Greenhouse crises of the past 300 million years

Gregory J. Retallack† Department of Geological Sciences, University of Oregon, Eugene, Oregon 97403, USA

ABSTRACT cate long-term high (>1000 ppmv) CO2 through None of these Quaternary fl uctuations greatly

much of the Mesozoic (Fig. 1). High temperature exceeds current levels of warmth and CO2, so

Proxies of past CO2 and climate over the and humidity in polar regions are thus viewed as predictions of future warming from those data

past 300 m.y. now reveal multiple global cli- long-term global CO2 greenhouse effects (Royer, represent a modest extrapolation. Fortunately, mate change events in unprecedented detail. 2006), and they are attributed to long-term con- the deeper geological record has many exam-

Evidence for past CO2 spikes comes from trols on the carbon cycle by tectonic uplift, ples of higher than modern CO2 levels from the expanded and refi ned stomatal index data oceanic gateways (Frakes et al., 1992), or plant- stomatal index of fossil plants (Retallack, 2001) of fossil Ginkgo and related leaves. New animal coevolution (Retallack, 2004). and warmth from degree of weathering of paleo- evidence for synchronous climatic change Exceptions to this long-lived Mesozoic green- sols (Retallack, 2007). comes from paleosols in Montana, Utah, and house, such as tillite in Early Cretaceous marine This paper provides new evidence for the link

neighboring states. Each CO2 spike was co- rocks of central Australia (David, 1907), were between atmospheric CO2 and climate in deep eval with unusually clayey, red, and decalci- regarded skeptically as evidence for Mesozoic time in four parts: (1) stomatal index evidence

fi ed paleosols that can be traced throughout periglacial paleoclimates until supported by the for atmospheric CO2, and (2) paleosol evidence the Colorado Plateau. Spikes in atmospheric discovery of glendonites, soil involutions, and for paleoclimate, before (3) statistical testing

CO2 also were coeval with increases in paleo- ice wedges in Australia (Alley and Frakes, 2003; of their correlation using superposed epoch sol alkali depletion as an indication of high Rich and Vickers-Rich, 2000). Other indications analysis (Prager and Hoenig, 1989), and, fi nally, temperature, and spikes in paleosol base of large spikes (7200 ppmv) in atmospheric CO2 (4) cross-correlation of the two time series to depletion and depth to calcic horizons as in- came from studies of the stomatal index of fossil derive power laws for changes in mean annual dications of high precipitation. In the Colo- plants (McElwain et al., 1999; Retallack, 2001, temperature and precipitation with increased rado Plateau, times of warmer climate were 2002) and paleosol carbon isotope composi- atmo spheric CO2. also more humid, perhaps due to the greater tion (Nordt et al., 2003; Prochnow et al., 2006; moisture potential of warmer air. Seasonal- Montañez et al., 2007). These short-term spikes REFINED GINKGO STOMATAL INDEX ity of climate did not increase during warm- are superposed on a modest (~500 ppmv CO2) PROXY FOR PAST CO2 wet spikes. The Mesozoic greenhouse was not Mesozoic greenhouse between Permian and persistently hot with cool spells, but warm Cenozoic icehouses (~300 ppmv CO2: Fig. 1). A paleobotanical gauge of atmospheric CO2 with hot fl ashes. These data furnish power The CO2 spikes at the end of the Middle and from stomatal index is based on observations laws predicting the sensitivity and magni- Late Permian correspond with indications from from greenhouse experiments and herbarium tude of change in mean annual tempera- paleosols of coeval increases in temperature, pre- specimens spanning postindustrial CO2 rise ture (MAT) and mean annual precipitation cipitation, and seasonality (Retallack et al., 2006; (Retallack, 2001). Plant leaves have fewer

(MAP) due to rising CO2 in a mid-latitude, Sheldon, 2006a). This paper both expands and stomates when atmospheric CO2 is high than

mid-continental region. The magnitude of refi nes the database for stomatal index records of when atmospheric CO2 is low (Wynn, 2003).

the coming anthropogenic greenhouse pales atmospheric CO2 and presents new data on paleo- Stomatal index is the number of stomatal open- in comparison with past greenhouse spikes at climatically sensitive features of paleosols in ings as a percent of epidermal cell plus sto- times of global mass extinctions. Utah, which record Mesozoic greenhouse paleo- mate numbers, and it is preferable compared to climate with unprecedented temporal resolution. measures of stomatal density because it is less INTRODUCTION New records presented here demonstrate that affected by competing effects of aridity, salin-

global warming due to CO2 rise is not a unique ity, and soil nutrient defi ciency (Beerling and Ever since Heer (1868) and Nathorst (1897) event in Earth history, and they offer the pros- Royer, 2002). Stomatal index may also respond

reported fossil ferns, cycads, and dicots of pect of refi ning predictive models of climate to volcanogenic SO2, but an SO2 effect cannot

Malay sian affi nities in Jurassic and Cretaceous response to CO2 forcing. Climate effects of yet be disentangled from that of more abun-

rocks of Spitsbergen and Greenland, cosmo- anthropogenic CO2 production have been pre- dant volcanogenic CO2 (Tanner et al., 2007).

politan Mesozoic fossil fl oras have been taken dicted from the single, incomplete natural ex- Stomatal response to atmospheric CO2 is taxon as evidence that Mesozoic paleoclimates were periment represented by “hockey-stick” graphs specifi c, so attention has focused on Ginkgo,

warm and humid (Vakhrameev, 1991) and of recent temperature and CO2 rise above natural which has an exceptionally long fossil record. lacking in large glaciers even at high latitudes variation of past centuries (Alley et al., 2007). A Ginkgo biloba is very similar morphologically (Frakes et al., 1992). This view is refl ected also more representative sample of eight completed and paleoecologically to Ginkgo adiantoides in computer models (Berner, 2006), which indi- global experiments of the past comes from back to the Late Cretaceous (Royer et al., 2003). glacial-interglacial variation in ice-core proxies The genus Ginkgo, defi ned on the basis of both † E-mail: [email protected]. for CO2 and temperature (Augustin et al., 2004). morphology and cuticular structure, goes back

GSA Bulletin; September/October 2009; v. 121; no. 9/10; p. 1441–1455; doi: 10.1130/B26341.1; 10 fi gures; 2 tables; Data Repository item 2009025.

For permission to copy, contact [email protected] 1441 © 2009 Geological Society of America Retallack

PALEO. MESOZOIC CENOZOIC Permian Triassic Jurassic Cretaceous Tertiary Q. 8000 Ginkgo stomatal index

6000

(ppmv) 2 GEOCARBSULF 4000

2000

Atmospheric CO Atmospheric 0 300 250 200 150 100 50 0 Age (Ma)

Figure 1. Alternative atmospheric CO2 time series from mass balance model of carbon

burial (gray—GEOCARBSULF of Berner, m

2006) and stomatal index of Ginkgo and μ Lepidopteris (black—Retallack, 2001, 2002; A 1 cm 100 μm see also GSA Data Repository [see text foot- BC 100 note 1]). to the Triassic (Anderson and Anderson, 1989), where the oldest Ginkgo leaves in this compila- tion have the same cuticular structure and sto- matal index as Lepidopteris leaves in the same deposits. Lepidopteris stomatal indices in this D 1 cm compilation are no younger than latest Jurassic, when the genus became extinct. Lepidopteris and allied plants have been used to extend the paleobotanical CO2 paleobarometer back into the Permian (Retallack, 2001, 2002).

New Data EF1 cm 100 μm G μ Fossil cuticles are widely used in taxonomic 100 m studies of fossil plants, and additional relevant accounts of fossil plants have been published Figure 2. Jurassic and Cretaceous leaves from Montana, and their cuticles: (A–C) “Ginkgoites” since recent compilations of stomatal index cascadensis from the Late Jurassic (Tithonian, 150 Ma) upper Morrison Formation near data (Retallack, 2001, 2002). Also, new data Belt, Montana. (D–G) Ginkgo pluripartita from the Early Cretaceous (Aptian, 125 Ma) from museum specimens and preparations have Kootenai Formation near Great Falls. Photomicrographs B and F are upper cuticles been added, especially Jurassic and Creta ceous lacking stomates, and C and G are lower cuticle with stomatal apertures overhung by leaves from Montana, USA (Fig. 2), Creta- dark papillae. ceous leaves from Victoria (Australia), and Permian leaves from Russia (Retallack et al., 2006). The number of stomatal index records herbarium specimens spanning the postindus- The standard error of this relationship (±37 ppmv) meeting leaf number (5) and cell number (500) trial rise of CO2, with addition of published is trivial compared with standard deviation of rarefaction criteria for quality now stands at 146, greenhouse experimental results (Beerling individual stomatal index measurements (aver- 20 of which are new, and 18 of which have been et al., 1998). That original curve-fi t, and others, aging ±0.9% and resulting in an average error adjusted for refi nements in geological age dat- were reassessed by Wynn (2003), who proposed +2947/–473 ppmv for all 146 determinations). ing (see GSA Data Repository1). a new transfer function, which was modeled on fundamental equations of Fickian diffusion but Limitations and Comparisons of the

New Transfer Function which still was based on herbarium and green- Ginkgo CO2 Proxy house data used by Retallack (2001). Additional

The transfer function used by Retallack herbarium and greenhouse data published by The highest calculated levels of CO2, a stag-

(2001) to infer atmospheric CO2 from Ginkgo Beerling and Royer (2002) now call for minor gering 7200 ± 3000 ppmv at the end-Permian stomatal index was based on measurements of revision of the transfer function (Fig. 3). Esti- mass extinction, are now confi rmed by replicate

mation of atmospheric CO2 (O in ppmv) from data from fossil leaves of Russia, India, and stomatal index (I in %) is now based on the fol- Australia (Retallack et al., 2006). For compari- 1 GSA Data Repository item 2009025, Stomatal lowing formula: son, postglacial-preindustrial CO levels were index and paleosol data, is available at http:// 2 www.geosociety.org/pubs/ft2009.htm or by request no more than 280 ppmv, 2007 levels topped out to [email protected]. O = 294.1 + [1/(4.84 × 10–10) × I7.93]. (1) at 386 ppmv, and levels of 856 +70/–101 ppmv

1442 Geological Society of America Bulletin, September/October 2009 Past greenhouse crises

16 appointing because of different time scales and PALEOSOL RECORD OF 15 14 dating methods used in their construction. Plot- PALEOCLIMATE 13 ting all isotopic results from a formation against 12 x = 294.1 + (1/((4.84.10–10).y7.93) a single geological age (Veizer et al., 2000), As a record of past CO2 greenhouse paleo- 11 and using moving averages to subdue outliers climates, the Ginkgo record is only half the 10 (Montañez et al., 2007), does not allow recogni- story. Proxies for paleoclimate are also needed, stomatal index (%) index stomatal 9 8 tion of spikes critical to this study. The result- preferably with high temporal resolution. 7

Ginkgo Wynn (2003) ing pedogenic calcite estimates are subdued in Paleosols are suitably abundant proxies for 6 200 300 400 500 600 700 800 900 1000 direct graphic comparisons with stomatal index paleocli mate, from both their carbonate profi le

Atmospheric CO2 (ppmv) spikes (such as Figure 5 of Retallack, 2005b). morphology (Retallack, 2005a) and chemical Isotopic records from the same paleosols used composition (Sheldon et al., 2002). Only cal- Figure 3. New transfer function (black) for to indicate paleoclimate here would obviate the careous paleosols (pedocals of Marbut, 1935) inferring atmospheric CO2 (ppmv) from need for precise correlation and dramatically were used in this study because fi eld observa- stomatal index of Ginkgo biloba leaves, ap- improve temporal resolution (Figs. 4–5): such tions of carbonate nodules could be compiled plying formulation of Wynn (2003, in gray) isotopic analyses are in progress and will take rapidly to obtain an overview of paleo climatic to herbarium and greenhouse data used by time to complete. Two other problems for the changes with high temporal resolution. Retallack (2001) as well as subsequent data pedogenic carbonate CO2 paleobarometer are Pedocals are found only within semiarid to of Beerling and Royer (2002). also under ongoing study (rendering it currently sub humid climatic belts (300–1000 mm mean less precise than stomatal indices): (1) determin- annual precipitation) and so record climatic ing representative organic matter carbon isotopic variation within those limits (Retallack, 2005a). are expected by the year 2100 in the A2 emis- values from decayed organic matter of paleosols This study was also geographically limited to sion scenario of a heterogeneous world with (Wynn, 2007); and (2) estimating former soil southwestern Montana for most of the Cenozoic continued population growth (Alley et al., respiration levels (Montañez et al., 2007). There (0–45 Ma: Retallack, 2007), and Utah and

