Irkutsk Coal Basin Research Articles

Pollen grains associated with Karkenia irkutensis Nosova (Ginkgoales) from the Jurassic of Siberia

Pollen grains found on the nucellar cuticle and the outer cuticle of the integument of Karkenia irkutensis ovules from the Middle Jurassic of the Irkutsk Coal Basin in Siberia were studied with light and transmission electron microscopies. The overwhelming majority of the pollen grains are non-saccate, boat-shaped and monosulcate and can be ascribed to Cycadopites, which fits to what we expected to find in association with ginkgoalean macrofossils. In addition, several non-saccate and bisaccate pollen grains were also detected and interpreted as alien pollen of wind-pollinated conifers. The Cycadopites pollen grains showed from moderate to poor preservation of the exine ultrastructure, that restricted us from decisive conclusions. Differences in the exine ultrastructure among the sectioned Cycadopites pollen grains are probably due to the insufficient preservation and different angles under which the pollen grains were sectioned, and the Cycadopites pollen most probably derived from the same plant. The ectexine is more electron-dense and much thicker than the endexine, which is not always preserved. The ectexine is predominantly homogeneous, but rare cavities of irregular size and shape (=alveoli) are present in a row in the deep layers of the ectexine. Towards the aperture, the ectexine becomes thinner and can acquire a crenulate outer contour (that means a more distinct surface sculpturing). The exine is usually broken over the aperture. This set of characters is more similar to Ginkgo-type of the exine ultrastructure than to Aegianthus- and Sorosaccus sp.-types, which we defined for ginkgoaleans.

Сходство и различие состава среднеюрских и нижнеплиоценовых отложений на северо-западном берегу Байкала: Оценка вклада обломочного материала Приморского хребта в аллювий средней части долины Пра-Манзурки

A comparative analysis is performed between compositions of pebbles and sandy filler of a pebble package that finalizes a section of the Lower Pliocene Buguldeyka alluvium horizon in the middle part of the Pra-Manzurka valley and those of pebbles and sandy cement of the Middle Jurassic conglomerates of the Nizhniy Koty sub-formation from outcrops of the Angara-Koty depression in the southeastern part of the Irkutsk coal basin. A partial similarity in major oxide and trace element contents in trachydacites and rhyolites of pebbles from Pliocene and Jurassic deposits is defined. From the difference in major oxide and trace element contents of the sand filler of the lower and upper layers of the pebble package of the Pra-Manzurka valley, the difference in their sources is inferred. It is proposed that the convergence between the composition of the sandy filler of the lower layers of the Pliocene pebble package and those of the trachydacite-rhyolite pebbles from this and of the sand cement of the Middle Jurassic conglomerates may reflect the erosion of the clastic material of the Middle Jurassic conglomerates and its removal into the middle part of the Pra-Manzurka valley in the initial phase of the uplift of the Primorsky Range. Occurrence of a Th/Co anomaly in the lower layers of the pebble unit, not typical for Jurassic conglomerates, indicates the formation of the pebbles from another source of clastic material.

Monocotyledon‐like Leaves from the Middle Jurassic of East Siberia (Russia)

AbstractLeaf fragments of Herbifolia antiqua A. Frolov et Enushchenko gen. et sp. nov. from the Middle Jurassic (Aalenian) of the Irkutsk Coal Basin (Eastern Siberia, Russia) are reported. The following features are characteristic of H. antiqua gen. et sp. nov.: the presence of leaf sheaths, linear smooth‐edged leaves with parallel venation, anastomoses between the veins, anomocytic stomata, rhomb‐shaped ordinary epidermal cells. Such a combination of characters is widespread in modern monocotyledonous plants and is absent in fossil and modern cryptogam and gymnosperms. Due to the lack of evidence of an enclosed ovule in H. antiqua gen. et sp. nov., we attribute it to a typological angiosperm, based on its unique leaf structure characteristic of monocotyledons. The leaf epidermal structure of Herbifolia gen. nov. is most similar to those of modern Asparagales and Liliales.

