Monosaccate Pollen Research Articles

Paleontology of Pennsylvanian transgressive deposits in northwestern Precordillera, San Juan province, Argentina

In central-western Argentina, sedimentological and paleontological studies have identified changes in sea levels during the Pennsylvanian period. After the late Serpukhovian-early Bashkirian postglacial transgression, two main flooding events occurred. Among these, Pennsylvanian transgressions 1 and 2 are considered the most significant. New palynological samples recovered from the T1 transgression in Puesto Volcán, western Precordillera (San Juan province) reveal the presence of the Raistrickia densa-Convolutispora muriornata (DM) Biozone. The palynofloras are characterized by the recognition of Ahrensisporites cristatus, Lundbladispora spp., Raistrickia densa, Spelaeotriletes ybertii, and monosaccate pollen grains. The composition of the assemblages includes some taeniate pollen grains suggesting their assignment to the Subzone B. A new orthoconic cephalopod was also identified in the same stratigraphic interval, which adds to the invertebrate faunal record and confirms the marine environment. Imprints of foliage of Fedekurtzia argentina complete the paleofloristic assemblage. A late Bashkirian-earliest Moscovian age is suggested according to the well constrained radiometric control of the palynostratigraphy in the region.

Palynological assemblages from the Majaditas Formation (Carboniferous), Argentina: An example of reworking in glacial sediments

Reworked palynomorphs are commonly found in sedimentary deposits of glacial environments. However, instances of reworking were few times identified in the Carboniferous assemblages of central-western Argentina. In this study, two well-preserved palynological assemblages recovered from shales bearing dropstones of the Majaditas Formation in San Juan province are described for the first time. The palynoflora comprises spores, monosaccate pollen, acritarchs, and prasinophyte. Although in a low proportion (at least 2%), some palynomorphs correspond to reworked specimens of the underlying Devonian and Mississippian successions. The assemblages are indicative of the Subzone A of the Raistrickia densa/Convolutisporamuriornata Biozone that characterizes the late Serpukhovian-early Bashkirian in the country. Close similarities are evident with other palynofloras described for glaciogenic deposits of the same age in the region.

Palynology and palynofacies of the Permian Paso Aguiar and Yaguarí formations (Paraná Basin, Uruguay): Paleoclimatic, paleoenvironmental, and biostratigraphic implications

The palynological information of the Paso Aguiar Formation (Paraná Basin, Uruguay) is scarce, and the overlying Yaguarí Formation has been hitherto considered as barren. In this study, the palynology and palynofacies of 17 samples recovered from borehole DINAMIGE 943 “Estancia El Águila”, drilled in the Cerro Largo Department (northeastern Uruguay), are analyzed. Palynological assemblages are dominated by striate bisaccate pollen grains, mainly those assigned to the genera Staurosaccites and Lueckisporites, and subordinated apiculate monolete and cingulizonate-cavate spores, essentially represented by Thymospora and Lundbladispora, Gondisporites, and Spelaeotriletes, respectively. The assemblages also include non-taeniate bisaccate and plicate-colpate pollen grains, laevigate and apiculate trilete spores, and algae. Moreover, laevigate monolete spores, non-taeniate and taeniate monosaccate pollen grains, and acritarchs are present in low quantities. The diverse palynoassemblages constitute evidence of a source palaeoflora primarily composed of gymnosperms, with important contributions from glossopterids and conifers. This is complemented by sub-dominant ferns and lycophytes, implying seasonally warmer and humid climates. The palynofacies analysis suggests marine depositional environments with terrestrial inputs related to fluvio-deltaic discharges. Proximal-distal variations are inferred for the lower and middle levels of the Paso Aguiar Formation, while high-energy proximal marine settings with variable redox conditions are deduced for the upper Paso Aguiar Formation and the lower Yaguarí Formation. The abundance of spores recorded is noteworthy, particularly when considering the environmental interpretations for these units. However, the influence of differences in preservation among palynomorphs cannot be entirely ruled out. The assemblages are assigned to the Striatoabieites anaverrucosus-Staurosaccites cordubensis Zone of the Paraná Basin in Uruguay. Nevertheless, obtaining additional data from the studied geological units is crucial to enhance and fine-tune the existing palynostratigraphic framework. Considering the radiometric ages available for the Paraná Basin, along with the ages proposed for comparable biozones in the region and assemblages from correlative units in Brazil, a late Cisuralian–late Guadalupian (Kungurian to Capitanian) age is suggested for the studied section.