2007). Equation 1 cannot discern CO2 levels is also a problem with the use of oxygen isotope nearby states for the earlier (43–300 Ma) record less than 294 ppmv, because Ginkgo leaves values as paleotemperature indicators during back to the Permian (Fig. 4). The Eocene over- from Quaternary glacial stages or comparable carbonate formation of long-term drift, because lap of Utah and Montana records is seamless be- experiments were not in its training set and re- they give unrealistically high paleotemperatures cause these regions are not only geographically main unknown. in deep time, as noted by Veizer et al. (2000). close, but they were paleogeographically similar Variance of stomatal index measurements is These problems are potentially soluble, and iso- during the Eocene (Goldstrand et al., 1993). The

minimized by two rarefaction criteria: at least topic studies of paleoclimate and CO2 provide subsequent geological history of Utah and Mon- 500 cells counted (Retallack, 2001) and at least great promise for the future. tana intermontane basins has also been similar

fi ve separate leaves counted (Royer et al., 2004). Other proxies for former atmospheric CO2 (Hintze, 1988; Retallack, 2007). Nevertheless, standard deviation of individual include mass balance models of sedimentary stomatal index measurements remains so large carbon and sulfur (Berner, 2006), and strontium New Data

that atmospheric CO2 estimates are imprecise, isotopic values of marine carbonates (Roth- and this is exacerbated by extrapolation to val- man, 2002), but these marine records calculated This paper reports 2468 new paleosols, added ues beyond the data range of the transfer func- in steps of 10 m.y. present a necessarily sub- here to 1250 previously documented paleosols tion (Fig. 3). Another limitation of the Ginkgo dued record of global change compared with (Retallack, 2005a, 2007). Locations for study of record of past atmospheric CO2 is temporal pedogenic carbonate and stomatal index data paleosols were chosen at the exact sections used incompleteness. Added data have served to ac- (Fig. 1). Marine algal carbon isotope composi- for previously published magnetostratigraphic centuate and confi rm the rapidity of some of tion (Kaufman and Xiao, 2003; Pagani, 2002) and radiometric dating, so that ages of paleo- the CO2 spikes, but other spikes remain poorly and base depletion of paleosols (Sheldon, 2006b) sols in those sections could be interpolated be- constrained, and long stretches of time have not have low precision, but they have been usefully tween specifi c dated stratigraphic levels (Fig. 5; yet yielded fossil leaves of suitable preserva- applied to unusually high levels of Precambrian Table 1). Standard errors of linear regression of

tion. This is unlikely to change signifi cantly in CO2. Alkenone organic carbon data compared age against stratigraphic level are all compara- the future because recent progress has refi ned with foraminiferal carbonate carbon isotopes ble with radiometric dating errors (<2 m.y.), but our understanding of known fossils rather than (Pagani, 2002), and foraminiferal boron iso- were not calculated for interpolations based on discovering new fossils. topes (Pearson and Palmer, 1999) have been ap- only two tie points (Table 1). No new geochrono- Paleosol carbonate carbon isotopic compo- plied to Cenozoic records only, because they are logical data are presented here, although paleo- sition (δ13C) is another proxy for atmospheric vulnerable to organic thermal maturation and car- magnetic chrons were assigned geological ages

CO2, comparable with the Ginkgo record, that bonate diagenesis. The alkenone proxy is limited using a more recent time scale (Gradstein et al.,

indicates short-term dramatic changes during to CO2 levels lower than 1250 ppmv, and boron 2004) than that available when local chrons the Permian, Triassic, and Cretaceous (Nordt isotopes may be compromised by variations were originally determined. Dating during the et al., 2003; Prochnow et al., 2006; Montañez in river input to the ocean (Royer et al., 2001). Early Permian (Kiaman: 299–265 Ma) reversed et al., 2007). Highly volatile variation in δ18O Goethite-occluded carbonate in paleosols (Tabor superchron is based on sequence stratigraphic values from well-preserved fossil marine shells and Yapp, 2005) is rarely preserved because of correlation with Texas (Baars, 1987; Huntoon (Veizer et al., 2000) is also supportive of rapid burial dehydration of goethite to hematite (Retal- et al., 2002; Scott, 2005), which in turn was climate change over the past 300 m.y. Direct lack, 1991), but those paleosols analyzed show dated by U-Pb radiometry and ammonoid bio- correlation of oxygen isotope and stomatal in- excellent agreement with pedogenic carbonate stratigraphy (Rasbury et al., 1998; Retallack, dex time series by Retallack (2002) proved dis- and stomatal index estimates of past CO2. 2005b). The Cretaceous normal superchron

Geological Society of America Bulletin, September/October 2009 1443 Retallack

Paleosol carbonate nodules Size ProfileDepth Age (Ma) Rock Units Composite section Locality list Map of localities A B CD E Km F G H 50 Uinta Formation 6 40. Bonanza Eo. 39. Kyune, IDAHO Colton Formation WYOMING Pal. Flagstaff Limestone 38. Axhandle Canyon 37. Black Dragon Creek Pocotello North Horn Formation 36. North Horn Mountain 24 Kaiparowits (35. Wales Canyon) Formation 5 (34. Wales) UTAH Laramie 100 33. The Blues Straight Cliffs 32. Cedar Canyon Salt Lake City 6 Formation 31. Henrieville 22 40°N 40

Cretaceous Denver Dakota Formation (30. Valley of Fire) 1639 (29. Salina) Cedar Mountain 35 Price 28. Little Cedar Mountain 34 Formation 4 38 36 28 19 21 COLORADO 27. Moab 26 37 18 8 7 25 5 Morrison Formation (26 Christianburg) NEVADA 29 2712 150 Summerville 25. Dalton Wells 20 24. Como Bluff 33 9 Formation 32 31 3 23. Montezuma Creek 17 Carmel Formation 131014 1 2 23 22. Dinosaur 11 15 Temple Cap 3

Jurassic 21. Fruita 30 Santa Fe 4 Formation 20. Notom Las Vegas Navajo Sandstone 19. Cisco Albuquerque 18. South Salt Wash 200 Kayenta Formation Flagstaff 17. Cannonville 35°N 200 km Wingate Sandstone (16. Thistle) 2 ARIZONA NEW MEXICO Moenave Formation 15. Paria 14. La Verkin Hill 115°W 110°W 105°W Chinle Group climbing translatant bedding Triassic 13. Gunlock Cameron Formation trough cross-bedding 12. Kane Springs Canyon planar bedding Shinarump Sandstone 11. Kanab 250 conglomerate Moenkopi Formation 10. Ivins fossil plants fossil bones 1 9. Hog Springs sandstone Bernal Formation marine fossils White Rim Sandstone 8. Crawford Draw 7. Upheaval Dome claystone red-orange Organ Rock Shale (6. Parleys Canyon) Permian coal yellow-gray Cedar Mesa Formation 5. Salt Creek Canyon map 4. Bernal area Halgaito Shale 0 limestone gray-green coalclaysilt sand gravel 3. Hite cm 50100 50 100 100 200 cm 2. Snake Canyon (Localities in parentheses are from laterally equivalent 1. Moki Dugway formations other than those listed)

Figure 4. Sites and stratigraphic setting of paleosols examined. (A–C) Raw fi eld measures (cm), uncorrected for burial compaction, of calcareous paleosol nodule diameter (A), depth to nodular horizon (B), and thickness of paleosol with nodules (C), which are input param- eters for calculating paleoprecipitation and time for formation of the paleosols. (D) Geological time scale (after Gradstein et al., 2004). (E–F) Composite section of geological formations examined (km). Lines between formations show short time spans of eolian and fl uvial sandstones compared with paleosol-rich red beds. (G–H) Paleosol sites examined in Utah and neighboring states and their stratigraphic distribution (sites in parentheses are from laterally equivalent formations other than those shown).

(125–84 Ma) was fortunately a time of volcanic position and thickness of separating sediments gressions between age and stratigraphic level and tectonic activity producing radiometrically within local sections, and that signifi cant dis- (Fig. 5), yet the regressions explain most of the datable tuffs and transgressions of ammonite- conformities have been recognized by past variance (R2 > 0.9), thus validating assumptions. bearing marine sediments in Utah and Nevada sequence-stratigraphic research. For example, Stratigraphic level was measured by the (Carpenter and Carpenter, 1987; Goldstrand separate age models were used for the mem- method of eye-heights, and observed carbon- et al., 1993). bers of the Morrison and Cedar Mountain For- ate nodular horizons were measured with a Two key components of this work were mations at Little Cedar Mountain, Cisco, and milliner’s tape. Samples of paleosol clayey B (1) measuring the stratigraphic level of each Moab (Kirkland et al., 1999), and missing sec- horizons were also collected for major-element paleosol at the same sites as prior geochrono- tions fi lled with paleosols of intervening age analysis using X-ray fl uorescence (XRF) by logical studies, and (2) creating site-specifi c age elsewhere, for example, at Como Bluff (Bakker , ALS Chemex of Vancouver British Columbia models for unconformity-bounded sequences. 1998) and Salina (Sprinkel et al., 1999). Large against Canadian granodioritic stream sand stan- This procedure assumes that the relative age variations in sediment accumulation rate or dard STSD-2. Both carbonate measurements of paleosols is refl ected in their order of super- disconformities would produce outliers to re- and chemical proxies of paleosols were ordered

1444 Geological Society of America Bulletin, September/October 2009 Past greenhouse crises

A. Bonanza, UT B. The Blues, UT C. Salt Wash, UT 47 76 161.5

46 75.5 45 161

44 75

43 Age (Ma) 160.5

Age (Ma) Age (Ma) y = –0.011x + 48.49 74.5 y = –0.0024x + 76.16 y = –0.0288x + 162.34 42 R 2 = 0.99 R 2 = 0.99 R 2 = 0.97 SE = 0.26 Ma SE = 0.08 Ma SE = 0.08 Ma 41 74 160 0 200 400 600 800 0 200 400 600 800 1000 20 30 40 50 60 70 Stratigraphic level (m) Stratigraphic level (m) Stratigraphic level (m)

D. Gunlock, UT E. Kane Springs Canyon, UT F. Crawford Draw, UT 180 182 218

178 181 216 176 180 174 214 y = –0.0071x + 179.04 y = –0.0172x + 181.52 Age (Ma) y = –0.0749x + 219.02

Age (Ma) 179 Age (Ma) 172 R 2 = 0.97 R 2 = 0.99 R 2 = 0.97 SE = 0.47 Ma SE = 0.11 Ma SE = 0.34 Ma 170 178 212 0 200 400 600 800 1000 0 50 100 150 0 20 40 60 80 100 Stratigraphic level (m) Stratigraphic level (m) Stratigraphic level (m)

Figure 5. Examples of geological dating of paleosols by site-specifi c linear interpolation of radiometric or paleomagnetic ages (see GSA Data Repository for details of all site chronologies [see text footnote 1]).

by numerical age (Ma) rather than stratigraphic measures are related to mean annual precipita- climate (Jenny, 1941). They refl ect increases in level because of the great variation in depo- tion (MAP in mm; with R2 = 0.52, SE ±147 mm fundamental weathering reactions (hydrolysis sitional rate in time and space throughout the for D, and R2 = 0.72, SE ±182 mm for C), mean or enrichment of alumina over alkali earths and Colorado Plateau (Fig. 4). Full details of locali- annual range of precipitation (MARP, differ- soda) with increased precipitation, and deple- ties, their age constraints, and paleosol carbonate ence between wettest and driest monthly mean, tion of alkalis (soda and potash) with increased measurements and chemical analyses are in the in mm; with R2 = 0.58, SE ±22 mm), mean an- temperature. Both geochemical ratios reveal GSA Data Repository (see footnote 1). nual temperature (MAT in °C; with R2 = 0.37, promotion of base depletion by temperature and SE ±4.4 °C), and duration of formation of paleo- precipitation: bases are in the numerator of one Transfer Functions Used sols (A in k.y.; with R2 = 0.57, SE ±1.8 k.y.), versus denominator of the other ratio, but they by the following equations derived from large are used in negative versus positive transfer func- Three variables were measured in the fi eld databases for modern soils (Sheldon et al., 2002; tions. The training set of modern soils used for for each paleosol (Fig. 6): depth to Bk horizon Retallack, 2005a): these transfer functions spans a range of 2–20 °C (D in cm), thickness of paleosol with nodules MAT and 200–1600 mm MAP, which is suit- (T in cm), and maximum size of carbonate nod- MAP = 137.24 + 6.45D – 0.013D2, (2) able for mildly calcareous paleosols of Utah and ules (N in cm). Standard deviations of replicate Montana but is not designed for extreme base measurements on single paleosols are < 1 cm. MAP = 221e0.0197C, (3) depletions of Oxisols or bauxite soils (Sheldon In addition, selected clayey (Bt) horizons were et al., 2002). The distribution of carbonate nod- sampled and analyzed by XRF to determine MARP = 0.79T + 13.71, (4) ules in modern soils refl ects soil respiration lev- chemical index of alteration without potash els as a source of CO2 and carbonic acid, and

(C = 100·mAl2O3/[mAl2O3 + mCaO + mNa2O], MAT = –18.5S +17.3, (5) these in turn are related to primary productivity where m is moles) and alkali index (S = of vegetation and mean annual precipitation. 0.34 [mK2O + mNa2O]/mAl2O3, where m is moles). A = 3.92N . (6) High soil respiration of woodlands limits carbon- Two standard deviations of these determina- ate nodules to deep horizons within soil profi les, tions are ±0.23 wt% for alumina, and less for These various climofunctions are empirical: compared with low-soil-respiration levels of other elements (see Data Repository [see foot- based on compilations of data from modern soils desert shrublands. In highly seasonal monsoonal note 1]). These various fi eld and chemical controlled for soil-forming factors other than climates, soil respiration levels vary greatly with