The Prisayan Formation (Lower and Middle Jurassic) of the Irkutsk Coal Basin: New Data on Litho- and Phytostratigraphy

Abstract —The demand for detailed bio- and lithostratigraphic research of the Prisayan Formation is significant because of the lack of its stratotype section. This leads to confusion about the meaning of the stratigraphic volume of the Prisayan Formation. On the basis of the results of a comprehensive research, a lectostratotype section that covers the whole section of the Prisayan Formation is proposed. The following three subformations are identified in the formation on the basis of lithological criteria: lower (Ust-Balei), middle (Idansk), and upper (Sukhov). Stratigraphic correlation of the Prisayan Formation with the coeval deposits of the West Siberian Plate is carried out. The common development trends of typical units of the flora of the Siberian paleofloral region are revealed in West Siberia and the Irkutsk Basin. The observed tendencies make it possible to compare the beds with Coniopteris murrayana, Sphenobaiera czekanowskiana from the lower subformation with the fossil plant assemblage of the Sharapovo Horizon; the beds with Coniopteris snigirevskiae from the middle subformation with the fossil plant assemblage of the Nadoyakh Horizon; and the beds with Raphaelia diamensis and Phoenicopsis irkutensis with the fossil plant assemblage of the Laidin Horizon of West Siberia. The Prisayan-1 palynoassemblage (PA) from the lower and middle subformations correlate with palynozones 5–7 of West Siberia. The Prisayan-2 PA corresponds to palynozone 8 of West Siberia. The paleobotanical and palynological data suggest that the stratigraphic volume of the Prisayan Formation is the upper Pliensbachian–Aalenian of the Lower–Middle Jurassic. This paper touches upon the history of accumulation of the Prisayan Formation, as well as the evolution of the paleorelief and vegetation.

ОЦЕНКА ПЕРСПЕКТИВ РАЗВИТИЯ ЧЕРНОЙ МЕТАЛЛУРГИИ ИРКУТСКОЙ ОБЛАСТИ НА ОСНОВЕ РЕСУРСОВ ВОСТОЧНЫХ САЯН И ИННОВАЦИОННЫХ ТЕХНОЛОГИЙ

The creation of the East Siberian metallurgical base is an indispensable condition for the implementation of reindustrialization processes, including industrial and civil construction, engineering for the mining industry, the chemical industry, etc. The existing opportunities are the formation of a promising heavy-duty iron ore base for the Urals and Western Siberia based on the Bakcharskoye deposit causes the creation in Eastern Siberia of mining and metallurgical enterprises, mainly of local importance. Perspective restrictions on the use of natural gas in iron production, environmental and investment restrictions for blast-furnace production determine the use of liquid-phase iron reduction technologies using thermal coals. The concentration of groups of iron ore deposits in the Irkutsk region makes it possible to create mining and metallurgical plants near the cities of Ust-Ilimsk, Taishet, Tulun. The involvement of significant resources of titanomagnetites is possible when solving the problem of developing more efficient technologies for producing metallic titanium. The object of the research is resources of iron-ore and coal deposits in the Irkutsk region in the process of assessing the possibility and efficiency of their use in the prospective mining and metallurgical industries. The subject of the research is technological and resource prerequisites for location of large objects of mining-metallurgical complexes for direct production of iron in Irkutsk region. The aim of the research is to identify promising deposits and occurrences of iron ore and coal raw materials, taking into account the possibilities of application of existing technical and technological solutions for transportation, enrichment and metallurgical processing for complex processing. The objectives of the research are: to assess the potential of large iron ore deposits of Western Siberia using new technologies to meet the needs of metallurgical enterprises in the Urals and Kemerovo region; to determine a new concept of promising metallurgical base of Eastern Siberia; to determine a promising base for the placement of mining and metallurgical plants in the Irkutsk region. Methodology and research methods. The research methodology is based on a systematic representation of the mining-metallurgical complex created on the territorial combination of raw materials and fuel in accordance with the theory of energy-production cycles, in which promising (innovative) technologies are implemented. When determining the degree of priority development of titanium-magnetite deposits, the possibility of using the resulting titanium-containing products is taken into account. It is also shown that the main metallurgical base of the Irkutsk region can be created in the area of the city of Tulun on the basis of the use of iron ore resources of the Eastern Sayan. The fuel base is provided by the resources of the Irkutsk coal basin. To reduce investment and current costs associated with the transportation of coal and ore or concentrates, it is proposed to use slurry pipelines