Paleogeographic records of glacial and terminal glacial palynozones related to the Late Paleozoic Ice Age in the Brazilian portion of the Paraná Basin, Western Gondwana

Among the four palynozones established for the Pennsylvanian–Permian sedimentary succession of the Paraná Basin, two are related to the glacial (AcZ: Ahrensisporites cristatus and CmZ: Crucisaccites monoletus zones) and one is related to the following terminal glacial phase (VcZ: Vittatina costabilis Zone) in this portion of Gondwana. The AcZ and the CmZ are typically recognized within the basal and middle portions of the Itararé Group and the Aquidauana Formation, while the VcZ corresponds to the upper portions of both units. In this paper we present a palynostratigraphic analysis of all occurrences of these palynozones from 66 boreholes and 29 outcrops. Two paleogeographic maps are depicted showing the distribution of all sections where the palyonozones related to glacial and terminal glacial sections occur within the Itararé Group and the Aquidauana Formation. Glacial palynozones (AcZ and CmZ) are recognized from outcrops and boreholes from Santa Catarina, Paraná, São Paulo, Mato Grosso do Sul, Mato Grosso and Goiás states, encompassing the thickest portion of the Itararé Group and the Aquidauana Formation. The terminal glacial palynozone (VcZ) was recognized from several boreholes and outcrops, well distributed throughout the basin, from the Rio Grande do Sul, Santa Catarina, Paraná, São Paulo and Mato Grosso do Sul states. Reworked palynomorphs from Devonian and Mississippian strata found together with indigenous species in assemblages assigned to the glacial palynozones (AcZ and CmZ) are used herein as a tool for interpretation of the source area and as indicators of transport direction. As observed elsewhere in Gondwana, palynozones related to the glacial and terminal glacial phases present dominance of spores and monosaccate pollen grains, whereas those linked to the latter phase record the income and the quantitative increase of certain species indicative of progressive climate amelioration. Further sedimentary and stratigraphical aspects are also discussed.

New age, stratigraphic and paleoenvironmental interpretation of the Loma de los Piojos Formation (San Juan Province, Argentina) based on new palynologic and stratigraphic information

A physical stratigraphic study of the Loma de los Piojos Formation (LPF) and related units at the homonymous locality (5 km north of Jachal city, San Juan Province, Argentina) was carried out. The first palynologic result is presented herein from the shale beds of the Loma de los Piojos Formation, just below the deposits bearing floral remains of the Frenguellia eximia–Nothorhacopteris kellaybelenensis–Cordaicarpus cesarii (FNC) informal zone of Balseiro et al. (Serpukhovian sensu lato). The Loma de los Piojos does not have an exposed base, and the Guandacol Formation (late Serpukhovian–early Pennsylvanian) overlies it. Also, the field work analysis allowed the association of LPF shales with the last depositional sequence of the recently defined and underlying Don Buenaventura Formation, of late Mississippian–earliest Pennsylvanian age. The four fertile samples obtained from the shale beds of the LPF yielded 45 species of terrestrial plants. Monosaccate pollen grains (Cannanoropollis janakii, Cannanoropollis mehtae, Circumplicatipollis plicatus, Crucisaccites monoletus) represent the Cordaitalean and Coniferalean that varied in their frequency c. 25 % in the lower two samples to 34 % and 7 % in the other two. Spore species of lycophytes dominate in all samples (ca. 50–80 %) along with other spores that appeared in the late Serpukhovian–Bashkirian subzone A of the Raistrickia densa–Convolutispora muriornata Palynozone (DMZ). However, in the lowest sample the key spore Spelaeotriletes ybertii and a well-preserved specimen of the striate bisaccate pollen Illinites unicus allowed the correlation with the late Bashkirian–Moscovian Subzone B of DMZ. Therefore, the informal floral zone Frenguellia eximia–Nothorhacopteris kellaybelenensis–Cordaicarpus cesarii is here reallocated to the Nothorhacopteris–Botrychiopsis–Ginkgophyllum (NBG) Zone, which is relevant in the global context of the evolution of the plant groups involved. This dark shale section would correspond to a warmer interval during which the maximum flooding zone was dated c. 320 Ma locally at the Huaco section (also close to Jachal city), also documented across the Paganzo Basin up to the Paraná Basin in Brazil. The three Late Paleozoic mentioned units were deposited within the largest incised valley complex of this region based on the amount of preserved depositional sequences (7), thickness (>1 km), and time span (from Late Mississippian to lower Pennsylvanian). This complex stratigraphic succession formed within a large paleovalley probably acted as a trunk drainage system connecting depositional areas from the continental interior with coastal areas of the Gondwanan continental western margin.