Geological Society of America Bulletin, September/October 2009 1445 Retallack

TABLE 1. AGE MODELS USED FOR ALL EXAMINED PALEOSOL LOCALITIES Location Age abR2 SE n Selected references Axhandle Canyon, Utah Paleocene-Eocene –0.0362 64.38 0.99 0.35 14 Retallack (2005a) Bernal, New Mexico Late Permian –0.6750 284.34 – – 2 Muehlberger et al. (1960) Bernal, New Mexico Early Triassic –0.0227 243.84 – – 2 Molina-Garza et al. (1996) Black Dragon Creek, Utah Paleocene –0.0450 60.93 – – 2 Tomida and Butler (1980) Black Dragon Creek, Utah Paleocene –0.1186 65.35 0.96 0.45 5 Tomida and Butler (1980) Bonanza, Utah Eocene –0.0110 48.49 0.99 0.26 4 Prothero (1996) Cannonville, Utah Middle Jurassic –0.0460 167.28 – – 2 Kowallis et al. (2001) Castle Dale, Utah Early Cretaceous –0.4238 146.32 – – 2 Kirkland et al. (1999) Cedar Canyon, Utah Late Cretaceous –0.0153 91.09 – – 2 Eaton et al. (1999) Christianburg, Utah Early Cretaceous –0.0804 125.67 0.99 0.52 3 Sprinkel et al. (1999) Cisco, Utah Late Jurassic –0.0374 155.13 – – 2 Turner and Peterson (1999) Cisco, Utah Early Cretaceous –0.5429 136.40 – – 2 Kirkland et al. (1998) Como Bluff, Wyoming Late Jurassic –0.1610 157.24 – – 2 Bakker (1998) Crawford Draw, Utah Late Triassic –0.0749 219.02 0.97 0.34 6 Reeve (1975) Dalton Wells, Utah Early Cretaceous –1.3938 144.46 0.94 3.56 3 Kirkland et al. (1999) Dinosaur-Fruita, Colorado Late Jurassic –0.0393 154.70 0.94 0.71 9 Turner and Peterson (1999) Gunlock, Utah Late Cretaceous –0.0218 82.45 – – 2 Fillmore (1989) Gunlock, Utah Middle Jurassic –0.0109 169.08 0.83 0.55 5 Kowallis et al. (2001) Gunlock, Utah Middle Jurassic –0.1852 174.15 – – 2 Kowallis et al. (2001) Gunlock, Utah Early Jurassic –0.0071 179.04 0.97 0.47 8 Johnson (1976) Hite, Utah Early Triassic –0.0374 354.9 – – 2 Reeve (1975), Baars (1987) Hog Springs, Utah Early Jurassic –0.2381 198.74 0.82 0.21 3 Reeve (1975) Honaker Trail, Utah Pennsylvanian –0.0476 323.09 0.93 1.27 3 Scott (2005) Ivins, Utah Late Triassic –0.2414 204.64 – – 2 Lucas and Tanner (2007) Kanab, Utah Early Jurassic –0.2105 194.03 – – 2 Ekstrand and Butler (1989) Kane Springs Canyon, Utah Early Jurassic –0.0172 181.52 0.99 0.11 5 Steiner and Helsley (1974) Kane Springs Canyon, Utah Middle Triassic –0.0946 237.46 – – 2 Lucas et al. (1997) Kane Springs Canyon, Utah Early Triassic –0.0465 250.79 – – 2 Blakey et al. (1993) Kyune, Utah Eocene –0.0362 64.38 0.99 0.35 14 Zawiskie et al. (1982) La Verkin Hill, Utah Middle Jurassic –0.0050 169.95 – – 2 Kowallis et al. (2001) Little Cedar Mountain, Utah Mid-Cretaceous –0.2105 132.71 0.87 4.71 3 Kirkland et al. (1999) Little Cedar Mountain, Utah Early Cretaceous –0.4238 146.32 – – 2 Kirkland et al. (1999) Little Cedar Mountain, Utah Late Jurassic –0.0222 149.02 – – 2 Turner and Peterson (1999) Moab, Utah Mid-Cretaceous –0.1497 125.82 0.67 2.07 4 Kirkland et al. (1999) Moab, Utah Early Cretaceous –3.6364 372.2 – – 2 Kirkland et al. (1999) Moab, Utah Late Jurassic –0.0176 151.73 – – 2 Turner and Peterson (1999) Moki Dugway, Utah Early Permian –0.0842 261.28 – – 2 Scott (2005) Montezuma Creek, Utah Late Jurassic –0.0385 146.23 0.72 0.66 4 Kowallis et al. (1991, 1998) North Horn Mountain, Utah Late Cretaceous –0.0250 70.60 – – 2 Difley and Ekdale (1999) Notom, Utah Mid-Cretaceous –0.6040 211.76 – – 2 Kowallis and Heaton (1987) Notom, Utah Early Cretaceous –0.3239 185.14 – – 2 Kirkland et al (1999) Notom, Utah Late Jurassic –0.0370 154.87 – – 2 Kowallis et al. (1998) Paria, Utah Middle Jurassic –0.1135 166.20 – – 2 Evans (1996); Caputo (2003) Parleys Canyon, Utah Middle-Early Triassic –0.0435 247.30 0.99 0.05 3 Croes (1978) Parleys Canyon, Utah Late Triassic –0.1138 218.25 0.84 1.62 10 Croes (1978) Salina, Utah Early Cretaceous –0.0494 114.38 – – 2 Sprinkel et al. (1999) Salt Creek Canyon, Colorado Early Triassic –0.0322 247.62 0.91 0.56 11 Helsleyand Steiner (1974) Snake Canyon, Utah Middle Permian –0.0766 291.80 – – 2 Huntoon et al. (2002) South Salt Wash, Utah Middle Jurassic –0.0288 162.34 0.96 0.08 8 Steiner (1978) The Blues, Utah Late Cretaceous –0.0024 76.16 0.99 0.08 4 Roberts et al. (2005) Thistle, Utah Middle Jurassic –0.0143 167.94 – – 2 Kowallis et al. (2001) Upheaval Dome, Utah Middle Triassic –0.1843 229.36 – – 2 Lucas et al. (1997) Valley of Fire, Nevada Early Cretaceous –0.0232 97.33 – – 2 Carpenter and Carpenter (1987) Wales Canyon, Utah Paleocene –0.0152 74.45 0.99 0.47 4 Talling et al. (1994) Wales Canyon, Utah Late Cretaceous –0.0255 77.33 0.99 0.11 4 Talling et al. (1994) Wales, Utah Early Cretaceous –0.0863 104.00 – – 2 Sprinkel et al. (1999) Note: All age models are based on two or more (n) tie points by linear regression of the form y = ax + b, where y is age (Ma), x is stratigraphic level (m), a is slope of regression, b is intercept of regression, R 2 is least squares coefficient of determination, and SE is standard error of y on x (not calculated for two-point regressions). Example regressions are shown in Figure 5. Full references, stratigraphic level, and age pick for each tie point, as well as stratigraphic level and global positioning system (GPS) position of each paleosol, are in GSA Data Repository (see text footnote 1).

precipitation levels through the year, and nodules estimate from a paleosol represents a time- because an increase from 280 to 3080 ppmv thus form at various levels within the soil rather averaged climatic condition for the duration CO2 has been modeled (McFadden and Tinsley, in a narrow horizon as in less seasonal climates. of past soil development (2–16 k.y. for Utah- 1985) to increase depth to pedogenic carbonate Paleoclimatic dependence of depth and spread of Montana paleosols calculated from Eq. 6). only 5 cm. This results in a MAP increase of carbonate nodules in soils is independent of their Comparison with modern soils requires correc- only 25 mm for carbonate depth of 50 cm and size, which increases with time of soil devel- tion of depth to calcic horizon in paleosols for 18 mm for carbonate depth of 100 cm: both well opment from small wisps of carbonate to large burial compaction using standard algorithms within standard error of Equation 2. nodules and ultimately thick tabular carbonate (Sheldon and Retallack, 2001) and geological Geochemical proxies for paleoclimate would horizons (Retallack, 2005a). estimates of overburden from local stratigraphic have been compromised by burial alteration if Caveats for application of these climofunc- sequences (Hintze, 1988). Correction for higher there had been widespread infl ux of alkali and tions include the following. A paleoclimatic than modern atmospheric CO2 was not applied, alkaline-earth elements due to metamorphism

1446 Geological Society of America Bulletin, September/October 2009 Past greenhouse crises

paleoclimatic events would be easy to miss in Interpretation of Paleoclimatic Anomalies long uneven records. There is also the prob- A lem of identifying climatic events within back- Paleoprecipitation spikes are statistical out- D BkBk T ground noise. liers (Fig. 7), but they are also real events of A The paleoprecipitation proxy of depth to the past. They are visible in outcrop as later- D calcic horizon in the paleosols (Figs. 4C) has ally extensive, clayey, deep calcic paleosols, BkBk T the highest resolution of the proxy records which form recessive-weathering, red marker presented here (3718 measurements over beds among the thousands of nodular pink and D A 300 m.y.): geochemical proxies do not show gray paleosols exposed in semiarid badlands of comparable temporal detail because of the ex- the Colorado Plateau (Fig. 8). Individual deep BkBk T pense of analyses. If peaks are defi ned as log- calcic paleosol intervals and inferred warm-wet transformed depths to calcic horizon more than spikes are named here by their correlative inter- two standard deviations above an 8 m.y. running national stages (Gradstein et al., 2004). Late Figure 6. Field appearance of measured mean, then there have been 40 paleoprecipita- Thanetian (latest Paleocene) and early Lute- depth to carbonate nodules and thickness tion spikes in the past 300 m.y. (Fig. 7; Table 2). tian (early-middle Eocene boundary) deep cal- of paleosols with carbonate nodules, upper Log transformation was required because of cic paleosols (Fig. 8A) can be traced from the Chinle Group, near Hog Springs, Utah (local- log-normal distribution of the measured depths, Gunnison Plateau of Utah (localities 38–39 of ity 9 of Fig. 4). Labels A and Bk are for soil which arises largely from proportions of cli- Fig. 4) east into the Piceance Basin of Colorado surface (A) and calcareous nodular (Bk) hori- mate modes representing Milankovitch-scale (east of locality 40). Late Norian (latest Tri- zons, and depth to Bk (D) and thickness of periods (Retallack, 2007). The 8 m.y. used as assic) and early Toarcian (late Early Jurassic) soils with nodules (T) are the two measures a running mean represents observed ±4 m.y. deep calcic paleosols (Fig. 8B) are traceable for each paleosol reported here. maximal uncertainty in radiometric dating of throughout southern Utah from Gunlock (local- geological stage boundaries (Gradstein et al., ity 13 of Fig. 4) through Kanab (locality 11), 2004). The 40 paleoclimatic spikes are not a to Hog Springs (locality 9) and Moab (local- (Frey, 1987). Studies of the lower part of the statistical artifact of normalization, because ity 27). Permian deep calcic paleosols (Figs. sequence (Cutler, Moenkopi, Chinle and Morri- a computed normal distribution with the same 8C–8D) crop out over a large area of iconic son Formation) show illite-smectite mixtures, mean and standard deviation has 102 of the western scenery from near Mexican Hat (local- where smectite is more closely related to vol- 3718 paleosols higher than two standard devia- ity 1) to Monument Valley (near locality 3) and canic infl ux than stratigraphic level (Keller, tions from the mean. As can be seen from var- Canyonlands National Park (locality 7). Eolian 1959; Jennings and Hasiotis, 2006). Large- iation in width of gray spikes in Figure 7, most erg deposits such as the DeChelly, Navajo, and scale leaching and mineralization of the Navajo of the 40 spikes are represented by more than Wingate Sandstones (Hintze, 1988) are associ- Sandstone has been proposed in southeastern one deep calcic paleosol. ated with shallow-calcic paleosols of arid lands, Utah (Bowen et al., 2007), but leached and nod- ular zones were not seen in the sections studied here with paleomagnetic (Johnson, 1976) and radiometric data (Fillmore, 1989; Goldstrand 2.4

a

cm)

99 Ma et al., 1993; Kowallis et al., 2001), near Gun- Ma

39 Ma Ma

a 10

240 Ma

203 Ma

5 M

Ma

150 Ma

9 Ma

217 Ma 2.2 169 Ma 66 Ma

3

4 Ma

82 Ma

3 Ma

4 lock, southwest Utah. Local roll-type uranium 103

181 Ma

228 Ma

6 Ma

Ma

112

16

9

30 Ma

237 Ma

11

152 Ma

55 Ma

270 Ma

19 M

14

164 Ma mineralization of wood and sandstone is well 299 Ma

297 Ma

292 Ma 249 Ma

110

276 Ma

252 Ma

24 Ma

245 Ma

2 1

known in the Coconino, Shinarump, Chinle, 6 Ma

259 Ma

30 Ma and Morrison Formations of the Colorado 13

1

193 Ma

280 Ma Plateau (Granger et al., 1988), but it was not en- 1.8 countered at the outcrops studied. None of these sections showed evidence of metamorphism, 1.6 despite 6 km of cumulative section (Fig. 4), because of widespread cutting and fi lling, and 1.4 localization of synorogenic depocenters (Gold- strand et al., 1993; Loope et al., 2004). 1.2

Statistical Defi nition of Paleoclimate Spikes Log-transformed Bk depth (log 1 The paleoclimatic proxies are spiky (Fig. 4). 300 250 200 150 100 50 0 A problem with such records is identifying Age (Ma) spikes, because previous carbon isotope (δ13C) and stomatal index studies of early Gries bachian Figure 7. Running mean (±4 m.y.) by million-year increments and two-standard-deviation (Retallack et al., 2006), late Norian (McElwain envelope of log-transformed depth to calcic horizon in paleosols of Utah and Montana. The et al., 1999), and early Toarcian (McElwain et al., 40 peaks (gray spikes) representing unusually humid paleoclimate in excess of two standard deviations (black error envelope) are marked with geological ages and listed in Table 2. 2005) sequences have revealed that some CO2 transients were only a few hundred thousand Calcic depths at the other extreme, below two standard deviations represent unusually arid years in duration. Other comparably short-term paleoclimate or highly eroded paleosols.

Geological Society of America Bulletin, September/October 2009 1447 Retallack

to bolide impact (Alvarez et al., 1980), fl ood basaltic volcanism (Courtillot and Renne, 2003), early Lutetian COLTON methane clathrate release (Dickens et al., 1995), and coal intrusion (McElwain et al., 2005). FLAGSTAFF NAVAJO These particular events of the past have long been marked as abrupt geochemical and biotic late Thanetian early Toarcian KAYENTA crises in the ocean, punctuating long and un- NORTH HORN eventful times. “In other words, the history of MOENAVE any one part of the Earth, like the life of a soldier, late Norian CHINLE consists of long periods of boredom and short periods of terror” (Ager, 1973, p. 100). New records provided here show they were also times A B of abrupt warm-wet paleoclimatic shifts on land and spikes in atmospheric CO2.