Impurity Elements in Coals from the Mugunsk Deposit (Irkutsk Coal Basin)

Impurity Elements in Coals from the Mugunsk Deposit (Irkutsk Coal Basin)

Ovule-bearing structures of Karkenia Archangelsky, associated dispersed seeds and Sphenobaiera leaves from the Middle Jurassic of East Siberia, Russia

Ovule-bearing structures of Karkenia are recorded from the Middle Jurassic of East Siberia for the first time. A new species, Karkenia irkutensis sp. nov., described from the lower part of the Prisayan Formation (Aalenian) of the Irkutsk Coal Basin, is a compact, ellipsoidal to spherical structure consisting of numerous ovules. The entire structure is borne on a thin stalk. The pedicels of individual ovules are also thin and most likely recurved. Four membranes are preserved in the ovules: outer and inner cuticles of the integument, the nucellar cuticle, and the megaspore membrane. Additionally, numerous large resin bodies occur in the sarcotesta. Among the ovules of the same ovule-bearing structure, two types of the megaspore membrane with different ultrastructure were obtained, which may indicate different stages of ovule development. Ovule-bearing structures of K. irkutensis were found in association with leaves of Sphenobaiera vigentis and their co-occurrence in the same samples from the Irkutsk Basin suggests that these remains were most likely produced by the same plant. Numerous dispersed seeds described as Allicospermum sp. were also found in the same locality. These seeds are similar to the attached ovules of K. irkutensis in form and size, but differ in having a thicker sarcotesta, smaller resin bodies. There are also differences in some features of the outer epidermis of the integument. Allicospermum sp. may represent more mature seeds/ovules of K. irkutensis. The morphology and epidermal features of the genus Karkenia are discussed.

Female reproductive structures of Umaltolepis Krassilov and associated leaves of Pseudotorellia Florin from the Middle Jurassic of East Siberia, Russia

Female organs of Umaltolepis are recorded from the Middle Jurassic of East Siberia for the first time. A new species, Umaltolepis irkutensis, sp. nov., is described from the Aalenian–Bajocian Prisayan Formation of the Irkutsk Coal Basin. It is notable for having papillae on some subsidiary cells of the stomatal complexes, on some ordinary epidermal cells of the middle part of the lobes and on the cells near the lobe bases. Cupules of U. irkutensis were found in association with Pseudotorellia leaves described here as a new species Pseudotorellia irkutensis, sp. nov. Leaves of this species are long and narrow, they are peculiar in possessing predominantly short epidermal cells on the adaxial side of the leaf, ordinary epidermal cells with smooth periclinal walls, stomata arranged in not always clear bands on the abaxial side of the leaf, and the presence of papillae on the subsidiary cells of the stomata. The co-occurrence of U. irkutensis with leaves of P. irkutensis in the same samples from the Irkutsk Basin, as well as their similar epidermal pattern, suggests that these remains most likely belonged to the same Umaltolepis–Pseudotorellia plant. The morphology and epidermal features of Umaltolepis female organs are discussed.

Revision of existing classification of fossil insect feeding traces and description of new ichnotaxa from Middle Jurassic sediments of Eastern Siberia (Russia).