Exceptionally well‐preserved seed cones of a new fossil species of hemlock, Tsuga weichangensis sp. nov. (Pinaceae), from the Lower Miocene of Hebei Province, North China

AbstractTsuga (hemlock) is a small genus of 10 extant species in the Pinaceae, with a disjunct distribution in East Asia and eastern and western North America. Reliable species‐level identification of Tsuga fossils depends on the discovery of seed cones with intact bracts, but such cones are rare in the fossil record. Here we describe a new fossil species of hemlock as T. weichangensis sp. nov. based on exquisitely preserved seed cones with nearly complete bracts from the Lower Miocene of Weichang, Hebei Province, North China. This fossil species displays a mosaic of characters between Tsuga and Nothotsuga. The well‐developed and slightly exserted bract scales of T. weichangensis are reminiscent of Nothotsuga, but other characters, such as nonleaved peduncles and tongue‐shaped bract scales, in addition to monosaccate pollen found at the same fossil locality, suggest an affinity closer to Tsuga. Cladistic analysis based on 15 morphological characters and a molecular backbone constraint supports the assignment of these fossil cones to Tsuga rather than Nothotsuga, and places the fossil species of T. weichangensis in an unresolved polytomy within the genus Tsuga. The occurrence of Tsuga seed cone fossils indicate the paleoclimate in the Miocene of Weichang was warmer and more humid than today's climate, which is consistent with the paleoclimate reconstructed by paleopalynology.

First record of Anisian deposits in the Betic External Zone of southern Spain and its paleogeographical implications

In the External Zone of the Betic Cordillera (S Spain), upper Muschelkalk (Ladinian) facies have been known for decades; however, so far there is no stratigraphic record of Anisian deposits. In the present study, new biostratigraphic data from a carbonate succession in the easternmost Subbetic domain reveal a Pelsonian-Illyrian (Anisian) age. The nautiloids Germanonautilus salinarius and Germanonautilus saharonicus are documented for the first time in the Iberian Peninsula, and together with the brachiopod Tetractinella trigonella and the bivalves Neoschizodus orbicularis and Myophoria vulgaris they represent marker fossils of Anisian deposits previously described from many other basins, both in the Germanic and Alpine realms. The co-occurrence of the nautiloid G. saharonicus and the bivalve Gervillia joleaudi at the top of the studied succession serves as correlation tool for the first faunal migration event from the Sephardic towards the Subbetic domain. The palynomorph assemblage, including the monosaccate pollen grain Cristianisporites triangulatus, provides further evidence of a late Anisian age. An integrated study of fossil assemblages and sedimentary facies reveals tidal and very shallow-marine environments that characterize an extensive epicontinental platform in the western Tethys along the paleo-margin of the Iberian Massif. Two thin shale intervals represent two distinct transgressive phases, correlative to the Pelsonian maximum-flooding zone recorded in other European basins. The new findings contribute to the ongoing paleogeographic reconstruction of epicontinental platform settings which developed during the Middle Triassic in the Peri-Tethyan realm.

Palaeoclimate, Palaeoecology and Palaeovegetation in and around Nandira Colliery, Talcher Basin, Odisha, India during Early Permian: Inferences from Typical Karharbari Palynofloral and Palynofacies Analysis