Paleogeographic and Tectonic Infl uences? MOENKOPI

disconformity Paleogeographic changes over the past early Roadian 300 m.y. are a competing explanation for paleo- CEDAR MESA climatic variation in Utah and Montana. All the sites were in fl uvial-eolian lowlands inland from the coast (Loope et al., 2004). The Four Corners state intersection in the southeastern part of the ORGAN ROCK study area (Fig. 4) was tropical, drifting north- early Sakmarian early Kungurian ward from a paleolatitude of 5°N in the Early HALGAITO Permian (275 Ma) to 9°N in the late Early Juras- sic (175 Ma), then remaining close to 9°N until C D middle Asselian the mid-Cretaceous (100 Ma). Drift through sub- tropical to temperate latitudes to the current 37°N Figure 8. Scenic deep calcic paleosols in selected formations (all capitals). (A) Late Thanetian occurred after the Jurassic-Cretaceous stillstand and early Lutetian subhumid paleosols dividing arid paleosols in cliffs of Axhandle Canyon, (Beck and Housen, 2003; Rowe et al., 2007). Utah (site 38 of Fig. 4). (B) Late Norian and early Toarcian subhumid paleosols dividing eolian Throughout the past 300 m.y., principal wind dune facies and semiarid paleosols in cliffs north of Ivins, Utah (site 10 of Fig. 4). (C) Early directions over North America were westerly Kungurian and early Roadian subhumid paleosols among semiarid paleo sols below the (Swinehart et al., 1985; Gustavson and Holli- Triassic-Permian disconformity near Hite, Utah (locality 3 of Fig. 4). (D) Early Sakmarian day, 1999; Loope et al., 2004), and the Colorado and middle Asselian subhumid paleosols among arid paleosols and braided stream deposits Plateau and southwestern Montana were in rain in cliffs of Moki Dugway, north of Mexican Hat, Utah (site 1 of Fig. 4). shadows of Permian-Jurassic volcanic arcs and the Cretaceous-Cenozoic Cordillera (Hintze, 1988). In addition to persistent rain-shadow whereas marine transgressions of the Kaibab, fi ne not only the basal Mesozoic and Cenozoic, paleogeography, only calcareous paleosols were Moenkopi, Carmel, and Dakota Formations are but many of the 39 Permian-Cretaceous inter- studied, and, today, these are limited to regions associated with deep calcic paleosols of sub- national stages and six epochs of the Cenozoic with 300–1000 mm mean annual rainfall (Retal- humid paleoclimates (Fig. 4). (Gradstein et al., 2004). lack, 2005a). Noncalcareous paleosols also are The 40 key events of environmental pertur- Times of oceanic anoxia and exceptional found in the sequence, notably in near-marine bation represented by deep calcic paleosols in fossil preservation (black shales and lager stätten, facies of the Dakota Formation in Utah (Hintze, Utah and nearby states are already well known or “motherlode” fossil beds, of Table 2) are also 1988), and so for that time interval, observa- in high-resolution marine sequences, where represented. Mirroring the short-term pertur- tions were made further west in the Baseline they are defi ned in sedimentary sequences with bation of calcic paleosols (Figs. 4 and 8), the Sandstone at Valley of Fire, southeast Nevada continuous sedimentation (Gradstein et al., most organic parts of marine black shales are (locality 30 in Fig. 4; Table 1). Paleogeographic 2004). Major episodes of marine mass extinc- thin (Wignall, 1994; Jenkyns et al., 2002), and and paleolatitudinal change may explain broad tion are represented (260 Ma end-Guadalupian, marine fossil lagerstätten within these black trends in the data (Figs. 4B–4C) but not the con- 252 Ma end-Permian, 203 Ma Late Norian, 93 Ma shales are restricted to few bedding planes (Etter, spicuous paleoclimatic spikes. early Turonian, and 66 Ma end-Cretaceous: 2002b; Etter and Tang 2002; Fara et al., 2005). Peters , 2006). Two of these mass extinctions Most of these times are also carbon cycle crises , CORRELATING PALEOCLIMATIC were already recognized from nonmarine ver- represented by sharp fl uctuations in carbon AND CO2 RECORDS tebrates in the Colorado Plateau: Late Norian isotopic composition of sea shells, soil caliche (Lucas and Tanner, 2007) and end-Cretaceous nodules, and plant organic matter (Jenkyns et al., Pedogenic records of paleoclimate are spiky: (Difl ey and Ekdale, 1999). Anomalously deep 2002; Jenkyns, 2003; Retallack, 2005b; Retal- both as raw observations (Figs. 4B–4C) and as calcic paleosols now allow wider recognition of lack et al., 2006; Montañez, et al., 2007). These transformed paleoclimate records (Fig. 9). The these and other biotic events. The 40 events de- 40 key times have been variously attributed less continuous record of past atmospheric CO2

1448 Geological Society of America Bulletin, September/October 2009 Past greenhouse crises

TABLE 2. OUTLIER PEAKS IN DEPTH TO Bk HORIZON (D) IN PALEOSOLS OF defi ned a priori, at increments of ±2 and ± 4 m.y. UTAH AND MONTANA, AND COEVAL OCEANIC ANOXIA EVENTS (OAE) AND LAGERSTÄTTEN (see GSA Data Repository [see footnote 1]), Age Geological age Marine black shales Lagerstätten Log10D Log10D> (Ma) (reference footnote) (reference footnote) peak 2σ which are more appropriate to the dating reso- 16 Early Langhian Monterey Shale (1) Clarkia (31) 1.622 0.117 lution (Gradstein et al., 2004) than the ±1 and 19 Middle Burdigalian Upper Dysodilic Shale (2) Rio Rubielos (32) 1.627 0.119 ±2 yr increments used in annual data (Prager 30 Late Rupelian Riki Horizon (3) Bechlejovice (33) 1.720 0.008 35 Late Priabonian Lower Dysodilic Shale (4) Florissant (34) 1.787 0.045 and Hoenig, 1989). Distribution of the Prager- 39 Early Bartonian Chapelcorner Fish Bed (5) Chapelcorner (5) 1.789 0.310 Hoenig W statistic was estimated by 10,000 49 Early Lutetian Abbotsford Mudstone (6) Messel (35) 1.711 0.003 iterations of a data table with random numbers 55 Late Thanetian Mo Clay (7) Fur (7) 1.690 0.061 66 Early Danian Zumaya boundary bed (8) Worli Hill (36) 1.728 0.062 within the range of observed values from the 82 Early Campanian Pierre Shale (9) Elkader (37) 1.838 0.099 Wichmann-Hill algorithm (Excel© electronic 93 Early Turonian Bonarelli-OAE (10) Quero (38) 1.865 0.001 99 Early Cenomanian Breistroffer-OAE (10) Haqel (39) 1.742 0.002 spreadsheet normal default). The W statis- 103 Late Albian Toolebuc-OAE (10) Tlayua (40) 1.699 0.006 tic from the normal distribution of the 10,000 110 Middle Albian Urbino-OAE (10) Santana (41) 1.668 0.017 itera tions for comparison of Ginkgo-CO and 112 Early Albian Paquier-OAE (10) Crato (41) 1.704 0.002 2 114 Late Aptian Jacob-OAE (10) Chaomidian(42) 1.717 0.011 paleosol Bk data was 394, indicating that the 124 Early Aptian Selli-OAE (10) Sihetun (42) 1.647 0.113 null hypothesis of nonsynchroneity has a slim 130 Late Hauterivian Faraoni-OAE (10) Las Hoyas (43) 1.617 0.005 probability of 0.014 (see GSA Data Repository 136 Late Valanginian Weissert-OAE (11) Montsec (44) 1.610 0.001 146 Early Berriasian Janusfjellet Formation (12) Swanage (45) 1.698 0.066 [see footnote 1]). The null hypothesis of non- 150 Early Tithonian U. Kimmeridge Clay (13) Solnhofen (46) 1.716 0.113 synchroneity is thus rejected. 152 Late Kimmeridgian L.Kimmeridge Clay (13) Cerin (47) 1.713 0.120 The CO and paleoclimatic parameters of 164 Early Callovian Oxford Clay (13) La Voulte (48) 1.595 0.128 2 169 Middle Bajocian Ohautira Formation (14) Schinznach (49) 1.652 0.115 the 20 correlated peaks and for 32 additional 181 Early Toarcian Posidonienschiefer (15) Holzmaden (15) 1.541 0.141 off-peak intervals used in superposed epoch 193 Middle Sinemurian Lombardische Kieselkalk (16) Osteno (16) 1.505 0.057 analysis give a data set of 52 time intervals for 203 Late Norian Argilliti di Riva di Solto (17) Bergamo (17) 1.782 0.002 217 Late Carnian Cow Branch Formation (18) Solite (18) 1.788 0.069 investigation of the role of CO2 in paleoclimate. 228 earliest Carnian Xiaowa Formation (19) Wayao (19) 1.724 0.102 These 52 values can now be used for correla- 237 earliest Ladinian Grenzbitumen (20) Mt. San Giorgio (20) 1.753 0.001 tions between CO and paleoclimatic param- 240 Middle Anisian Guanling Formation (21) Xinmin (21) 1.682 0.006 2 245 Late Spathian Vikinghøgda Formation (22) Hangviller (50) 1.695 0.038 eters (Fig. 10), and they can be evaluated with 249 Early Smithian Blind Fiord Formation (23) Wapiti Lake (51) 1.693 0.001 Student’s t-test for unequal variances using 252 Early Griesbachian Wordie Creek Formation (24) Ambilobe (52) 1.699 0.044 259 Early Wuchaipingian Kupferschiefer (25) Bad Sachsa (26) 1.582 0.122 log-transformed data because of the log-normal 270 Early Roadian Phosphoria Formation (26) Koštálov (53) 1.694 0.059 distribution of all variables. The possibility that 276 Early Kungurian Lontras Shale (27) Tschekarda (54) 1.633 0.050 apparent correlation of the two records was due 280 Middle Artinskian Quinnanie Shale (28) Worcester (55) 1.563 0.056 292 Early Sakmarian Holmwood Shale (29) Elmo (54) 1.595 0.158 to autocorrelation of highly variable records 297 Middle Asselian M. Neal Ranch Form. (30) Odernheim (56) 1.582 0.140 with a peak for every occasion was ruled out 299 Early Asselian L. Neal Ranch Form. (30) Gottlob (57) 1.586 0.034 by low correlation of offset portions of the time References: 1. Isaacs (1989); 2. Constantin (2000); 3. Fedotov (1974); 4. Baciu (1998); 5. Gaudant and Quayle (1988); 6. Fordyce (1991); 7. Bonde (1997); 8. Smit (1999); 9. Taverne (2004); 10. Gradstein et al. series. This statistical test also confi rms obser- (1984); 11. Erba et al. (2004); 12. Hvoslef et al. (1986); 13. Wignall (1994); 14. Westermann et al. (2000); 15. vation that the key events are not uniformly dis- Etter and Tang (2002); 16. Tang (2002); 17. Tintori (1996); 18.Olsen and Johanessen (1994); 19. Hagdorn et tributed through time, but instead are separated al. (2007); 20. Etter (2002b); 21. Jiang et al. (2005); 22. Galfetti et al. (2007); 23. Tozer (1967); 24. Bjerager et al. (2006); 25. Brandt (1996); 26. Piper and Perkins (2004); 27. Ianuzzi and Souza (2005); 28. Haig (2003); by unequal intervals. 29. Mory and Iasky (1996); 30. Ross and Ross (1995); 31. Smiley (1985); 32. Wegierek and Peñalver (2002); 33. Spinar (1972); 34. Meyer (2003); 35. Schaal and Ziegler (1992); 36. Ribeiro (1921); 37. Bottjer (2002); 38. Gomez et al. (2002); 39. Poyato-Ariza and Wenz (2005); 40. Gonzalez-Rodriguez et al. (2004); 41. Fara et al. Power Laws for Climatic Response to (2005); 42. Zhou et al. (2003); 43. Evans and Barbadillo (1999); 44. Evans et al. (2000); 45. Rasnitsyn et al. CO2 Forcing (1998); 46. Etter (2002c); 47. Gaillard et al. (2003); 48. Charbonnier et al. (2007); 49. Hess (1999); 50. Etter (2002a); 51. Schaeffer and Mangus (1976); 52. Ketchum and Barrett (2004); 53. Milner (1981); 54. Grimaldi and Engel (2005); 55. MacRae (1999); 56. Witzmann and Pfritzschner (2003); 57. Gand et al. (1996). Climatic response to past CO2 forcing is re- vealed by cross-correlation of peaks and troughs

in the CO2 and paleoclimatic time series, which are now taken as statistically synchronous also shows spikes (Fig. 9), here defi ned as val- Testing for Synchroneity of Records (Fig. 10). Chemical proxies for precipitation ues greater than a standard deviation composed and temperature and carbonate proxy for pre- of preceding and following stomatal index The hypothesis to be tested is that 20 atmo- cipitation were signifi cantly correlated with CO2 determinations. These records could be tests spheric CO2 spikes evident from the stomatal (Student’s t-test probability <0.05), but there of greenhouse mechanisms for paleoclimatic index were coeval with 20 of the 40 spikes in was no signifi cant relationship with mean an- change, if it could be shown that the spikes from depth to pedogenic carbonate in Utah. This nual range of precipitation. Few of the paleosols separate stomatal and paleosol records were and the null hypothesis of nonsynchroneity of had a wide spread of carbonate nodules within indeed synchronous, and if cross correlation of spikes of CO2 and depth to carbonate is test- the profi le such as that found in monsoonal soils paleoclimatic and CO2 variation were statisti- able by super posed epoch analysis (Prager and (Retallack, 2005a), so this study does not sup- cally signifi cant. Of the 40 outlier paleoclimatic Hoenig, 1989), a nonparametric running-mean port the idea of “Pangean megamonsoons” equal events, only 20 (gray bars in Fig. 9) were de- technique suitable for comparing incomplete to or greater than the modern Indian monsoon as tected also by the Ginkgo CO2 paleobarometer, data such as the Ginkgo paleobarometer with far north in North America as Utah (Kutzbach which has gaps due to vagaries of cuticular fos- expectations from more complete data such as and Gallimore, 1989). In summary, warm spikes sil preservation that do not apply to the paleosol the paleosol record. The test is based on com- were not more seasonal, but warmer times were record (Retallack, 2007). parison of values before and after the key events also more humid, in accord with the view that

