Permian Stage Research Articles

Rise and diversification of chondrichthyans in the Paleozoic

AbstractThe Paleozoic represents a key time interval in the origins and early diversification of chondrichthyans (cartilaginous fishes), but their diversity and macroevolution are largely obscured by heterogenous spatial and temporal sampling. The predominantly cartilaginous skeletons of chondrichthyans pose an additional limitation on their preservation potential and hence on the quality of their fossil record. Here, we use a newly compiled genus-level dataset and the application of sampling standardization methods to analyze global total-chondrichthyan diversity dynamics through time from their first appearance in the Ordovician through to the end of the Permian. Subsampled estimates of chondrichthyan genus richness were initially low in the Ordovician and Silurian but increased substantially in the Early Devonian. Richness reached its maximum in the middle Carboniferous before dropping across the Carboniferous/Permian boundary and gradually decreasing throughout the Permian. Sampling is higher in both the Devonian and Carboniferous compared with the Silurian and most of the Permian stages. Shark-like scales from the Ordovician are too limited to allow for some of the subsampling techniques. Our results detect two Paleozoic radiations in chondrichthyan diversity: the first in the earliest Devonian, led by acanthodians (stem-group chondrichthyans), which then decline rapidly by the Late Devonian, and the second in the earliest Carboniferous, led by holocephalans, which increase greatly in richness across the Devonian/Carboniferous boundary. Dispersal of chondrichthyans, specifically holocephalans, into deeper-water environments may reflect a niche expansion following the faunal displacement in the aftermath of the Hangenberg extinction event at the end of the Devonian.

Orogenic Volcanism in Eastern Kazakhstan: Composition, Age, and Geodynamic Position

Studies of volcanic rocks in orogenic troughs of Eastern Kazakhstan were carried out. The troughs were formed at late-orogenic stages of evolution of Hercynian Altai collision system. Volcanic rocks are represented by basalts, andesites, dacites and rhyolites. Based on geochemical and isotopic data, the basalts and andesites derived from mafic magmas that formed as a result of partial melting of garnet peridotites in the upper mantle under the orogen. U–Pb zircon data prove two volcanic stages: more-scaled Middle Carboniferous (~311 Ma) and less-scaled Early Permian (297–290 Ma). Basalts and andesites in lower parts of the orogenic troughs and independent dacite-rhyolite structures were formed at the Middle Carboniferous stage. Parental mafic magmas were formed as a result of partial melting of mantle substrates in local transtensional zones along large shear faults. The formation of dacites and rhyolites could have been caused by partial melting of crustal substrates under effect of mafic magmas. Transtensional movements in the lithosphere of orogenic belts may indicate the beginning of collapse of orogens. A smaller volume of basalts and andesites formed at the Early Permian stage. Geochemical data prove the independent episode of partial melting in upper mantle. Synchronous basalts and andesites also appeared at wide territory in Tian Shan, Central Kazakhstan, and Central and Southern Mongolia. Early Permian volcanism indicates general extension of the lithosphere at the postorogenic stages. Large-scaled Early Permian mafic and granitoid magmatism in Central Asia has been interpreted in recent years as the Tarim Large Igneous Province caused by Tarim mantle plume activity. Thus, the extension of the lithosphere and associated volcanism in the Early Permian can be an indicator of the onset of the plume–lithosphere interaction process.