Abstract Palynofloral study along with palynofacies analysis has been undertaken in Nandira colliery, Talcher basin, Odisha, India. Recovered palynoassemblage is characterized by the dominance of monosaccate pollen grains viz., Parasaccites spp. (25%), Plicatipollenites spp. (5%), Potonieisporites sp. (1%) and Diavarisaccus lelei (1%) along with nonstriate bisaccate Scheuringipollenites maximus (35%). The recovered palynoflora shows its affinity towards the Upper Karharbari palynoflora of the early Artinskian age. The organic matter studied from the palynofacies investigation includes palynomorphs (SP), structured phytoclasts/ translucent phytoclasts (ST), opaque phytoclasts/ charcoal (CH), degraded organic matter (DOM), and amorphous organic matter (AOM). The carbonaceous shale (Sample Na) is dominated by SP (34.67%) and sub-dominated by ST (22%) along with CH (13.34%), DOM (19%), and AOM (11%). Coal samples (Nb to Ne) are completely devoid of palynomorphs. They are mainly dominated by CH (24.87-62.34%) and ST (20.20-73.38%) with presence of DOM (0.7-8.7%) and AOM (0.4-8.7%). Deposition of the sediments in a lower carbonaceous shale bed (Na) might have occurred in a dysoxic forest swamp in low-energy settings. The coal beds (Nb to Ne) have been deposited in the oxidized swamps in the proximal setting. The predominant occurrence of the opaque phytoclasts associated with the coal sediments may indicate a regular occurrence of palaeofires during the Artinskian.

First record of late Carboniferous palynoassemblage from Ganmachidam Formation, Spiti Valley: Implications for age assessment and extent of Glossopterid elements in the Tethyan realm

The present work elucidates miofloral records from the Ganmachidam Formation (late Carboniferous–earliest Permian) of Spiti Valley, Tethyan Himalaya. The Ganmachidam Formation was hitherto considered as unfossiliferous, both for the faunal as well as floral records, and has been subjected to contentious age assessment. The present study has been carried out to find out the microfloral remains, assess the palynostratigraphic status, and the age of the Ganmachidam Formation. From the splintery shale sequence, a rich assemblage of palynomorphs has been recovered, having a dominance of monosaccate pollen grains, namely Parasaccites (Cannanoropollis), Crucisaccites, Divarisaccus, Densipollenites, Maculatasporites, followed by diverse bisaccate pollen grains, namely Scheuringipollenites, Crescentipollenites, Faunipollenites (Protohaploxypinus), Lunatisporites, Striatopodocarpites, Striatites, Rhizomaspora, Primuspollenites, and the spores Callumispora (Punctatisporites) and Calamospora in addition to woody fragments and fungal spores. Three palynoassemblages are identified. The recovered palynocomposition is corroborated with known records of palynomorphs from the Tethyan realm of India and from the late Carboniferous–Early Permian records of contemporaneous sequences across the globe. The composition of these palynoassemblages shows close correlation with the Crucisaccites monoletus Zone and Vittatina costabilis Interval Zone in the northeastern area of the Paraná Basin, Brazil, and lower Barakar palynozone (Scheuringipollenites barakarensis Assemblage Zone) of Peninsular India which indicates the studied section of the Ganmachidam Formation is late Pennsylvanian to early Permian in age. Moreover, occurrences of palynomorphs from the Carboniferous sequences having a glossopterid affinity further strengthen the idea that glossopterids might have originated in Carboniferous time.

Upper Pennsylvanian Age of the Lower Talchir Formation in the Wardha Basin, Central India, Based on Guide Palynomorphs Present in Radiometrically-Dated Palynozonations in South America, Africa, and Australia

The age of the Talchir Formation corresponding to the lower part of the Gondwana (Permo–Carboniferous) Sequence in India is revised in the light of palynostratigraphic data associated with radiometric dating generated in Gondwana. New data was generated from seven samples of the Talchir Formation obtained from Well 131, located in the Penganga area of Wardha Valley Coalfield (Maharashtra State, central India). Two assemblages were demarcated based on the stratigraphic distribution of 63 species of spores (23 taxa), pollen grains (35 taxa), and phytoplankton. Palynoassociation I recognized in the two basal samples yielded few Punctatisporites spores and monosaccate pollen grains. Palynoassociation II is demarcated in the overlying three samples characterized by spores and pollen grains that are more diversified and abundant than in the other two samples. Several taxa (Concavissimisporites grumulus, Converrucosisporites confluens, Cyclogranisporites gondwanensis, Verrucosisporites andersonii, Latusipollenites quadrisaccatus, Marsupipollenites striatus, Pakhapites fusus, Striatoabieites multistriatus, Vittatina subsaccata, Vittatina vittifera) are shared with palynozones radiometrically constrained to the latest Pennsylvanian–early Cisuralian in Argentina, Brazil, Africa, and Australia. Therefore, we propose a Kasimovian to Ghezelian–Asselian age for the palynoassociations I and II of the Talchir Formation and a correlation with the Potonieisporites neglectus and Plicatipollenites gondwanensis Zones of Tiwari & Tripathi, respectively. This approach significantly improves the stratigraphic correlations of the Indian palynozones in Gondwana.