Geological Society of America Bulletin, September/October 2009 1449 Retallack

PERMIAN TRIASSIC JURASSIC CRETACEOUS CENOZOIC

Ma

82 Ma ian 55 Ma 55 ian

rriasian 146 Ma

Figure 9. Paleoclimatic and iabonian 35

Aptian 114 Ma Aptian 114 CO2 time series. (A) Atmo-

rly Campanian

early Tithonian 150 Ma Tithonian early

early Sakmarian 292 Ma early Roadian 270 Ma Ma 124 Aptian early early Toarcian 181 Ma 181 Toarcian early

early Be eary Langhian 16 Ma 16 Langhian eary

early Griesbachian 251 Ma 251 Griesbachian early early Carnian 228 Ma 228 Carnian early late early Wuchaipingian 259 Ma 259 Wuchaipingian early late Carnian 217 Ma mid-Bajocian 169 Ma spheric CO (ppmv) inferred late Pr

early Danian 65 Ma

late Norian 203 Ma 203 Norian late 93 early Turonian Ma late Thanet late 2 ea Ma 49 Lutetian early from stomatal index of Ginkgo 10,000 A and related fossil plants ac- 8,000 cording to two data quality 6,000

(ppmv) protocols (closed and open 2 4,000

symbols are based on >500 CO 2,000 cells, but open symbols are 0 300 250 200 150 100 50 0 based on less than fi ve leaves). 25 (B) Mean annual temperature 20 B (MAT in °C) inferred from 15 chemical salinization index of 10 paleosols (Sheldon et al., 2002). 5

Mean annual paleo- (C) Mean annual precipitation temperature (°C) 0 (MAP in mm) inferred from 300 250 200 150 100 50 0 chemical index of alteration of 2,000 C paleosols (Sheldon et al., 2002). 1,600 (D) MAP (mm) inferred from 1,200 compaction-corrected depth 800 to calcic horizon in paleosols 400 (Retallack, 2005a). (E) Mean 0 annual range of precipitation 300 250 200 150 100 50 0 1,200 (MARP, in mm) inferred from D compaction-corrected thick ness 1,000 of paleosol with nodules (Retal- 800 lack, 2005a). Error envelopes 600 in A are from standard devia- tion of individual stomatal in- 400

Mean annual paleoprecipitation (mm) dex measurements, but errors 200 in B–E are standard errors of 0 transfer functions discussed in 300 250 200 150 100 50 0 140 the text. E 120 100 80 60 40 20 0

Mean annual range of paleoprecipitation (mm) 300 250 200 150 100 50 0 Age (Ma)

warmer air has a greater moisture capacity to subhumid rain shadow east of North Ameri- ice-cap effect is not obvious, and these power (Alley et al., 2007). can volcanic arcs and cordilleras (Hintze, 1988; laws are a new approach to predicting future cli-

This empirical approach to past climate forc- Loope et al., 2004). One difference from today’s matic response to CO2 forcing. ing can be used to predict future climate response world is that most of the 300 m.y. record was from to atmospheric CO2 (Fig. 10), although it is a world free of large ice caps (Montañez et al., Visions of Past Climate limited to the region and environments on which 2007). Antarctic ice caps were present through it is based. All the paleosols studied were in sedi- the Early Permian and Oligocene-Pliocene , and High-resolution paleosol records now indi- mentary lowland environments, not much above these data points (fi lled in Fig. 10) deviate less cate that timing is important when considering sea level, and in a tropical to temperate, semiarid from the power law than other points. Thus, an paleoclimates of the past. Eventful times of

1450 Geological Society of America Bulletin, September/October 2009 Past greenhouse crises

Power laws from Utah paleoclimate Future climate from emission scenario A2 Prospects for Future Climate 100100 11.411.4 1,0001000 A 11.211.2 D 900900 The power laws derived here (Fig. 10) can be y = 4.58x0.12 11.011 used to predict future climate for any given CO2 10.810.8 800800

(ppmv) level. Scenarios of future CO2 levels vary widely 10.610.6 2 700700 with assumptions such as human energy use and 10.410.4 CO2 population growth. A widely used future emis- 1010 10.210.2 600600 10.010 sion scenario, A2, is one of a very heterogeneous 500500 9.89.8 world with continued population growth (Alley 2 R = 0.25 9.69.6 400400 et al., 2007), and it predicts atmo spheric CO2 of t = 37.7 9.49.4 temperature 300300 856 +70/–101 ppmv by the year 2100. Climatic p < 0.0001 9.29.2 ISAM model CO consequences of this model can be estimated 100001 9 200 Mean annual temperature (°C) 800 E 1000 from the power laws. Errors of these estimates 100B 1000y = 54.1x0.37 10000 100000 2000 2020 2040 2060 2080 2100 900900 shown in Figure 10 are from the envelope of 750 800800 scenarios (Alley et al., 2007), rather than from

(ppmv) 700 700 2 1,0001000 CO2 700 the errors of transfer functions used for predic- 650 600600 tion. A baseline for these estimates is the value 500500 predicted by the power laws for 280 ppmv, the 600 600 400400 preindustrial level (Alley et al., 2007). Moun- 100100 R 2 = 0.39 550 300300 tainous Utah currently has a variety of micro- t = 2.07 precipitation 200200 climates, but the climate predicted by the power

500 ISAM model CO p = 0.04 100100 laws for 280 ppmv is closest to that historically

Mean annual precipitation (mm) from CIA-K 1000010 450 0 recorded from Manti, Utah (Ruffner, 1978). 800 1000 100C 1000 10000 100000 2000F 2020 2040 2060 2080 2100 The projected increase in temperature by 2100 900900 750750 for areas with climate like Manti from the em- 800800 y = 105.5x0.26 pirical power laws is low (+1.2 °C), but close

700 (ppmv) 700 CO2 700700 2 to theoretical global models (Alley et al., 2007; 600600 650650 +2.4 °C, with range from 1.4 to 3.8 °C). Local 1,0001000 500500 600 temperature sensitivity (MAT change with CO 600 400400 2 doubling) using these empirical power laws also 2 300 R = 0.55 550550 300 is low (0.8 °C) compared with global sensitivity t = 6.79 precipitation 200200 500500 estimates (1.5–6.2 °C) from theoretical models 100100 p < 0.0001 ISAM model CO of past and present climate (Royer et al., 2007).

Mean annual precipitation (mm) from Bk 100100 450450 0 Precipitation sensitivity (MAP increase for CO 1001001,000 1000 10,000 10000100,000 100000 20002020 20202040 20402060 20602080 2080 2100 2 doubling) is 89 mm for calcic horizon estimates Past atmospheric CO2 (ppmv) Future year and 128 mm for geochemical estimates. Underestimation of climatic response to Figure 10. Empirical power laws relating past climate and atmospheric CO2. (A–C) Atmo- atmo spheric CO2 forcing compared with global spheric CO2 for 52 adequately sampled intervals (Fig. 1) from stomatal index of Ginkgo and related taxa as independent variable. Open symbols are for a largely ice-free world (late models could be due to either local or nonlinear Permian to Eocene); fi lled symbols are for a world with a large Antarctic ice cap (Oligo cene responses. Changes in both rainfall and tempera- to Pliocene and Early to Middle Permian). (A) Mean annual temperature (MAT) calculated ture predicted from climate modeling of future from chemical salinization index of paleosols. (B–C) Mean annual precipitation (MAP) global warming are less for Utah than for other calculated from compaction-corrected depth to calcic horizon in paleosols (B) and from parts of the world, such as polar regions (Alley potash-free chemical index of alteration (C). (D–F) Predicted climate change by the year et al., 2007). The projected rise in precipitation and range of precipitation is compatible with 2100 using power laws of A–C, and concentrations of CO2 (gray curves) from Integrated Science Assessment Model (ISAM) (Alley et al., 2007) of emission scenario A2. Error enve- vegetation predictions for 2100, which state lopes in D–F include other emission scenarios. that Utah desert shrubland will be replaced by grassland (Diffenbaugh et al., 2003). There could also be unmodeled mechanisms mitigat- ing extreme climate change, such as cloud cover short-term climate variation such as the Early with hot fl ashes. The concept of a uniformly (Lin et al., 2002), glacial ablation (Clark et al.,

Permian, Early Triassic, Middle-Late Jurassic, high-CO2 and hot Mesozoic greenhouse can 1999), or soil carbon sequestration and con- Cretaceous, and Eocene are interspersed with now be seen to be due to paucity of data (Frakes sumption (Retal lack, 2004). Such compensa- stable times such as the Late Permian, Middle et al., 1992) or modeling steps too large (10 m.y.) tory mechanisms may have been nonlinear, i.e.,

Triassic, Paleocene, and Oligocene. Late Paleo- to capture short-term variability (Berner, 2006). more effective during extreme than modest CO2 zoic climate was generally cool, but it had sev- It is no longer reasonable to view “Triassic cli- forcing events of the geological past, or more ef- eral warm-wet spikes (Retallack, 2005b), each mate” as if it were static: Utah and surrounding fective over short than long time scales. At the shorter in duration than envisaged by Montañez areas experienced dramatic short-term perturba- Permian-Triassic boundary (Retallack et al., et al. (2007). The Mesozoic greenhouse was not tions as well as long-term paleoclimatic changes 2006), for example, global havoc did not con- hot with cool spells (Royer, 2006), but warm during the Triassic and other periods. tinue with runaway positive feedback to a lifeless