The Permian timescale: an introduction

Abstract The Permian timescale has developed over about two centuries of research to the current chronostratigraphic scale advocated by the Subcommission on Permian Stratigraphy of three series and nine stages: Cisuralian (lower Permian) – Asselian, Sakmarian, Artinskian, Kungurian; Guadalupian (middle Permian) – Roadian, Wordian, Capitanian; and Lopingian (upper Permian) – Wuchiapingian and Changhsingian. The boundaries of the Permian System are defined by global stratotype sections and points (GSSPs) and the numerical ages of those boundaries appear to be determined with a precision better than 1‰. Nevertheless, much work remains to be done to refine the Permian timescale. Precise numerical age control within the Permian is very uneven and a global polarity timescale for the Permian is far from established. Chronostratigraphic definitions of three of the nine Permian stages remain unfinished and various issues of marine biostratigraphy are still unresolved. In the non-marine Permian realm, much progress has been made in correlation, especially using palynomorphs, megafossil plants, conchostracans and both the footprints and bones of tetrapods (amphibians and reptiles), but many problems of correlation remain, especially the cross-correlation of non-marine and marine chronologies. The further development of a Permian chronostratigraphic scale faces various problems, including those of stability and priority of nomenclature and concepts, disagreements over changing taxonomy, ammonoid v. fusulinid v. conodont biostratigraphy, differences in the perceived significance of biotic events for chronostratigraphic classification and correlation problems between provinces. Future research on the Permian timescale should focus on GSSP selection for the remaining undefined stage bases, the definition and characterization of substages, and further development and integration of the Permian chronostratigraphic scale with radioisotopic, magnetostratigraphic and chemostratigraphic tools for calibration and correlation.

Permian conodont biostratigraphy

Abstract Forty Permian conodont biozones are summarized and 35 additional regional zones are correlated. The Lower Permian is largely zoned on the basis of partial range lineage interval zones of species of Streptognathodus , Sweetognathus , Neostreptognathodus and Mesogondolella . The Middle and Upper Permian are zoned, respectively, on the basis of partial range lineage interval zones of species of Jinogondolella and Clarkina . The ranges of all key taxa to develop this zonation are depicted in relation to the geochronological ages of Permian stages. The lowest Permian succession has been astronomically tuned with 400 kyr cyclothems linked to interpolated ages in the Uralian succession.

The Permian chronostratigraphic scale: history, status and prospectus

Abstract In 1841, Murchison coined the term Permian for strata in the Russian Urals. Recognition of the Permian outside of Russia and central Europe soon followed, but it took about a century for the Permian to be accepted globally as a distinct geological system. The work of the Subcommission on Permian Stratigraphy began in the 1970s and resulted in current recognition of nine Permian stages in three series: the Cisuralian (lower Permian) – Asselian, Sakmarian, Artinskian and Kungurian; the Guadalupian (middle Permian) – Roadian, Wordian and Capitanian; and the Lopingian (upper Permian) – Wuchiapingian and Changhsingian. The 1990s saw the rise of Permian conodont biostratigraphy, so that all Permian Global Stratigraphic Sections and Points (GSSPs) use conodont evolutionary events as the primary signal for correlation. Issues in the development of a Permian chronostratigraphic scale include those of stability and priority of nomenclature and concepts, disagreements over changing taxonomy, ammonoid v. fusulinid v. conodont biostratigraphy, differences in the perceived significance of biotic events for chronostratigraphic classification, and correlation problems between provinces. Further development of the Permian chronostratigraphic scale should focus on GSSP selection for the remaining, undefined stage bases, definition and characterization of substages, and further integration of the Permian chronostratigraphic scale with radioisotopic, magnetostratigraphic and chemostratigraphic tools for calibration and correlation.

Permian ammonoid biostratigraphy

Abstract A brief historical review of ammonoid-based Permian biostratigraphy is performed. Changes in ammonoid associations are shown for each of nine Permian stages. The major correlation problems were discussed. A renewed ammonoid zonal scale is proposed.

Early Permian stage of formation of gold-ore deposits of northeastern Transbaikalia: Isotope-geochronological (Rb-Sr and 39Ar-40Ar) data for the Uryakh ore field

This work presents the first results of geochronological study of metasomatic rocks accompanying gold-bearing quartz veins of the Uryakh ore field (UOF). Based on the Rb-Sr and 39Ar-40Ar geochronological data, it is shown that hydrothermal metasomatic processes in the ore field occurred about 280 Ma ago (Early Permian) and they are correlated with the terminal phases of formation of the Angara-Vitim batholith.