This paper revises the existing system of formal classification by Vialov and Vasilenko for fossil plants involving insect feeding and oviposition. The classification of these fossil traces has been amended and supplemented in accordance with the requirements of the International Code of Zoological Nomenclature. The following nomenclatural combinations are made: Insectophagichnata (Vialov) Enushchenko and Frolov, comb. et stat. (classis) nov., Phagolignichnidina (Vialov) Enushchenko and Frolov, comb. et stat. (subordo) nov., Phagophytichnidina (Vialov) Enushchenko and Frolov, comb. et stat. (subordo) nov. Fossil traces of these interactions were found and illustrated for Mesozoic insects and leafes of Ginkgo tapkensis from Middle Jurassic sediments of the Irkutsk Coal Basin in Eastern Siberia, Russia. The examined traces consist of ovipositions (traces of insect egg laying), galls (traces of insect caused teratologies) and epidermal punctures (traces of piercing and sucking). The following ichnotaxa are described and illustrated: Paleoovidinae Enushchenko and А. Frolov, ichnosubfam. nov., Paleoexoovoidinae Enushchenko and Frolov, ichnosubfam. nov., Sugophytichninae Enushchenko and А. Frolov, ichnosubfam. nov., Sugophytichnida pertusura Enushchenko and Frolov, ichnogen. et ichnospec. nov., Paleoovidus vasilenkoi Enushchenko and А. Frolov, ichnospec. nov., Paleoexoovoida ovoidea Enushchenko and А. Frolov, ichnogen. et ichnosp. nov., Paleogallus vialovi Enushchenko and Frolov, ichnospec. nov. Punctures of the leaf epidermis probably belong Mesozoic cicadas of the Palaeontini, which dominate the adjacent strata of the studied location. The extremely low occurrence of interaction between insects and plants in these Jurassic deposits of Eastern Siberia have ichnotaxonomic importance for understanding the functioning of Jurassic terrestrial paleoecosystems.

Age of the coal accumulation in the Irkutsk basin based on accessory zircon dating in the Azeisk deposit tonstein (LA-ICP-MS)

The Irkutsk Coal Basin is located in the south of the Siberian Platform. The deposits of the basin are represented by Jurassic continental sediments. Since the 1970s, tuffs and tuffaceous rocks have been found in sediments of the Irkutsk Coal Basin, but so far only fragmentary information has been available on them. Previously, the age of sediments in the Irkutsk Basin was determined by the biostratigraphic method. We studied a section of the Cheremkhovo Fm., the most ancient formation of the basin, at the Azeisk coal deposit (in the area of the town of Tulun) with the aim of obtaining a geochronological constraints on the timing of sedimentation. The paper shows that tonsteins, which are transformed to clay ash-fall layers within coals, are suitable for radioisotope dating by accessory zircons. U-Pb dating of accessory zircons in tonstein from an industrial coal seam was performed using the LA-ICP-MS method. The obtained U-Pb age of 187.44 +0.45 –1.60 Ma, falling into the Pliensbachian Age, indicates the period of maximum coal formation in the Irkutsk Basin. This is the first radiometric age determination for the timing of accumulation of coal in the Irkutsk Basin. In the context of paleogeographic reconstructions, this age determines the upper limit of the tectonic quiescence period, which created conditions for lacustrine-boggy sedimentation in the vast territory of the Irkutsk Basin.

Maceral and Chemical Compositions of Brown Coals from the Mugunsk Deposit

The results of the petrographic and chemical analysis of brown coal from the Mugunsk deposit in the Irkutsk Coal Basin are presented. The most common groups of macerals and a number of toxic and potentially toxic elements were identified.

The morphology and ultrastructure of Jurassic in situ ginkgoalean pollen

A fragmentary pollen organ with four to six microsporangia is discovered from the Middle Jurassic of the Irkutsk coal basin, Siberia. The in situ pollen grains are boat-shaped, monosulcate, and with a nearly psilate surface. The non-aperture ectexine is composed of a thick solid tectum, a thin infratectum, and a thin foot layer. The infratectum includes one row of small rare alveolae. The supposedly poorly preserved endexine is thin and grainy. The ectexine reduces greatly in the aperture area, where only homogeneous ectexinal patches are present over the endexine. The pollen grains under study resemble in their exine ultrastructure pollen grains of the modern Ginkgo biloba and pollen grains from dispersed seeds of a presumably ginkgoalean affinity from the Middle Jurassic of Uzbekistan. This suggests that the ginkgoalean exine ultrastructure of the modern type existed as early as the Middle Jurassic. The exine ultrastructure under study is also similar, though to lesser degree, to that of dispersed pollen grains of a presumed ginkgoalean affinity from the Cretaceous of the Russian Far East. The diversity of such a long-living group as ginkgoaleans is apparently reflected in the diversity of their exine ultrastructure. To the present knowledge, ginkgoalean pollen grains can be differentiated from similar boat-shaped monosulcate pollens by the following co-occurring characters: a thick homogeneous tectum, a thin infratectum with one row of structural elements, a thin foot layer, and an ectexine that is reduced in the aperture region to patches.