Geological Society of America Bulletin, September/October 2009 1451 Retallack greenhouse like that of our sister planet Venus Anderson, J.M., and Anderson, H.M., 1989, Palaeofl ora of Clark, P.U., Alley, R.B., and Pollard, D., 1999, Northern Southern Africa, Molteno Formation (Triassic). Vol- Hemisphere ice-sheet infl uences on global climate (Kasting and Catling, 2003). In addition, varia- ume 2: Gymnosperms (excluding Dicroidium): Rotter- change: Science, v. 286, p. 1104–1111, doi: 10.1126/ bility in CO2 recorded by the stomatal index of dam, A.A. Balkema, 567 p. science.286.5442.1104. seasonally deciduous leaves may not be recorded Augustin, L., and 55 others, 2004, Eight glacial cycles from Constantin, P., 2000, The Oituz Valley: A new fossilifer- an Antarctic ice core: Nature, v. 429, p. 623–628, doi: ous locality with lower Miocene ichthyofauna in the in multimillennial proxies from paleosols. 10.1038/nature02599. Romanian eastern Carpathians: Revue Roumaine de Baars, D.L., 1987, Late Paleozoic–Mesozoic stratigraphy, Geologie, v. 44, p. 51–55. CONCLUSIONS Hite region, Utah, in Beus, S.S., ed., Centennial Field Courtillot, V.E., and Renne, P.R., 2003, On the ages of fl ood Guide, Rocky Mountain Section: Boulder, Geological basalt events: Comptes Rendus Academie des Sci- Society of America, p. 281–288. ences Geoscience, v. 335, p. 113–140, doi: 10.1016/ If past performance is a guide to future per- Baciu, S., 1998, On the presence of Zenopsis clarus (tele- S1631-0713(03)00006-3. ostean fi sh, Zeidae) from the Oligocene Tarcau Nappe: Croes, M.C., 1978, Magnetostratigraphy of the Ankareh and formance, the geological record of past climate Revue Roumane de Geologie, v. 42, p. 43–49. Chinle Formations [M.Sc. thesis]: Salt Lake City, Uni- change could be useful in evaluating future Bakker, R.T., 1998, Dinosaur mid-life crisis: The Jurassic- versity of Utah, 226 p. response of climate to anthropogenic carbon Cretaceous transition in Wyoming and Colorado, in David, T.W.E., 1907, Conditions of climate at various geo- Lucas, S.G., and Estep, J.W., eds., Lower and Middle logical epochs: Mexico City, Tenth International Geo- dioxide emissions. Using records of past climate Cretaceous Terrestrial Ecosystems: Bulletin New logical Congress, v. 1, p. 271–274. in this way is an empirical rather than model- Mexico Museum of Natural History and Science, v. 14, Dickens, G.R., O’Neil, J.R., Rea, D.K., and Owen, R.M., ing approach to climate forecasting. Deep-time p. 67–77. 1995, Dissociation of oceanic methane hydrate as a Beck, M.E., and Housen, B.A., 2003, Absolute velocity cause of the carbon isotope excursion at the end of the records, here taken back 300 m.y., enhance pre- of North America during the Mesozoic from paleo- Paleocene: Paleoceanography, v. 10, p. 965–971, doi: diction by including conditions beyond those magnetic data: Tectonophysics, v. 377, p. 33–54, doi: 10.1029/95PA02087. found during the Quaternary. Soaring levels 10.1016/j.tecto.2003.08.018. Diffenbaugh, N.S., Sloan, L.S., Snyder, M.A., Bell, J.L., Beerling, D.J., and Royer, D.L., 2002, Reading a CO2 sig- Kaplan, J., Shafer, S.L., and Bartlein, P.J., 2003, Vege- of atmospheric carbon dioxide well in excess of nal from fossil stomata: The New Phytologist, v. 153, tation sensitivity to global anthropogenic carbon di- pre dictions for the next century (865 ppmv CO : p. 387–397, doi: 10.1046/j.0028-646X.2001.00335.x. oxide emissions in a topographically complex region: 2 Beerling, G.J., McElwain, J.C., and Osborne, C.P., 1998, Global Biogeochemical Cycles, v. 17, p. 36–44, doi: Alley et al., 2007) are known in deep time, al- Stomatal responses of the “living fossil” Ginkgo biloba 10.1029/2002GB001974. though levels in excess of 2000 ppmv were all L. to changes in atmospheric CO2 concentrations: Jour- Difl ey, R., and Ekdale, A.A., 1999, Biostratigraphic aspects associated with signifi cant mass extinctions, and nal of Experimental Botany, v. 49, p. 1603–1607, doi: of the Cretaceous-Tertiary (K-T) boundary interval 10.1093/jexbot/49.326.1603. at North Horn Mountain, Emery County, Utah, in life was almost entirely extirpated under some Berner, R.A., 2006, Inclusion of the weathering of vol- Gillette , D.D., ed., Vertebrate Paleontology in Utah: 7200 ppmv at the Permian-Triassic boundary canic rocks in the GEOCARBSULF model: Ameri- Utah Geological Survey Miscellaneous Publication can Journal of Science, v. 306, p. 295–302, doi: v. 1999–1, p. 389–398. (252 Ma: Retallack et al., 2006). Past climatic 10.2475/05.2006.01. Eaton, J.G., Diem, S., Archibald, J.D., Schierup, C., and responses to CO2 forcing support key predic- Bjerager, M., Seidler, L., Stemmerik, L., and Surlyk, F., Munk, H., 1999, Vertebrate paleontology of the Upper tions of greenhouse theory: climate became 2006, Ammonoid stratigraphy and sedimentary evo- Cretaceous rocks of the Markugunt Plateau, southwest- lution across the Permian-Triassic boundary in East ern Utah, in Gillette, D.D., ed., Vertebrate Paleontol- warmer and wetter in proportion to higher levels Greenland: Geological Magazine, v. 143, p. 635–656, ogy in Utah: Utah Geological Survey Miscellaneous doi: 10.1017/S0016756806002020. Publication 1999–1, p. 323–334. of atmospheric CO2. Paleoclimatic results pre- sented here apply only to mid-latitude, mid- Blakey, R.C., Basham, E.L., and Cook, M.J., 1993, Early and Ekstrand, E.J., and Butler, R.F., 1989, Paleomagnetism of Middle Triassic paleogeography of the Colorado Plateau the Moenave Formation: Implications for the Meso- continental, summer-wet regions such as Utah, and vicinity, in Morales, M., ed., Aspects of Mesozoic zoic North American apparent polar wander path: where they were based. The agreement of these Geology and Paleontology of the Colorado Plateau: Geology, v. 17, p. 245–248, doi: 10.1130/0091-7613 Museum of Northern Arizona Bulletin, v. 59, p. 13–26. (1989)017<0245:POTMFI>2.3.CO;2. results with modeling results suggests they may Bonde, N., 1997, A distinctive fi sh fauna from the basal Erba, E., Bartolini, A., and Larson, R.L., 2004, Valanginian be representative of other regions as well, and Ash-Series of the Fur/Ølst Formation (U. Paleocene, Weissert oceanic anoxic event: Geology, v. 32, p. 149– there is potential to extend such techniques to Denmark), in Thomsen, E., and Pedersen, S.A.S., eds., 152, doi: 10.1130/G20008.1. Geology and Paleontology of the Mo-clay: Aarhus Etter, W., 2002a, Gres a Voltzia: Preservation in early other long paleosol sequences elsewhere. Geoscience, v. 6, p. 33–48. Mesozoic deltaic and marginal marine environments, Bottjer, D.J., 2002, Smoky Hills Chalk: Spectacular Cre- in Bottjer , D.J., Etter, W., Hagadorn, J.W., and Tang, ACKNOWLEDGMENTS taceous marine fauna, in Bottjer, D.J., Etter, W., C.M., eds., Exceptional Fossil Preservation: A Unique Hagadorn, J.W., and Tang, C.M., eds., Exceptional View of the Evolution of Marine Life: New York, Co- Lisa Emerson and Brooks Britt helped during fi eld Fossil Preservation: A Unique View of the Evolution lumbia University Press, p. 205–220. of Marine Life: New York, Columbia University Press, Etter, W., 2002b, Monte San Giorgio: Remarkable Triassic work, and Dan Gavin, Josh Roering, Pat Bartlein, and p. 353–364. marine vertebrates, in Bottjer, D.J., Etter, W., Hagadorn, Ben Cramer offered invaluable statistical advice. Tom Bowen, B.B., Martini, B.A., Chan, M.A., and Parry, W.T., J.W., and Tang, C.M., eds., Exceptional Fossil Preserva- Rich (Museum Victoria) and George Stanley (Uni- 2007, Refl ectance spectroscopic mapping of diagenetic tion: A Unique View of the Evolution of Marine Life: versity of Montana) facilitated loans of fossil Ginkgo heterogeneities and fl uid fl ow pathways in the Jurassic New York, Columbia University Press, p. 221–242. cuticles. The manuscript was greatly improved by Navajo Sandstone: The American Association of Petro- Etter, W., 2002c, Solnhofen: Plattenkalk preservation with reviews by Neil Tabor, Justin Ries, David Fox, Mark leum Geologists Bulletin, v. 91, p. 173–190. Archaeopteryx, in Bottjer, D.J., Etter, W., Hagadorn, Clementz, and Hope Jahren. This work was funded by Brandt, S., 1996, Janassa korni (Weigelt)—Neubesch- J.W., and Tang, C.M., eds., Exceptional Fossil Preser- a University of Oregon Summer Faculty Award. reibung eines petalodonten Elasmobranchiers aus dem vation: A Unique View of the Evolution of Marine Life: Kupferschiefer und Zechsteinkalk (Perm) von Eisleben New York, Columbia University Press, p. 327–352. (Sachsen-Anhalt): Paläontologische Zeitschrift, v. 70, Etter, W., and Tang, C.M., 2002, Posidonia Shale: Ger- REFERENCES CITED p. 505–520. many’s Jurassic marine park, in Bottjer, D.J., Etter, Caputo, M.V., 2003, Geology of the Paria Canyon– W., Hagadorn, J.W., and Tang, C.M., eds., Exceptional Ager, D.V., 1973, The Nature of the Stratigraphical Record: Vermillion Cliffs wilderness, Utah and Arizona, in Fossil Preservation: A Unique View of the Evolution New York, Wiley, 114 p. Sprinkel, D.A., Chudsey, T.C., and Anderson, P.B., of Marine Life: New York, Columbia University Press, Alley, N.F., and Frakes, L.A., 2003, First known Creta- eds., Geology of Utah Parks and Monuments: Utah p. 265–291. ceous glaciation: Livingston Tillite Member of the Geological Association Publication 28, p. 535–561. Evans, J.R., 1996, Synopsis of the Page Sandstone, in Cadna-owie Formation, South Australia: Australian Carpenter, D.G., and Carpenter, J.A., 1987, New K-Ar ages Morales, M., ed., Guidebook for the Geological Excur- Journal of Earth Sciences, v. 50, p. 139–144, doi: from the Baseline Sandstone (Cenomanian), north sion of the Continental Jurassic Symposium: Flagstaff, 10.1046/j.1440-0952.2003.00984.x. Muddy Mountains, Clark County, Nevada: Isochron- Museum of Northern Arizona, p. 41–47. Alley, R., and 32 others, 2007, Climate Change 2007: The West, v. 49, p. 3–4. Evans, S.E., and Barbadillo, L.J., 1999, A short-limbed Physical Science Basis: Geneva, Intergovernmental Charbonnier, S., Vannier, J., Gaillard, C., Bourseau, J.-P., lizard from the Lower Cretaceous of Spain, in Unwin, Panel on Climate Change, 1009 p. and Hantzpergue, P., 2007, The La Voulte Lagerstätte D.M., ed., Cretaceous Fossil Vertebrates: Palaeonto- Alvarez, L.W., Alvarez, W., Asaro, F., and Michel, H.V., (Callovian): Evidence for a deep water setting from logical Association, Special Papers in Palaeontology, 1980, Extraterrestrial cause for the Cretaceous Ter- sponge and crinoid communities: Palaeogeography, v. 60, p. 73–85. tiary extinction: Science, v. 208, p. 1095–1108, doi: Palaeoclimatology, Palaeoecology, v. 250, p. 216–236, Evans, S.E., Lacasa Ruiz, A., and Rey, E., 2000, A lizard 10.1126/science.208.4448.1095. doi: 10.1016/j.palaeo.2007.03.013. from the Early Cretaceous (Berriasian-Valanginian) of