The Gondwana Orogeny in northern North Patagonian Massif: Evidences from the Caita Có granite, La Seña and Pangaré mylonites, Argentina

Structural analyses in the northern part of the North Patagonia Massif, in the foliated Caita Có granite and in La Seña and Pangaré mylonites, indicate that the pluton was intruded as a sheet-like body into an opening pull-apart structure during the Gondwana Orogeny. Geochronological studies in the massif indicate a first, lower to middle Permian stage of regional deformation, related to movements during indentation tectonics, with emplacement of foliated granites in the western and central areas of the North Patagonian Massif. Between the upper Permian and lower Triassic, evidence indicates emplacement of undeformed granitic bodies in the central part of the North Patagonian Massif. A second pulse of deformation between the middle and upper Triassic is related to the emplacement of the Caita Có granite, the development of mylonitic belts, and the opening of the Los Menucos Basin. During this pulse of deformation, compression direction was from the eastern quadrant.

The diversity of the Permian phytoplankton

The Paleozoic fossil record of organic-walled microphytoplankton is represented by the acritarchs, organic-walled microfossils (OWMs) considered mostly as the resting cysts of phytoplanktonic organisms, although the biological affinities of the acritarchs are, by definition, unknown. Acritarchs appear in the Precambrian and reach their highest diversity in the Lower and Middle Paleozoic (Cambrian to Devonian). After a drastic diversity drop in the Devonian, they are considered to be of very low diversity in the Upper Paleozoic (Carboniferous to Permian), where some authors claim the presence of a ‘phytoplankton blackout’ due to nutrient depletion in the oceans. Here we present a synthesis of the Permian fossil record of acritarchs. The revision shows that Permian acritarch descriptions have largely been neglected, compared to other palynomorph groups, such as spores and pollen grains. While larger organic-walled cysts, as known from the Lower and Middle Paleozoic, are usually absent, many smaller acritarchs are commonly found in Permian palynological assemblages. In addition, several OWMs interpreted as fungal spores have been described, but also possible green algae, including chlorophycean, prasinophycean or zygnematophyceaen algae. During most of the Permian stages, OWMs show genus richness of about 20 to 30 genera. Some genera, such as Micrhystridium and Veryhachium, have been reported in over 40 publications. Nevertheless, many Permian acritarchs still need to be documented in detail, and additional systematical studies, in particular of the very small taxa, are needed to fully understand the diversity and significance of Permian phytoplankton.

Thermal maturation and exhumation of a middle orogenic crust in the Livradois area (French Massif Central)

AbstractUpper Carboniferous heating and melting of the middle orogenic crust associated with the emplacement of syntectonic granitoids are documented in the Upper Gneissic Unit of the Livradois area (central part of the French Massif Central). Crustal melting post-dates peak metamorphism conditions (800-625°C, 10-8 kb) dated at 360 ± 4 Ma (U-Th-Pb on monazite). The P-T evolution of the metamorphic series indicates that Barrovian metamorphism was followed by a decompression (from 10 ± 1 kbar to 6 ± 1 kbar) associated with either a decrease in temperature in the southern part of the series or with an increase in temperature (of about 150°C) in the northern part of the series. This evolution records the first step of the exhumation of the series coeval with granitoids intrusion, of which the emplacements were dated at 315 ± 4 and 311 ± 18 Ma (U-Pb on zircon). The final stage of the exhumation is associated with an isobaric cooling of the whole series. Similarity of 40Ar/39Ar ages for biotite in the paragneisses (307-300 Ma) and K-feldspar in the granitoids (306-300 Ma) document rapid cooling for this stage. Moreover dextral reverse mylonites, at the border and the northern part of the metamorphic series indicate north-south compression coeval with the unroofing of the series. Youngest 40Ar-39Ar ages on K-feldspar (274.6 ± 5 Ma) combined with normal shearing in mylonites limiting the Carboniferous Brassac-les-Mines basin document the late Carboniferous-early Permian stage of extension coeval with the upwelling of the Velay granitic dome.