The Vittatina costabilis Zone revisited: New characterization and implications on the Pennsylvanian-Permian icehouse-to-greenhouse turnover in the Paraná Basin, Western Gondwana

The accuracy of the radiometric ages for the Pennsylvanian-Permian section of the Paraná Basin has been progressively increased in the past two decades, allowing a better chronostratigraphic calibration to the related biozones. Most of these new ages are from levels containing spore-pollen associations assigned to the Vittatina costabilis Zone (VcZ), which is revised in detail herein. Unlike previous biostratigraphic proposals, we verified that VcZ is positioned between the Gzhelian and the Artinskian, documenting the Pennsylvanian-Permian transition. A new palynological characterization is proposed for this palynozone, including (i) changes in the definition of its lower and upper limits and (ii) the invalidation of its subzones. Although spores and monosaccate pollen grains are dominant in the VcZ, gymnospermic taeniate bisaccate and polyplicate pollen grains become progressively more abundant up section, representing new plant groups mainly linked to gymnosperms and allied groups. The VcZ documents the first appearance of certain Gondwana taxa of stratigraphic value, such as Converrucosisporites confluens and several species of Vittatina. The stratigraphical distribution of the VcZ is redefined based on previous and unpublished data. In general, the zone is well developed along the basin, but it is better represented between Santa Catarina and São Paulo States. No palynostratigraphic changes were consistently observed throughout the palynozone, which is recognized into two lithostratigraphical units of distinct paleoclimatic nature: the upper Itararé Group and the Rio Bonito Formation. Considering that earliest appearance of the Glossopteris in Paraná Basin is recorded within the upper Itararé Group from levels bearing palynological associations assigned to the VcZ, a Pennsylvanian age is evidenced for this plant group, which only became dominant across the Gondwana areas in Permian times.

Update of the Pennsylvanian palynostratigraphy from central-western Argentina

The Raistrickia densa-Convolutispora muriornata (DM) palynological assemblage biozone formerly proposed twenty years ago for Pennsylvanian successions of central-western Argentina is at present represented in fifty stratigraphic sections. The advances in the studies, with detailed paleoenvironmental data and sampling with precise provenance through complete successions, allow the range of several species to be constrained. The biohorizons and composition of the three subzones (A, B, and C) are updated according to a revision of 400 palynological samples, and a new proposal of subdivision is presented. Of stratigraphic importance in the characterization of the DM Biozone are the presence of Lundbladispora braziliensis and radial monosaccate pollen at the lowermost boundary and the appearance of Pakhapites fusus and Vittatina costabilis at the uppermost biohorizon. Subzone B is recognized by the occurrence of Spelaeotriletes ybertii and bisaccate taeniate pollen, while Subzone C is distinguished by the first occurrence of Raistrickia cephalata and increase of taeniate pollen (including Vittatina). Variations in diversity are discussed concerning paleoenvironments, and floristic changes, as well as a comparison with other Gondwanan assemblages is presented. Absolute datings indicate that the age of the Subzone A is constrained within the late Serpukhovian-early Bashkirian, the Subzone B to the late Bashkirian-earliest Moscovian, and the Subzone C to the Moscovian-Kasimovian? The accurate U–Pb zircon CA-TIMS calibration for the DM Biozone allows constraining the stratigraphic range of its species and the correlation with other Gondwanan regions.

New Middle Triassic Pollen Taxa of the San Rafael Basin, Mendoza Province, Argentina

New pollen grains are described from diverse palynological assemblages recorded from the Quebrada de los Fósiles Formation, lower unit of the Puesto Viejo Group, San Rafael Basin (Mendoza, Argentina), southwestern Gondwana. Two new pollen genera, Mendozapollenites gen. nov. and Crackipollenites gen. nov., are proposed. Also, three new species, Mendozapollenites variabilis sp. nov., Angustisulcites hexagonalis sp. nov. and Crackipollenites polygonalis sp. nov., as well as Crackipollenites sp. A and an indeterminate monosaccate pollen (Form A), are fully described and illustrated. The microflora contains: high proportions of sphenophyte and lycophyte spores; true ferns and bryophyte spores as minor components; non-taeniate pteridosperm bisaccate pollen grains; taeniate monosaccate and bisaccate pollen, scarce monosulcate and inaperturate grains, among other less frequent gymnosperm pollen; and the co-occurrence of chlorococcalean algae and fungal spores. The sedimentation of the Quebrada de los Fósiles Formation took place during the Ladinian (Middle Triassic), as was confirmed by recent radiometric dating of ignimbrites from the base and the top of the main profile of the unit. Thus, this is the first unequivocal and unique microflora recorded at present for the Ladinian in South America.