1452 Geological Society of America Bulletin, September/October 2009 Past greenhouse crises

Montsec, Catalonia, Spain: Neues Jahrbuch für Geol- Traumatocrinus from southwest China: Palaeogeogra- Keller, W.D., 1959, Clay minerals in the mudstones of the ogie und Palaontologie Abhandlungen, v. 215, p. 1–15. phy, Palaeoclimatology, Palaeoecology, v. 247, p. 181– ore-bearing formations: U.S. Geological Survey Pro- Fara, E., Saraiva, A.A.F., de Almeida Campos, D., Moreira, 196, doi: 10.1016/j.palaeo.2006.10.020. fessional Paper 320, p. 113–119. J.K.R., de Carvalho Siebra, D., and Kellner, A.W.A., Haig, D.W., 2003, Palaeobathymetric zonation of forami- Ketchum, H., and Barrett, P.M., 2004, New reptile material 2005, Controlled excavation in the Romualdo Member nifera from Lower Permian shale deposits of a from the Lower Triassic of Madagascar; implications of the Santana Formation (Early Cretaceous, Araripe high-latitude southern interior sea: Marine Micro- for the Permian-Triassic extinction event: Canadian Basin, northeastern Brazil): Stratigraphic, palaeoenvi- paleontology, v. 49, p. 317–334, doi: 10.1016/ Journal of Earth Sciences, v. 41, p. 1–8, doi: 10.1139/ ronmental and palaeoecological implications: Palaeo- S0377-8398(03)00051-3. e03-084. geography, Palaeoclimatology, Palaeoecology, v. 218, Heer, O., 1868, Die fosile Flora der Polarländer, enhantend Kirkland, J.I., Britt, B.B., Whittle, C.H., Madsen, S.K., and p. 145–160, doi: 10.1016/j.palaeo.2004.12.012. die in Nordgrönland, auf der Melville-Insel, im Banks- Burge, D.L., 1998, A small coelurosaurian theropod Fedotov, V.F., 1974, New upper Oligocene Gadidae from the land, am Mackenzie, in Island, und in Spetzbergen en- from the Yellow Cat Member of the Cedar Mountain Caucasus: Paleontological Journal, v. 8, no. 4, p. 78–83. deckten fossilen Pfl anzen: Zürich, Wurster, 192 p. Formation (Lower Cretaceous, Barremian) of eastern Fillmore, R.P., 1989, Sedimentology and Provenance of the Helsley, C.E., and Steiner, M.B., 1974, Paleomagnetism of the Utah, in Lucas, S.G., Kirkland, J.I., and Estep, J.W., Upper Cretaceous Iron Springs Formation, southwest Lower Triassic Moenkopi Formation: Geological Soci- eds., Lower and Middle Cretaceous Terrestrial Eco- Utah [M.Sc. thesis]: Northern Arizona University, ety of America Bulletin, v. 85, p. 457–464, doi: 10.1130/ systems: New Mexico Museum of Natural History and 262 p. 0016-7606(1974)85<457:POTLTM>2.0.CO;2. Science Bulletin, v. 14, p. 239–248. Fordyce, R.E., 1991, A new look at the fossil vertebrate Hess, H., 1999, Middle Jurassic of northern Switzerland, in Kirkland, J.I., Cifelli, R.L., Britt, B.R., Burge, D.L., record of New Zealand, in Vickers-Rich, P., Monaghan, Hess. H., Ausich, W.I., Brett, C.E., and Simms, M.E., DeCourten , F.L., Eaton, J.G., and Parrish, J.M., 1999, J.M., Baird, R.F., and Williams, C., eds., Vertebrate eds., Fossil Crinoids: Cambridge, Cambridge Univer- Distribution of vertebrate faunas in the Cedar Moun- Palaeon tology of Australasia: Melbourne, Monash sity Press, p. 203–215. tain Formation, east central Utah, in Gillette, D.D., ed., University, p. 1191–1316. Hintze, L.F., 1988, Geologic History of Utah: Provo, Vertebrate Paleontology in Utah: Utah Geological Sur- Frakes, L.A., Jane, E., Francis, J.E., and Syktus, J.I., 1992, Brigham Young University Geology Studies Special vey Miscellaneous Publication 1999–1, p. 201–217. Climate modes of the Phanerozoic: The history of the Publication 7, 202 p. Kowallis, B.J., and Heaton, J.S., 1987, Fission track dating of Earth’s climate over the past 600 million years: New Huntoon, J.E., Dubiel, R.F., Stanesco, J.D., Mickelson, D.L., bentonites and bentonitic mudstones from the Morrison York, Cambridge University Press, 274 p. and Condon, S.M., 2002, Permian-Triassic Deposi- Formation in central Utah: Geology, v. 15, p. 1138–1142, Frey, M., 1987, Very low grade metamorphism of clastic tional Systems, Paleogeography, Paleoclimate, and doi: 10.1130/0091-7613(1987)15<1138:FDOBAB> sedimentary rocks, in Frey, M., ed., Low Temperature Hydrocarbon Resources in Canyonlands and Monu- 2.0.CO;2. Metamorphism: Glasgow, Blackie, p. 9–58. ment Valley, Utah: Boulder, Colorado, Geological So- Kowallis, B.J., Christiansen, E.H., Deino, A.H., Peterson, F., Gaillard, C., Bernier, P., Barale, G., and Bourseau, J.-P., ciety of America, Field Guide 3, 26 p. Turner, C.E., Kunk, M.J., and Obradovich, J.D., 1998, Buffetaut , E., Ezquerra, R., Gall, J.-C., de Broin, de L., Hvoslef, S., Dypvik, H., and Solli, H., 1986, A combined The age of the Morrison Formation: Modern Geology, Renous, S., and Wenz, S., 2003, A giant Upper Juras- sedimentological and organic geochemical study of the v. 22, p. 235–260. sic turtle revealed by its trackways: Lethaia, v. 36, Jurassic/Cretaceous Janusfjellet Formation (Svalbard), Kowallis, B.J., Christiansen, E.H., Deino, A.H., Zhang, p. 315–322. Norway: Organic Geochemistry, v. 10, p. 101–111, C.-G., and Everett, B.H., 2001, The record of middle Galfetti, T., Hochuli, P.A., Brayard, A., Bucher, H., Weissert, doi: 10.1016/0146-6380(86)90013-6. Jurassic volcanism in the Carmel and Temple Cap H., and Vigran, J.O., 2007, Smithian-Spathian bound- Iannuzzi, R., and Souza, P.A., 2005, Floral succession in the Forma tions of southwestern Utah: Geological Society ary event; evidence for global climatic change in the Lower Permian deposits of the Brazilian Paraná Basin: of America Bulletin, v. 113, p. 373–387, doi: 10.1130/ wake of the end-Permian biotic crisis: Geology, v. 35, An up-to-date overview, in Lucas, S.G., and Ziegler, 0016-7606(2001)113<0373:TROMJV>2.0.CO;2. p. 291–294, doi: 10.1130/G23117A.1. K.E., eds., The Nonmarine Permian: New Mexico Mu- Kutzbach, J.E., and Gallimore, R.G., 1989, Pangaean cli- Gand, G., Garric, J., Schneider, J., Sciau, J., and Walter, seum of Natural History and Science Bulletin, v. 30, mates; megamonsoons of the megacontinent: Journal H., 1996, Biocoenoses à méduses du Permien fran- p. 144–149. of Geophysical Research, v. 94, p. 3341–3357, doi: çais (Basin de Saint-Affrique, Massif Central): Geo- Isaacs, C.M., 1989, Field trip guide to the Miocene Mon- 10.1029/JD094iD03p03341. bios, v. 29, p. 379–400, doi: 10.1016/S0016-6995(96) terey Formation, Salinas and Santa Barbara area, Lin, B., Wielicki, B.A., Chambers, L.H., et al., 2002, The 80001-5. California, in Blueford, J., and Isaacs, C., eds., Meso- Iris hypothesis: A negative or positive cloud feed- Gaudant, J., and Quayle, 1988, New paleontological stud- zoic and Cenozoic Siliceous Sediments of California: back?: Journal of Climate, v. 15, p. 3–7, doi: 10.1175/ ies on the Chapelcorner fi sh bed (Upper Eocene, Isle International Geological Congress Field Trip Guide- 1520-0442(2002)015<0003:TIHANO>2.0.CO;2. of Wight): British Museum Natural History Geology book: Washington, D.C., American Geophysical Loope, D.B., Steiner, M.B., Rowe, C.M., and Lancaster, Series Bulletin, v. 44, p. 15–39. Union, p. 21–50. N., 2004, Tropical westerlies over Pangean sand Goldstrand, P.M., Trexler, J.H., Kowallis, B.J., and Eaton, Jenkyns, H.C., 2003, Evidence for rapid climate change seas: Sedimentology, v. 51, p. 315–322, doi: 10.1046/ J.G., 1993, Late Cretaceous to early Tertiary tec- in the Mesozoic-Palaeogene greenhouse world: j.1365-3091.2003.00623.x. tonostratigraphy of southwestern Utah, in Morales, M., Royal Society of London Philosophical Transactions, Lucas, S.G., and Tanner, L.H., 2007, Tetrapod biostra- ed., Aspects of Mesozoic Geology and Paleontology of v. A361, p. 1885–1916. tigraphy and biochronology of the Triassic-Jurassic the Colorado Plateau: Museum of Northern Arizona Jenkyns, H.C., Jones, C.E., Grocke, D.R., Hesselbo, S.P., transition on the southern Colorado Plateau: Palaeo- Bulletin, v. 59, p. 181–188. and Parkinson, D.N., 2002, Chemostratigraphy of geography, Palaeoclimatology, Palaeoecology, v. 244, Gomez, B., Thévenard, F., Fantin, M., and Guisberti, L., the Jurassic System: Application, limitations and im- p. 242–256, doi: 10.1016/j.palaeo.2006.06.030. 2002, Late Cretaceous plants from the bonarelli plications for paleoceanography: Journal of the Geo- Lucas, S.G., Heckert, A.B., Estep, J.W., and Anderson, O., level of the Venetian Alps, northeastern Italy: Cre- logical Society of London, v. 159, p. 351–378, doi: 1997, Stratigraphy of the Upper Triassic Chinle Group, taceous Research, v. 23, p. 671–685, doi: 10.1006/ 10.1144/0016-764901-130. Four Corners region, in Anderson, O.J., Kues, B., and cres.2002.1026. Jennings, D.S., and Hasiotis, S.T., 2006, Paleoenviron mental Lucas, S.G., eds., Mesozoic Geology and Paleontology Gonzalez-Rodriguez, K., Applegate, S.P., and Espinosa- and stratigraphic implications of authigenic clay dis- of the Four Corners Region: New Mexico Geological Arrubarrena, L., 2004, A New World macrosemid tributions in Morrison Formation deposits, Bighorn Society Guidebook, p. 81–108. (Pisces; Neopterygii-Halecostomei) from the Albian Basin, Wyoming, in Foster, J.R., and Lucas, S.G., eds., MacRae, C., 1999, Life Etched in Stone: Fossils of South of Mexico: Journal of Vertebrate Paleontology, v. 24, Paleontology and Geology of the Upper Jurassic Mor- Africa: Johannesburg, Geological Survey of South Af- p. 281–289, doi: 10.1671/1862. rison Formation: New Mexico Museum of Natural His- rica, 305 p. Gradstein, F.M., Ogg, J.G., and Smith, A.G., 2004, A Geo- tory and Science Bulletin, v. 36, p. 25–34. Marbut, C.F., 1935, Atlas of American Agriculture. III. Soils logic Time Scale 2004: Cambridge, Cambridge Uni- Jenny, H.J., 1941, Factors in Soil Formation: New York, of the United States: Washington, D.C., Albuquerque, versity Press, 589 p. McGraw-Hill, 281 p. New Mexico, U.S. Government Printing Offi ce, 99 p. Granger, H.C., Finch, W.I., Bromfi eld, C.S., Duval, J.S., Jiang, D.-Y., Hao, W.-C., Maisch, M.W., Matzke, A.T., and McElwain, J.C., Beerling, D.J., and Woodward, F.I., 1999, Grauch, V.J.S., Green, M.W., Hills, F.A., Peterson, F., Sun, Y.-L., 2005, A basal mixosaurid ichthyosaur from Fossil plants and global warming at the Triassic- Pierson, C.T., Sanford, R.F., Spirakis, C.S., and Wahl, the Middle Triassic of China: Palaeontology, v. 48, Jurassic boundary: Science, v. 285, p. 1386–1390, doi: R.R., 1988, The Colorado Plateau Uranium Province, p. 869–882, doi: 10.1111/j.1475-4983.2005.00481.x. 10.1126/science.285.5432.1386. USA, in Moore, J., ed., Recognition of Uranium Prov- Johnson, A.H., 1976, Palaeomagnetism of the Jurassic McElwain, J.C., Wade-Murphy, J., and Hesselbo, S.P., 2005, inces: Vienna, International Atomic Energy Agency, Navajo Sandstone from southwestern Utah: Geophysi- Changes in carbon dioxide during an oceanic anoxic p. 157–173. cal Journal of the Royal Astronomical Society, v. 44, event linked to intrusion into Gondwana coals: Nature, Grimaldi, D., and Engel, M.S., 2005, Evolution of the In- p. 161–175. v. 435, p. 479–482, doi: 10.1038/nature03618. sects: Cambridge, Cambridge University Press, 755 p. Kasting, J.F., and Catling, D., 2003, Evolution of a hab- McFadden, L.D., and Tinsley, J.C., 1985, Rate and depth of Gustavson, T.C., and Holliday, V.T., 1999, Eolian sedimen- itable planet: Annual Review of Astronomy and Astro- pedogenic-carbonate accumulation in soils; formula- tation and soil development on a semiarid and sub- physics, v. 41, p. 429–463, doi: 10.1146/annurev. tion and testing of a compartment model, in Weide, humid grassland, Tertiary Ogallala and Quaternary astro.41.071601.170049. D.L., ed., Soils and Quaternary Geology of the South-

Blackwater Draw Formations, Texas and New Mexico: Kaufman, A.J., and Xiao, S., 2003, High CO2 levels in the western United States: Geological Society of America Journal of Sedimentary Research, v. 69, p. 622–634. Proterozoic atmosphere estimated from analyses of in- Special Paper 203, p. 23–41. Hagdorn, H., Wang, X.-F., and Wang, C.-S., 2007, Palaeo- dividual microfossils: Nature, v. 425, p. 279–282, doi: Meyer, H.W., 2003, The Fossils of Florissant: Washington, ecology of the pseudoplanktonic Triassic crinoid 10.1038/nature01902. D.C., Smithsonian Books, 258 p.

Geological Society of America Bulletin, September/October 2009 1453 Retallack

Milner, A.R., 1981, On the identity of “Ptyonius bendai” Reeve, S.C., 1975, Paleomagnetic Studies of Sedimentary Scott, K.M., 2005, Cohesion, water vapor, and fl oral topog- (Amphibia) from the Lower Permian of Kost’alov, Rocks of Cambrian and Triassic Age [Ph.D. thesis]: raphy: Signifi cance for the interpretation of the depo- Czechoslovakia: Neues Jahrbuch für Geologie und Dallas, University of Texas, 384 p. sitional mechanisms of the late Paleozoic Halgaito Paläontologie, v. 6, p. 346–352. Retallack, G.J., 1991, Untangling the effects of burial al- Formation, Cutler Group, southeastern Utah, in Lucas, Molina-Garza, R.S., Geissmann, J.W., Lucas, S.G., and Van teration and ancient soil formation: Annual Review of S.G., and Kiegler, K.E., ed., The Nonmarine Permian: der Voo, R., 1996, Palaeomagnetism and magneto- Earth and Planetary Sciences, v. 19, p. 183–206, doi: New Mexico Museum of Natural History and Science stratigraphy of Triassic strata in the Sangre de Cristo 10.1146/annurev.ea.19.050191.001151. Bulletin, v. 30, p. 296–299. Mountains and Tucumcari Basin, New Mexico, USA: Retallack, G.J., 2001, A 300-million-year record of atmo- Sheldon, N.D., 2006a, Abrupt chemical weathering increase Geophysical Journal International, v. 124, p. 935–953, spheric carbon dioxide from fossil plant cuticles: Na- across the Permian-Triassic boundary: Palaeogeog- doi: 10.1111/j.1365-246X.1996.tb05646.x. ture, v. 411, p. 287–290, doi: 10.1038/35077041. raphy, Palaeoclimatology, Palaeoecology, v. 231, Montañez, I.P., Tabor, N.J., Niemeier, D., DiMichele, W.A., Retallack, G.J., 2002, Carbon dioxide and climate over the p. 315–321, doi: 10.1016/j.palaeo.2005.09.001. Frank, T.D., Fielding, C.R., Isbell, J.L., Birgenheier, past 300 million years: Royal Society of London Philo- Sheldon, N.D., 2006b, Precambrian paleosols and atmo-