Palaeobiogeography and palaeogeographical implications of Permian marine bivalve faunas in Northeast Asia (Kolyma–Omolon and Verkhoyansk–Okhotsk regions, northeastern Russia)

The paper considers the biogeography and palaeogeographic implications of the Permian marine bivalve faunas of Northeast Asia, with a focus on the dynamic relationships between biotic similarities and palaeogeographic distance through an interval of ca. 50 million years. A stage-by-stage time series analysis of the biotic similarities between two previously recognized biochores in Northeast Asia, the Kolyma–Omolon and Verkhoyan–Okhotsk provinces, has been carried out using both the Jaccard and Dice similarity indices based on the spatio-temporal distributions of 355 Permian marine bivalve species in Northeast Asia. The outcome of this analysis, combined with other empirical data and previously published tectonic, sedimentological and palaeontological information, suggests that (1) the bivalve faunas from these two provinces were distinctive from one another as two separate biochores throughout all but the earliest (Asselian) Permian stages and (2) the biotic similarities between the Verkhoyan–Okhotsk and Kolyma–Omolon provinces remained consistently low since Sakmarian, all falling well below the minimum threshold of the Jaccard index of 0.42 required for distinguishing marine biotic provinces. We interpret these below-threshold Jaccard biotic similarities as an indication of significant palaeogeographic separation between the Verkhoyan-Okhotsk and Kolyma–Omolon provinces, which is in turn considered to indicate rifting and sea-floor spreading of the Omolon microcontinent and associated terranes and island arcs away from the North Asian craton, at least from the Sakmarian to the beginning of the Late Permian. Palaeo-distance separation appears to be the primary and most significant biogeographic determinant in accounting for the differences in the spatial distribution of most Permian bivalve species in Northeast Asia. Several other variables also appear to have played a significant role, including regional climate conditions, ocean currents and merged island chains as geographic barriers. In particular, the relatively high biotic similarity between the Verkhoyan–Okhotsk and Kolyma–Omolon provinces during the Late Wuchiapingian and Changhsingian may have been related to the shallowing of the deep-water basins (Oimyakon, Ayan-Yuryakh, Balygychan and Sugoi basins) that had previously separated the two provinces and the flooding (submergence) of the Okhotsk–Taigonos volcanic arc system, thus allowing the invasion of lower latitude warm-water Palaeotethyan and even Gondwanan species into Northeast Asia.

The age of the carboniferous‐Permian Converrucosisporites confluens Oppel biozone: New data from the Ganigobis shale member (DWYKA group) of Namibia

The establishment of the Converrucosisporites confluens Oppel Zone in the Canning Basin of Australia in cored intervals from the Calytrix No. 1 Borehole was considered to be an advance in Gondwana Carboniferous‐Permian palynostratigraphy. This was because the zone is associated with a marine fauna that suggests a correlation with the standard Russian Early Permian stages. Moreover the index species has a wide occurrence in Gondwana outside Australia, for example Antarctica, Argentina, Brazil, India, Oman, Saudi Arabia, and Uruguay. The zone was originally considered middle to late Asselian in age, but this was later revised to latest Asselian to Early Sakmarian. Converrucosisporites confluens is reported here from the Ganigobis Shale Member of Namibia in a well‐preserved and diverse assemblage including four of the fourteen specified accessory taxa for the Converrucosisporites confluens Oppel Zone. Ash layer IIb of the Ganigobis Shale Member is radiometrically dated as 302.0 ±3.0 Ma (i.e. Pennsylvanian; Gzhelian or Kasimovian) thus the Converrucosisporites confluens Oppel Zone may range earlier than previously thought. Preliminary study of the range top of Converrucosisporites confluens in Argentina and Uruguay suggests that it ranges younger there than in Western Australia with the possibility that the Converrucosisporites confluens Oppel Zone may also be younger than previously thought.