Palaeoenvironmental Interpretation of the Upper Triassic Baluti Formation in two selected sections at Amediya District, Kurdistan Region- Iraq: Insights from Palynofacies Study

Palynofacies analysis was carried out on 28 outcrop samples from the Upper Triassic Baluti Formation from Zewa and Sararu Sections in south and northwestern of Amediya District respectively, Kurdistan Region- Iraq. Based on the studied palynofacies, both sections are quite different in terms of depositional environment. Four types of palynofacies were recognized as following: the palynofacies type IV (Pl.1) is observed in the lower, middle and upper portions of upper part of Zewa Section in which, is characterized by high amount of phytoclasts, medium percentage of amorphous organic matter (AOM) and palynomorphs. This facies is referred to a depositional area that is located relatively nearshore with an arid hinterland, the palynofacies type V (Pl.2) was observed in lowermost and middle portions of upper part of Zewa Section, which is characterized by high domination of palynomorphs (mainly bisaccates and monosaccate pollen grains) and a less amount of phytoclasts and AOM. This facies indicates the domination of shallow marine to continent environment. The palynofacies type VI (Pl.3) was observed in middle and upper portions of upper part of the Zewa Section and lower and upper parts of the Sararu Section. This facies showed less amount or absence of palynomorphs, and relatively high amount of AOM and phytoclasts. In addition to this, a remarkable percentage of dinoflagellate cysts in Sararu Section has been found in this facies. This facies indicates proximal suboxic-anoxic shelf, and palynofacies type IX (Pl.4) was observed in middle to upper part of Sararu Section and characterized by less amount or absence of palynomorphs with high amounts of AOM and phytoclasts, which represents a deep environment of deposition.

Timing of the Late Palaeozoic glaciation in western Gondwana: New ages and correlations from Paganzo and Paraná basins

During the Late Palaeozoic, the Gondwana supercontinent formed an extensive Southern Hemisphere landmass that was affected by multiple glacial episodes, known collectively as the Late Palaeozoic Ice Age (LPIA). This resulted in the deposition of glacial, periglacial and deglacial sediments over much of the supercontinent. The Mississippian to early Pennsylvanian phase of glaciation is widely represented along the western margin of Gondwana. This constitutes one of the largest glaciations of the Phanerozoic in terms of its recorded extent and the widespread erosional hiatus it produced in the stratigraphic record. It was this mid Carboniferous glaciation, recorded in the Paganzo Basin of NW Argentina, that carved most of the paleovalleys and paleofjords present there. We report new U-Pb zircon ages from a single glacial succession (Guandacol Formation) of 326 ± 3 Ma and 320 ± 5 Ma, that in comparison with neighbouring dated sequences allow for the first time a reliable estimate of the timing and duration of glacial cycles. Palynological studies of these glacial-deglacial events yielded palynoassemblages of the MQ (Late Visean) and DMa (Sepukhovian-Bashkirian) Palynozones. The Carboniferous glacially-related strata and glacial cycles of the Paganzo Basin are compared here with equivalent units of the Paraná Basin of SE Brazil, suggesting a similar climate record for most of western Gondwana. We propose a new correlation between these two basins. The new U-Pb zircon ages reported here indicate that a regional glacial peak occurred almost coincident with the Mississippian-Pennsylvanian boundary, suggesting that the ensuing postglacial transgression is the best regional marker to differentiate the Mississippian and Pennsylvanian as it forms an identifiable interbasinal horizon. The biostratigraphic and chronostratigraphic comparison with other LPIA successions from South America reinforces that the First Appearance Datum of monosaccate pollen grains occurs in the late Serpukhovian. Their correlation confirms that similar climate conditions prevailed across most of western Gondwana during this phase of the LPIA.