A New Species of Marskea Florin (Pinopsida) from the Middle Jurassic of the Irkutsk Coal Basin (East Siberia)

The study of conifer twigs from the Middle Jurassic deposits of the Irkutsk Coal Basin, previously described as Sequoia and Taxocladus, shows their morphology and epidermal characters to be similar to those of Marskea leaves. A new species Marskea heeriana N. Nosova et Kiritch. is described. A new combination, Marskea latifolia (Kiritch.) N. Nosova, comb. nov., is proposed for leafy twigs from the Early Cretaceous of the Lena Basin, originally described as Florinia latifolia Kiritch.

Sorosaccus sibiricus Prynada (Ginkgoales) from the Middle Jurassic deposits of the Irkutsk Coal Basin, Eastern Siberia

New findings of pollen cones of Sorosaccus sibiricus Prynada were studied in detail from the Aalenian—Bajocian Prisayan Formation of two localities in the Irkutsk coal basin (Ust’-Baley and Vladimirovka). Specimens of S. sibiricus previously described from Ust’-Baley (Heer, 1876) were reexamined. It was revealed that S. sibiricus differs from other species of Sorosaccus in a shape of the apical (free from the microsporangia) part of the microsporophylls. Microsporophylls of S. sibiricus consist of a petiole and a wide-oval distal lamina with acute apex, commonly bending upward. The lamina was often folded and became lanceolate, linear, or fan-shaped with uneven to toothed margin. Microsporangia (6—8) are oval in outline, helically attached to the petiole. Pollen grains were extracted from S. sibiricus microsporangia for the first time. They are oval to boat-shaped in outline, monosulcate and differ from other known Sorosaccus pollen grains by the verrucate surface of the exine. The diagnosis of the species Sorosaccus sibiricus is emended.

Jurassic continental deposits in the sections of the Irkutsk Coal Basin stratoregion

This paper presents bed-by-bed description and paleofloristic characterization (on the basis of plant macroremains) of the Jurassic continental deposits of the Irkutsk Coal Basin, in the sections of the stratotype region where the lithostrata now widely used for the geological mapping works were established for the first time. The characteristics of these units are refined along with their age and occurrences. Newly obtained taphofloras are comparatively analyzed and established to be synchronous. The spatial distribution of Jurassic deposits from different outcrops is correlated with sections of the reference boreholes. Two successive phytostratigraphic assemblages, Cheremkhovo and Prisayan, are recognized. These assemblages are correlated based on the taxonomic composition of the dominant plant groups, with the assemblages of the end of the Early Jurassic and the beginning of the Middle Jurassic of Western Siberia, which are dated using coastal marine fauna.

Provenance change in the Irkutsk coal basin during the early and middle Jurassic: Geochemical and Sm-Nd isotope evidence

On the basis of the recently accepted chronostratigraphic chart, Jurassic sedimentation in the Irkutsk coal basin took place over a short time interval (~23 My), from the Pliensbachian (~191 Ma) to the Aalenian (~170 Ma). In this study, we present geochemical and Sm-Nd isotope data for sedimentary rocks of the Prisayan and Kuda formations and those in the upper course of the Angara River, which were deposited over an even shorter time interval (from ~174 to 170 Ma), as indicated by new data on biostratigraphy. Our results suggest that a greater contribution from Transbaikalia compared to that from the Siberian Platform during sediment deposition in the Irkutsk coal basin may reflect the onset of mountain building in Transbaikalia and reorganization of the river drainage network during the Middle Jurassic.