Manifestations of the Late Carboniferous and Early Permian stages of formation of nappe-fold structures in the southern framework of the Siberian platform (East Sayany, South Siberia)

The geological structure of the Tunka Goltsy (the Tunka Range) of the East Sayany is characterized by a complex nappefold structure, composed mainly of Paleozoic terrigenous and carbonate rocks and their metamorphosed analogues (1-3). It is generally rec� ognized that the nappefold structure of the East Sa� yany, including its southeastern segment, regarded as the Tunka terrain (3) or Ilchirskaya zone (4), formed in the Ordovician as a result of collision between the Tuva-Mongolian microcontinent and the Siberian continent. As referred to in (5), the Ordovician-Mid� dle Paleozoic deformations over the entire vast terri� tory of Central Asia, from the Olkhon zone of the Pribaikalie to the North Kazakhstan, were manifested as a result of the closing of the oceanic basin and the subsequent collision between the Kazakhstan- Baikalian complex continent (including the Tuva- Mongolian microcontinent) and the Siberian conti� nent. In the Ordovician the Olkhon nappeoverthrust zone was formed along the southeastern framework of the Siberian Craton. In addition, the metamorphism was manifested over the entire vast territory of the East Sayany that could probably be connected with nappe formation. In the Late Ordovician-Silurian, the oblique slipthrust structures, magmatism, and meta� morphism were manifested in the Sangilen highlands and Tuva. Later, the deformations continued. In the Late Devonian-Early Carboniferous, the dextral strikeslip fault Charysh-Terektinskaya zone was formed; in the Late Carboniferous, the Kurayskaya and Kuznetsko-Teletsko-Bashkaus sinistral strike� slip shear zones were formed. In the Late Carboniferous-Permian, the collision between the East European, Kazakhstan-Baikalian, and Siberian continents took place (5, 6). In East Kazakhstan, the sinistral strikeslip movements took place in the band of more than 400 km width along the Chara ophiolite zone and the Irtysh and Northeastern shear zones. The age of deformation rejuvenates regu� larly to the east towards the internal part of the Sibe� rian continent; the movement amplitude along shears decreases in the same direction from several thousand to a hundred kilometers. In the late Palaeozoic in the Tunka Goltsy and the adjacent regions, a number of geological events of Late Carboniferous and Early Permian age are distin�

THE AGE OF THE CARBONIFEROUS-PERMIAN CONVERRUCOSISPORITES CONFLUENS OPPEL BIOZONE: NEW DATA FROM THE GANIGOBIS SHALE MEMBER (DWYKA GROUP) OF NAMIBIA

Abstract The establishment of the Converrucosisporites confluens Oppel Zone in the Canning Basin of Australia in cored intervals from the Calytrix No. 1 Borehole was considered to be an advance in Gondwana Carboniferous—Permian palynostratigraphy. This was because the zone is associated with a marine fauna that suggests a correlation with the standard Russian Early Permian stages. Moreover the index species has a wide occurrence in Gondwana outside Australia, for example Antarctica, Argentina, Brazil, India, Oman, Saudi Arabia, and Uruguay. The zone was originally considered middle to late Asselian in age, but this was later revised to latest Asselian to Early Sakmarian. Converrucosisporites confluens is reported here from the Ganigobis Shale Member of Namibia in a well-preserved and diverse assemblage including four of the fourteen specified accessory taxa for the Converrucosisporites confluens Oppel Zone. Ash layer IIb of the Ganigobis Shale Member is radiometrically dated as 302.0 ±3.0 Ma (i.e. Pennsyl...