Stratigraphic revision of the El Imperial Formation (Pennsylvanian-Cisuralian), in its type locality, San Rafael Basin(Mendoza), Argentina

The El Imperial Formation (San Rafael Basin) shows a complete record of the late Carboniferous - early Permian stratigraphy in western basins of Argentina. The sedimentological and stratigraphic analysis in the type locality allowed recognizing eight facies associations. Facies association A includes diamictites and conglomerates related to the Late Paleozoic glacial event, facies B composed of shales and fine-grained sandstones, was formed during the postglacial transgression while facies C represents sandy littoral bars, that pass upward to shales and mudstones of the facies association D. The conglomerates and sandstones of the facies association E entirely correspond to fluvial sedimentation, followed by a new transgressive event represented in fine-grained sandstones and shales of the facies F. The last transgression is recorded in shales, mudstones and very fine-grained sandstones belonging to the facies G, which are covered by sandstones and conglomerates corresponding to multi-channel fluvial systems.From these facies associations, 33 palynofloras divided into three palynological associations were obtained. The palynological assemblages that characterized the basal section contain abundant trilete spores and monosaccate pollen grains, with a progressive increase of taeniate pollen towards the top of the unit. The presence of scolecodonts characterizes palynofloras from transitional to marine environments. The composition of the palynofloras allows correlations with the current biostratigraphic scheme of the center-west of Argentina. The presence of the Biozone Raistrickia densa- Convolutispora muriornata in the lower and middle part of the El Imperial Formation, together with Pakhapites fusus-Vittatina subsaccata Biozone in the upper part, allows us to refer the palynofloras to the late Serpukhovian/early Cisuralian.

First Palynological Record from the Upper Carboniferous/Lower Permian Succession in West Beni Suef Basin, Egypt, with Paleoecological and Paleogeographical Implications

FOR THE FIRST time, a palynological assemblage was recovered from the Safi Formation in the west Beni Suef Basin of the Western Desert in Egypt. A total of 65 miospore taxa were recognized; they included 31 species of pteridophyte spores (related to 20 genera) and 34 species of gymnosperm pollen (related to 14 genera). The dominance of monosaccate pollen confirms an age not older than Westphalian (Late Carboniferous) as documented in various Gondwanan basins. Besides the restricted presence and limited counts of typical guide taeniate bisaccate and non-taeniate bisaccate pollen in the present assemblage constrain and limit the age to the Asselian (Early Permian) and not younger. The paleovegetation of the studied palynoassemblage is reconstructed based on the paleobotanical affinities of the identified miospores, which are generally consistent with other macrofloral fossil records obtained from Egyptian outcrops during the Late Carboniferous and Early Permian. The paleoecological significance of the reconstructed paleovegetation enabled the recognition of two paleofloral communities: A lowland paleoflora represented by a cold climate wetland fern community associated with Lycopsida and Sphenopsida and an upland paleoflora dominated by a primitive group of gymnospermic plants with a unique moisture-independent reproduction strategy developed under the influence of a glacial climate. The high representation of the bilaterally or radially symmetrical monosaccate pollen genera, which are typical Late Paleozoic Gondwanan gymnospermic vegetation, in the present material supports the hypothesis that Egypt’s Western Desert was part of the Gondwanan floral province during the Late Carboniferous/Early Permian.

Palynostratigraphy and palaeoenvironment of the Permian sediments in Mand Coalfield, Mahanadi Basin, Chhattisgarh, India

