite Peak Buckley 75.5 258.046 2.19 0.41F36248 Graphite Peak Buckley 16.5 260.35 3.05 0.19F35130A Mt Crean Weller 170 260.40 2.82 0.22F37107 Portal Mountain Weller 45.3 260.42 2.43 0.12F37105 Portal Mountain Weller 41.6 260.77 1.97 0.08F37104 Portal Mountain Weller 38.8 261.03 2.08 0.09

APPENDIX 3

Vein density measurements of Antarctic Permian leaves of Glossopteris.

lucas, s.g. and zeigler, k.e., eds., 2005, the nonmarine...

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