High-precision U–Pb zircon age constraints on the Carboniferous–Permian boundary in the southern Urals stratotype

Volcanic-ash beds within fossiliferous strata of the southern Uralian foredeep of Russia have been dated by the high-precision ID-TIMS U–Pb zircon method, to constrain the age of the Carboniferous–Permian transition. The stratigraphic section exposed at the Usolka locality, an auxiliary stratotype for the Carboniferous–Permian boundary, contains a detailed multi-taxa biostratigraphy with a well-resolved boundary succession tied to the Global Stratotype Section and Point (GSSP) at Aidaralash Creek (Kazakhstan). Four tuffs bracketing the Carboniferous–Permian transition in the Usolka section closely constrain the age of the boundary to 298.90 + 0.31/− 0.15 Ma (2 σ), including both analytical and stratigraphic uncertainty. These data substantially improve the calibration of the geologic time scale in the Late Paleozoic, and presage the radiometric age resolution possible for the late Carboniferous and early Permian stages through continued analysis of ash beds in the southern Urals stratotypes. By stabilizing the numeric age for the base of the Permian, these data also provide an important link between the timing of Permo-Carboniferous glaciation in Gondwana and its far-field climatic and sedimentological consequences in Euramerica.

Reworking of fusulinids and calcisphaerids in the Lercara Formation (Sicily, Italy); geological implications

Different fusulinids have been identified in the Lercara Formation (Sicily). They are: Reichelina sp., Schubertella paramelonica, Toriyamaia (?) sp., Neofusulinella lantenoisi, Yangchienia compressa, Rauserella staffi, Darvasites contractus, Chalaroschwagerina ( Taiyuanella?) aff. davalensis, Levenella aff. evoluta, Pamirina darvasica, and Neoschwagerina ex gr. craticulifera. Small Permian foraminifers, as well as the calcispherid Asterosphaera pulchra also exist. The microfossils indicate reworking of different Permian stages, at different periods of time, and possibly also of the Mississippian (Early Carboniferous). All these resediments have been deposited within the Lercara Formation, a series definitely belonging to the Triassic period. Therefore, due to this reworking, Sicily appears as a controversial area for establishing biostratigraphic and palaeobiogeographic correlations in the Permian period. To cite this article: L. Carcione et al., C.R.Palevol 3 (2004).

Simulated warm polar currents during the middle Permian

During Permian stage 6 (Wordian, Kazanian) the Pangaean supercontinent was surrounded by a superocean: Panthalassa. An ocean general circulation model has been coupled to an atmospheric energy balance model to simulate the sensitivity of the Wordian climate (∼265 million years ago) to changes in greenhouse gas concentrations, high‐latitude geography, and Earth orbital configurations. The model simulates significantly different circulation features with different levels of greenhouse gas forcing, ranging from a strong meridional overturning circulation in the Southern Hemisphere at low CO2concentration (present level) to more symmetric overturning circulation cells with deep water formation in polar latitudes of both hemispheres at high CO2concentration (8 times present level). The simulated climate with 4 times present level CO2concentration agrees generally well with climate‐sensitive sediments and phytogeographic patterns. The model simulates strong subtropical gyres with similarities to the modern South Pacific circulation and moderate surface temperatures on the southern continent Gondwana, resulting from a strong poleward heat transport in the ocean. An even more moderate climate is generated if high‐latitude land is removed from the southern continent so that ocean currents can penetrate into the polar regions of Gondwana.