Palynological investigation of 483.00 m deep subsurface Permian sediments of borehole MSK–1, in Sithra–Kurekela Block of Mand Coalfield, revealed four distinct palynoassemblage zones. These palynoassemblages belong to Lower and Upper Barakar (Early Permian), Barren Measures and Raniganj (Late Permian) palynofloras of Indian Gondwana. The oldest Palynoassemblage–I, (Scheuringipollenites barakarensis) recorded between 483.60–309.00 m depths, shows dominance of non–striate bisaccate pollen grains chiefly ― Scheuringipollenites followed by Faunipollenites in association with Indotriradites, Dentatispora, Verrucosispora and Microbaculispora related to Lower Barakar palynoflora. Palynoassemblage–II, (Faunipollenites varius) recorded between 303.40–139.40 m depths, showing the dominance of Faunipollenitesin association with Scheuringipollenites, Striatopodocarpites, Brevitriletes, Horriditriletes and Striamonosaccites, indicates Upper Barakar palynoflora. Palynoassemblage–III, (Densipollenites indicus) recorded between 135.55 to 92.50 m depths, showing the prominence of enveloping monosaccate pollen (Densipollenites) in association with Faunipollenites, Microfoveolatispora, Striatopodocarpites and Verticipollenites, indicates Barren Measures palynoflora. Palynoassemblage–IV, (Densipollenites magnicorpus) recorded between 90.90–27.00 m depths, is characterized by the dominance of striate bisaccate pollen taxa chiefly Striatopodocarpites and Faunipollenites along with Densipollenites, Navalesporites, Distriatites, Hamiapollenites, Crescentipollenites and Guttulapollenites indicating late Permian (Raniganj) age. Raniganj palynoflora has been demarcated in lithologically designated Barren Measures Formation. This is the first report of Late Permian (Raniganj) palynoflora from Sithra–Kurekela area of this coalfield. The age correlation also gets support from comparative studies with similar palynoassemblages known from Indian Gondwana. Palynofloral evidences indicate the prevalence of warm and humid conditions. Dominance of gymnosperms represented by glossopterids, conifers and cordaites along with low percentage of trilete spores (filicopsids and sphenopsids) suggests that the sediments were deposited under fresh to brackish water environment.

Palynomorphs from the Barakar Formation of Dhanpuri Open Cast Mine, Sohagpur Coalfield, Madhya Pradesh, India

Well preserved palynomorphs from the Barakar Formation of Dhanpuri Open Cast Mine, Sohagpur Coalfield, Shahdol District, Madhya Pradesh are reported for the first time. The palynomorphs include megaspores and spores/pollen grains. Dispersed megaspores are represented by 6 genera and 13 species comprising Banksisporites indicus, B. utkalensis, Banksisporites sp., Barakarella shuklae, Barakarella sp., Biharisporites sp. Bokarosporites rotundus, Bokarosporites sp., Jhariatriletes baculosus, Jhariatriletes sp., Talchirella flavata, T. trivedii and Talchirella sp. The microspore assemblage shows dominance of monosaccate pollen grains namely Parasaccites obscures, P. korbaensis and Plicatipollenites indicus, along with sub–dominance of non–striate bisaccate taxa Scheuringipollenites barakarensis and S. maximus. Other palynomorphs include trilete Callumispora barakarensis, striate bisaccate pollen grains Faunipollenites sp. and Striatopodocarpites multistriatus, non striate bisaccate genera Ibisporites diplosaccus and Platysaccus ovatus, along with Tiwariasporis gondwanensis and Vitreisporites sp.

Palynostratigraphy and correlation of the coal bearing Gondwana sediments in the Kothagudem sub basin of the Godavari Graben, South India

The present investigation deals with the palynology of five sections from the Kothagudem sub–basin of the Godavari Graben, India to unravel the biostratigraphy and palaeovegetation. The palynological analysis in the five sections of Rampur, Hemchandrapuram and Kothagudem areas revealed the presence of Karharbari (Palynozone–I), lower Barakar (Palynozone–II) and Raniganj (Palynozone–III) equivalent palynofloras in lithologically designated Barakar Formation. Palynozone–I is dominated by cordaitalean radial monosaccate pollen grains (Parasaccites spp., Plicatipollenites spp.) and trilete spores (Callumispora spp.) which represent colder climatic conditions. Palynozone–II is chiefly dominated by non–striate bisaccate (Scheuringipollenites spp. and Ibisporites spp.) and striate bisaccate (Faunipollenites spp., Striatopodocarpites spp.) grains of conifer and glossopterid origin indicating presence of peat–forming plants and conducive climatic condition for the coal formation. Palynozone–III is mainly dominated by striate bisaccate pollen grains of glossopterid origin along with conifer (Faunipollenites spp., Striatopodocarpites spp., Crescentipollenites spp.) and peltasperm (Falcisporites spp., Chordasporites spp.) pollen grains representing hot and humid conditions. Palynozone–III is characterized by the dominance of striate bisaccate taxa along with stratigraphically significant palynomorphs (Corisaccites sp., Guttulapollenites sp., Lunatisporites sp., Chordasporites sp., Falcisporites sp., etc.). On the basis of palynofloral composition Palynozone–I, II and III have been assigned to the Sakmarian (upper Karharbari), Artinskian (lower Barakar) and Lopingian (Late Permian) age respectively.