L.P., and Rygel, M.C., 2007, CO2-forced climate and sophical Transactions, v. A360, p. 659–674. spheric CO2 levels: Precambrian Research, v. 147, vegetation instability during late Paleozoic deglaciation: Retallack, G.J., 2004, Soils and global change in the car- p. 148–155, doi: 10.1016/j.precamres.2006.02.004. Science, v. 315, p. 87–91, doi: 10.1126/science.1134207. bon cycle over geological time, in Holland, H.D., and Sheldon, N.D., and Retallack, G.J., 2001, An equation Mory, A.J., and Iasky, R.P., 1996, Stratigraphy and Struc- Turekian, K.K., eds., Treatise on Geochemistry, Vol- for compaction of paleosols due to burial: Geology, ture of the Northern Perth Basin: Geological Survey of ume 5: Oxford, Pergamon Press, p. 581–605. v. 29, p. 247–250, doi: 10.1130/0091-7613(2001) Western Australia, v. 46, 101 p. Retallack, G.J., 2005a, Pedogenic carbonate proxies for 029<0247:EFCOPD>2.0.CO;2. Muehlberger, W.R., Adams, G.E., Longood, T.E., and amount and seasonality of precipitation in paleosols: Sheldon, N.D., Retallack, G.J., and Tanaka, S., 2002, St. John, B.E., 1960, Stratigraphy of the Chama Quad- Geology, v. 33, p. 333–336, doi: 10.1130/G21263.1. Geochemical climofunctions from North American rangle, northern Rio Arriba County, New Mexico: Retallack, G.J., 2005b, Permian greenhouse crises, in Lucas, soils and application to paleosols across the Eocene- Albuquerque, New Mexico, 1960 Guidebook, New S.G., and Ziegler, K.E., ed., The Nonmarine Permian: Oligocene boundary in Oregon: The Journal of Geol- Mexico Geological Society, p. 93–102. New Mexico Museum of Natural History and Science ogy, v. 110, p. 687–696, doi: 10.1086/342865. Nathorst, A.G., 1897, Zur fossilen Flora der Polarländer: Bulletin, v. 30, p. 256–269. Smiley, C.J., ed., 1985, Late Cenozoic History of the Pacifi c Konigla Svenska Vetensk-Akademie Handlingar, v. 241, Retallack, G.J., 2007, Cenozoic paleoclimate on land in Northwest; Interdisciplinary Studies on the Clarkia p. 1–77. North America: The Journal of Geology, v. 115, Fossil Beds of Northern Idaho: San Francisco, Pacifi c Nordt, L., Atchley, S., and Dworkin, S., 2003, Terres- p. 271–294, doi: 10.1086/512753. Division American Association for the Advancement trial evidence for two greenhouse events in the latest Retallack, G.J., Metzger, C.A., Greaver, T., Jahren, A.H., of Science, 417 p. Cretaceous: GSA Today, v. 13, no. 12, p. 4–9, doi: Sheldon, N.D., and Smith, R.M.H., 2006, Middle-Late Smit, J., 1999, The global stratigraphy of the Cretaceous- 10.1130/1052-5173(2003)013<4:TEFTGE>2.0.CO;2. Permian mass extinction on land: Geological Soci- Tertiary boundary ejecta: Annual Review of Earth and Olsen, P.E., and Johanessen, A.K., 1994, Fossil guide to Late ety of America Bulletin, v. 118, p. 1398–1411, doi: Planetary Sciences, v. 27, p. 75–115, doi: 10.1146/ Triassic sites in Virginia and North Carolina, in Fraser, 10.1130/B26011.1. annurev.earth.27.1.75. N.C., and Sues, H.-D., eds., In the Shadow of Dino- Ribeiro, J., 1921, The Geology of Worli Hill: Bombay Natu- Spinar, Z.V., 1972, Tertiary Frogs from Central Europe: saurs: Early Mesozoic Tetrapods: Cambridge, Cam- ral History Society Journal, v. 27, p. 582–595. Prague, Academia, 286 p. bridge University Press, p. 409–430. Rich, T.V., and Vickers-Rich, P., 2000, Dinosaurs of Dark- Sprinkel, D.A., Weiss, M.P., Fleming, R.W., and Wanders,

Pagani, M., 2002, The alkenone-CO2 proxy and ancient ness: Bloomington, Indiana University Press, 222 p. G.C., 1999, Redefi ning the Lower Cretaceous Stratig- atmospheric carbon dioxide: Royal Society of London Roberts, E.M., Deino, A.L., and Chan, M.A., 2005, 40Ar/39Ar raphy within the Central Utah Foreland Basin: Utah Philosophical Transactions, v. 360, p. 609–632. age of the Kaiparowits Formation, southern Utah, and Geological Survey Special Study, v. 97, 21 p. Pearson, P.N., and Palmer, M.R., 1999, Middle Eocene sea- correlation of contemporaneous Campanian strata Steiner, M.B., 1978, Magnetic polarity stratigraphy water pH and atmospheric carbon dioxide concentra- and vertebrate faunas along the margin of the Western during the Middle Jurassic as recorded in the tions: Science, v. 284, p. 1824–1826, doi: 10.1126/ Interior Basin: Cretaceous Research, v. 26, p. 307–318, Summerville and Curtis Formations: Earth and science.284.5421.1824. doi: 10.1016/j.cretres.2005.01.002. Planetary Science Letters, v. 38, p. 331–345, doi: Peters, S.E., 2006, Genus extinction, origination, and dura- Ross, C.A., and Ross, J.P., 1995, Permian sequence stratig- 10.1016/0012-821X(78)90107-3. tion of sedimentary hiatuses: Paleobiology, v. 32, raphy, in Scholle, P.A., Peryt, T., and Ulmer-Scholle, Steiner, M.B., and Helsley, C.E., 1974, Magnetic po- p. 387–407, doi: 10.1666/05081.1. D.S., eds., The Permian of Northern Pangea: Volume I. larity sequence of Upper Triassic Kayenta For- Piper, D.Z., and Perkins, R.B., 2004, A modern vs. Paleogeography, Paleoclimates, Stratigraphy: Berlin, mation: Geology, v. 2, p. 191–194, doi: 10.1130/ Permian black shale; the hydrography, primary pro- Springer, p. 98–123. 0091-7613(1974)2<191:MPSOTU>2.0.CO;2. ductivity, and water-column chemistry of deposition: Rothman, D.H., 2002, Atmospheric carbon dioxide levels for Swinehart, J.B., Sonders, U.C., DeGraw, H.M., and Diffendal , Chemical Geology, v. 206, p. 177–197, doi: 10.1016/ the last 500 million years: Proceedings of the National R.F., 1985, Cenozoic paleogeography of Nebraska, in j.chemgeo.2003.12.006. Academy of Sciences of the USA, v. 99, p. 4167–4171. Flores, R.M., and Kaplan, S.S., eds., Cenozoic Paleo- Poyato-Ariza, F.J., and Wenz, S., 2005, Acroystax telmachi- Rowe, C.M., Loope, D.B., Oglesby, R.J., Van der Voo, R., and geography of the West-Central United States: Denver, ton, gen. et sp. nov., a new pycnodontid fi sh in the Broadwater, C.E., 2007, Inconsistencies between Pan- Rocky Mountain Section Society of Economic Paleon- Lebanese Late Cretaceous of Haqel and en Nammoura: gean reconstructions and basic climate controls: Science, tologists and Mineralogists, p. 209–229. Journal of Vertebrate Paleontology, v. 25, p. 27–45, v. 318, p. 1284–1286, doi: 10.1126/science.1146639. Tabor, N.J., and Yapp, C.J., 2005, Coexisting goethite and

doi: 10.1671/0272-4634(2005)025[0027:ATGESN] Royer, D.L., 2006, CO2-forced climate thresholds during gibbsite from a high-paleolatitude (55°N) late Paleo- 2.0.CO;2. the Phanerozoic: Geochimica et Cosmochimica Acta, cene laterite; concentration and 13C/12C ratios of

Prager, M.H., and Hoenig, J.M., 1989, Superposed epoch v. 70, p. 5665–5675, doi: 10.1016/j.gca.2005.11.031. occluded CO2 and associated organic matter: Geochi- analysis: A randomization test of environmental ef- Royer, D.L., Berner, R.A., and Beerling, D.J., 2001, mica et Cosmochimica Acta, v. 69, p. 5495–5510, doi:

fects on recruitment with application to chub mack- Phanerozoic atmospheric CO2 change: Evaluating 10.1016/j.gca.2005.07.017. erel: Transactions of the American Fisheries Society, geochemical and paleobiological approaches: Earth- Talling, P.J., Burbank, D.W., Lawton, T.F., Hobbs, R.S., and v. 118, p. 608–618, doi: 10.1577/1548-8659(1989)118 Science Reviews, v. 54, p. 349–392, doi: 10.1016/ Lund, S.P., 1994, Magnetostratigraphic chronology of <0608:SEAART>2.3.CO;2. S0012-8252(00)00042-8. Cretaceous-to-Eocene thrust belt evolution, central Utah, Prochnow, S.J., Nordt, L.C., Atchley, S.C., and Hudec, M.R., Royer, D.L., Hickey, L.J., and Wing, S.L., 2003, Ecologi- U.S.A.: The Journal of Geology, v. 102, p. 181–196. 2006, Multiproxy paleosol evidence for Middle and cal conservatism in the ‘living fossil’ Ginkgo: Paleo- Tang, C.M., 2002, Osteno: Jurassic preservation to the cellu- Late Triassic climate trends in eastern Utah: Palaeo- biology, v. 29, p. 84–104, doi: 10.1666/0094-8373 lar level, in Bottjer, D.J., Etter, W., Hagadorn, J.W., geography, Palaeoclimatology, Palaeoecology, v. 232, (2003)029<0084:ECITLF>2.0.CO;2. and Tang, C.M., eds., Exceptional Fossil Preservation: p. 53–72, doi: 10.1016/j.palaeo.2005.08.011. Royer, D.L., Berner, R.A., Montañez, I., and Beerling, D.J., A Unique View of the Evolution of Marine Life: New

Prothero, D.R., 1996, Magnetic stratigraphy and biostratig- 2004, CO2 as a primary driver of Phanerozoic climate: York, Columbia University Press, p. 251–264. raphy of the Middle Eocene Uinta Formation, Uinta GSA Today, v. 14, p. 4–10, doi: 10.1130/1052-5173 Tanner, L.H., Smith, D.L., and Allan, A., 2007, Stomatal

Basin, Utah, in Prothero, D.R., ed., The Terrestrial (2004)014<4:CAAPDO>2.0.CO;2. response of swordfern to volcanogenic CO2 and SO2 Eocene-Oligocene Transition in North America: New Royer, D.L., Berner, R.A., and Park, J., 2007, Climate sensi- from Kilauea Volcano: Geophysical Research Letters,

York, Cambridge University Press, p. 3–24. tivity constrained by CO2 concentrations over the past v. 34, L15807, doi: 10.1029/2007 GL030320. Radnitsyn, A.P., Jarzembowski, E.A., and Ross, A.J., 1998, 420 million years: Nature, v. 446, p. 530–532, doi: Taverne, L., 2004, Ostéologie de Pentanogmius evolutus Wasps (Insecta: Vespida=Hymenoptera) from the 10.1038/nature05699. (Cope, 1877) n. comb. (Teleostei, Tselfatiformes), du Purbeck and Wealden (lower Cretaceous) of south- Ruffner, J.A., 1978, Climates of the States: Detroit, Gale Re- Crétacé supérieur marine des États-Unis: Remarques ern England and their biostratigraphical signifi cance: search, 2 volumes, 1052 p. sur la systématique du genre Pentanogmius Taverne, Cretaceous Research, v. 19, p. 329–391, doi: 10.1006/ Schaal, S., and Ziegler, W., eds., 1992, Messel: An Insight 2000: Geodiversitas, v. 26, p. 89–113. cres.1997.0114. into the History of Life and of the Earth: Oxford, Tintori, A., 1996, The fi eld excursion in northern Italy, in Rasbury, E.T., Hanson, G.N., Meyers, W.J., Holt, W.E., Claren don Press, 322 p. Arratia, G., and Viohl, G., eds., Mesozoic Fishes: Sys- Goldstein, R.H., and Saller, A., H., 1998, U-Pb dates Schaeffer, B., and Mangus, M., 1976, An Early Triassic fi sh tematics and Paleoecology: Munich, Pfeil, p. 567–575. of paleosols: Constraints on late Paleozoic cycle dura- assemblage from British Columbia: American Mu- Tomida, Y., and Butler, R.F., 1980, Dragonian mammals and tions and boundary ages: Geology, v. 26, p. 403–406. seum of Natural History Bulletin, v. 156, p. 515–564. Paleocene magnetic polarity stratigraphy, North Horn

1454 Geological Society of America Bulletin, September/October 2009 Past greenhouse crises

Formation, central Utah: American Journal of Science, from the Miocene of Europe: Geobios, v. 35, p. 745– sols: Implications for paleoecological interpretations v. 280, p. 787–811. 757, doi: 10.1016/S0016-6995(02)00086-4. of paleosols: Palaeogeography, Palaeoclimatology, Tozer, E.T., 1967, A Standard for Triassic Time: Geological Westermann, G.E.G., Hudson, N., and Grant-Mackie, J.A., Palaeoecology, v. 251, p. 437–448, doi: 10.1016/ Survey of Canada Bulletin, v. 156, 103 p. 2000, Bajocian (Middle Jurassic): Ammonitina of New j.palaeo.2007.04.009. Turner, C.E., and Peterson, F., 1999, Biostratigraphy of Zealand: Royal Society of New Zealand Journal, v. 43, Zawiskie, J., Chapman, D., and Alley, R., 1982, Depositional dino saurs in the Upper Jurassic Morrison Formation p. 33–57. history of the Paleocene-Eocene Colton Formation, of the Western Interior, U.S.A., in Gillette, D.D., ed., Wignall, P.B., 1994, Black Shales: Oxford, Oxford Univer- north-central Utah, in Nielson, D.L., ed., Overthrust Vertebrate Paleontology in Utah: Utah Geological Sur- sity Press, 127 p. Belt of Utah: Utah Geological Association Publication vey Miscellaneous Publication 1999–1, p. 77–114. Witzmann, F., and Pfritzschner, H.D., 2003, Larval ontogeny 10, p. 273–284. Vakhrameev, V.A., 1991, Jurassic and Cretaceous Floras and of Micromelerpeton credneri (Temnospondyli: Dis- Zhou, Z.-D., Barrett, P.M., and Hilton, J., 2003, An excep- Climates of the Earth: Cambridge, Cambridge Univer- soro phoidea): Journal of Vertebrate Paleontology, tionally preserved Lower Cretaceous ecosystem: Na- sity Press, 318 p. v. 23, p. 750–768, doi: 10.1671/3. ture, v. 421, p. 807–814, doi: 10.1038/nature01420. Veizer, J., Godderis, Y., and François, L.M., 2000, Evidence Wynn, J.G., 2003, Towards a physically based model

for decoupling of atmospheric CO2 and global climate of CO2-induced stomatal frequency response: The MANUSCRIPT RECEIVED 11 OCTOBER 2007 during the Phanerozoic eon: Nature, v. 408, p. 698– New Phytologist, v. 157, p. 391–398, doi: 10.1046/ REVISED MANUSCRIPT RECEIVED 23 SEPTEMBER 2008 701, doi: 10.1038/35047044. j.1469-8137.2003.00715.x. MANUSCRIPT ACCEPTED 6 OCTOBER 2008 Wegierek, P., and Peñalver, E., 2002, Fossil representatives Wynn, J.G., 2007, Carbon isotope fractionation during of the family Greenideidae (Hemiptera, Aphidoidea) decomposition of organic matter in soils and paleo- Printed in the USA

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