Leafy shoots and pollen cones of conifers from the Middle Jurassic deposits of the Irkutsk Coal Basin

Among the numerous remains of the Jurassic conifers in the Irkutsk Coal Basin, several types of leafy shoots are distinguished. One type is characterized by the leaves with numerous veins. These remains were described as Podozamites irkutensis N. Nosova et Kiritch. (Nosova et al., 2017). The leaves of other types have a midvein. These leafy shoots are attributed to several taxa: Marskea sp. nov. (in press), Elatocladus falcatus (Heer) Prynada, E. heeriana N. Nosova et Kiritch., sp. nov., Elatocladus sp. and Pagiophyllum sp. Elatocladus falcatus (Heer) Prynada, 1962 (=Elatides falcata Heer, 1976) was described from the deposits of the lower subformation of the Prisayan Formation (the Aalenian) of the Ust’-Baley locality. An epidermal structure of the Elatocladus falcatus leaves is unknown. Here we designate the lectotype for E. falcatus. We have studied the leaf epidermal structure of the leafy shoots from the upper subformation of the Prisayan Formation (the Aalenian-Bajocian) in the localities Topka and Vladimirovka. Based on the morphological and epidermal features, we describe a new species Elatocladus heeriana. The shoots of E. heeriana have with helically arranged leaves. The leaves are sessile and dorsoventrally flattened, linear, lanceolate to falcate, with the tip curving toward the apex of the stem, with the broad and decurrent base and acute apex. The leaves are hypostomatic. They are characterized by straight to undulating anticlinal cell walls of the abaxial epidermis near the leaf edge and base. Stomata are arranged in two narrow bands, orientated transversely to irregularly. Subsidiary cells of the stomatal complexes are without papillae. Rare fragments of the Pagiophyllum sp. shoots were found in the deposits of the upper subformation of the Prisayan Formation (the Aalenian–Bajocian) in the localities Olkha and Vladimirovka. Their leaves are falcate, with a median keel on the abaxial side. The bad preservation of the cuticle did not allow us to study the epidermal pattern in details. Stomata are arranged in the bands, orientated irregularly. Subsidiary cells of the stomatal complexes are without papillae. One pollen cone (microstrobilus), attached presumably to the E. heeriana shoot, and several detached pollen cones of Schidolepium gracile Heer (1880) were found. The pollen cones are elongated, with numerous imbricate, helically arranged and dorsoventrally flattened microsporophylls. Sterile part of the microsporophyll expands to the distal lamina with acute apex. Some microsporophylls near the cone base are oval with rounded apex. The numerous microsporangia are visible in the apical part of the mature pollen cone, but a distal lamina of the microsporophylls often is indistinct here. Microsporangia (5–7 per microsporophyll) are elongated, fusiform. Pollen grains are spherical, nonsaccate, with the rugulate-perforate surface, apertures are invisible. The emended diagnosis is provided for the type species S. gracile, as well as the lectotype is designated.

Waste Water Treatment from Petroleum Products Using Carbon Sorbents and Wastes of Foam Polymers

The results of a study of the sorption of petroleum products (PP) from aqueous solutions by sorbents based on brown coal and polyethylene foam are presented. The possibility of significant decrease in PP concentration when using crumb of polyethylene foam (the first stage of purification) and lowering the content of PP to the value of MPC and lower when using a carbon sorbent based on brown coals of the Irkutsk coal basin (the second stage) is shown. The process of PP sorption was investigated under static and dynamic conditions. The concentration of PP varied from 5 to 500 mg/l. Investigation of PP sorption in the joint use of carbon sorbent and production waste showed high efficiency.

Reconstruction of mid-Jurassic vegetation of the Irkutsk coal basin

Reconstruction of mid-Jurassic vegetation of the Irkutsk coal basin

Род Sphenobaiera Florin (Ginkgoales) и его значение для стратиграфии юрских отложений Иркутского угленосного бассейна

Род Sphenobaiera Florin (Ginkgoales) и его значение для стратиграфии юрских отложений Иркутского угленосного бассейна