Permian Phytogeographic Patterns and Climate Data/Model Comparisons

The most recent global “icehouse‐hothouse” climate transition in earth history began during the Permian. Warmer polar conditions, relative to today, then persisted through the Mesozoic and into the Cenozoic. We focus here on two Permian stages, the Sakmarian (285–280 Ma) and the Wordian (267–264 Ma; also known as the Kazanian), integrating floral with lithological data to determine their climates globally. These stages postdate the Permo‐Carboniferous glaciation but retain a moderately steep equator‐to‐pole gradient, judging by the level of floral and faunal differentiation. Floral data provide a particularly useful means of interpreting terrestrial paleoclimates, often revealing information about climate gradations between “dry” and “wet” end‐member lithological indicators such as evaporites and coals. We applied multivariate statistical analyses to the Permian floral data to calibrate the nature of floral and geographical transitions as an aid to climate interpretation. We then classified Sakmarian and Wordian terrestrial environments in a series of regional biomes (“climate zones”) by integrating information on leaf morphologies and phytogeography with patterns of eolian sand, evaporite, and coal distributions. The data‐derived biomes are compared here with modeled biomes resulting from new Sakmarian and Wordian climate model simulations for a range of CO2 levels (one, four, and eight times the present levels), presented in our companion article. We provide a detailed grid cell comparison of the biome data and model results by geographic region, introducing a more rigorous approach to global paleoclimate studies. The simulations with four times the present CO2 levels (4×CO2) match the observations better than the simulations with 1×CO2, and, at least in some areas, the simulations with 8×CO2 match slightly better than those for 4×CO2. Overall, the 4×CO2 and 8×CO2 biome simulations match the data reasonably well in the equatorial and midlatitudes as well as the northern high latitudes. However, even these highest CO2 levels fail to produce the temperate climates in high southern latitudes indicated by the data. The lack of sufficient ocean heat transport into polar latitudes may be one of the factors responsible for this cold bias of the climate model. Another factor could be the treatment of land surface processes and the lack of an interactive vegetation module. We discuss strengths and limitations of the data and model approaches and indicate future research directions.

Late Permian Foraminiferal Biofacies Belts in Turkey: Palaeogeographic and Tectonic Implications

Abstract Upper Permian marine carbonates are distinguished in two contrasting biofacies belts in Turkey. The Southern Biofacies Belt, represented by low-energy inner platform deposits of the Tauride Belt and the Arabian Platform, is rich in algae and smaller foraminifera but poor in fusulines. The Kubergandian and Murgabian stages are missing, although the rest of the Upper Permian consists of monotonous, shallow-marine carbonate deposits. The extremely tectonised and fragmented Northern Biofacies Belt includes the Upper Permian of the Karakaya Orogen and outer platform or platform margin deposits of the Tauride Belt. These deposits are rich in parachomata-bearing fusulines comprising Cancellina, Verbeekina, Afghanella, Sumatrina, Neoschwagerina and Yabeina . The reconstructed biostratigraphic scheme indicates that all Upper Permian stages (Kubergandian-Dorashamian) are present. The lateral continuity of the two biofacies belts is detected by the presence of tongues of he Northern Biofacies Belt pinching out in the Southern Biofacies Belt. Upper Permian blocks in the Karakaya Orogen display similar palaeontologic and biofacies characteristics, with the outer platform or platform margin deposits of the Taurides constituting the northernmost extension of the carbonate platform. This platform was probably facing a basin or a trough to the north. The lack of any transgressive Upper Permian deposits resting unconformably on the pre-Permian basement of the Sakarya Continent strongly suggests that such a basin was located between the Late Permian carbonate platform in the south and the basement rocks of the future Sakarya Continent in the north.

Permian climates: Evaluating model predictions using global paleobotanical data

The most recent global icehouse‐hothouse climate transition in Earth history occurred in the Permian. Warmer polar conditions relative to today existed from the middle Permian through the Mesozoic and into the Cenozoic. We focus here on one particularly well-correlated middle Permian stage that postdated the deglaciation, the Wordian (267‐264 Ma), integrating floral and lithological data to determine Wordian climates globally. Paleobotanical data provide the best means of interpreting terrestrial paleoclimates, often revealing important information in the continuum between “dry” and “wet” end-member lithological indicators such as evaporites and coals. New statistical analyses of Wordian floras worldwide have enabled a greater understanding of original vegetation patterns and prevailing climate conditions. The derived climate interpretations are compared with new Wordian atmospheric general circulation model simulations. The model matches the data well in the tropics and northern high latitudes, but predicts colder conditions in southern high latitudes. We discuss possible reasons for this discrepancy.