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Preliminary results from sculpture analysis of the apiculate miospores from the Upper Visean of Kaluga region, Russia

Mamontov D.A., Orlova O. A.

Geology, Geophysics and Environment

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2016

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Vol. 42, no. 1

95--96

EN

Palynological materials for the present study are well preserved apiculate miospores collected from palynoassemblage MS-6 of Mstikhino quarry, Kaluga Region. The unique palynoassemblage MS-6 has been extensively studied by the authors in recent years (Mamontov 2012, Mamontov & Orlova 2014). The unusual attribute of the assemblage is a great variety of the miospores with transition apiculate sculpture (grain-coni-papillae). However, it remained unclear whether the different ornamentation types had similar ranges of variation within both the sculptural elements and arrangement of the ornaments. The general purpose of the research is comparison of similar sculptural patterns from triangular apiculate miospores based on the range of morphological variation. Preliminary results of sculpture analysis of some apiculate miospores from the locality have been obtained. For the present study thirty specimens of each species Granulatisporites granulatus Ibrahim, Iugisporis subintortus (Kedo) Mamontov comb. nov., Lophotriletes parviverrucosus (Waltz) Kedo were accidentally sampled from the assemblage MS-6. All specimens were examined by the methods of transmitted light and scanning electron microscopy. Additionally we applied the model of sculptural analysis introduced and modified by Vezey et al. (1992). Measurements of sculptural features were carried out by the image-analyzing software ImageJ. Statistical data were summarized in the MS Excel. Thus several sculpture variables have been measured: - average Wadell’s diameter (it is diameter of circle having a same area as a base of the sculpture elements (grain, coni or papillae)); - average height of the elements; - average distance between the edges of adjacent elements; - average polar diameter of spore; - average length of the trilete rays; - spore outline; - quantity of elements on the visible spore hemisphere; - quantity of elements are located along the spore equator. Fifty measurements of the each variable were produced. Range of variation for the features was evaluated by coefficient of variation (CV). As a result of the analysis the three species are defined by continuous variation of the polar outline between triangular concave to triangular with slightly convex sides. Similarities within shape and size of the elements were indicated. Grains, coni and papillae are characterized by similar continuous variation of apices with blunt, pointed and rounded shape. Some of the elements are supplied by bifurcating tops while the other ones are fused by the bases. Amount of the elements is differed within each species. Ornamentation of the Granulatisporites granulatus is restricted by about 290 elements of the proximal hemisphere. The same feature of the Iugisporis subintortus is defined by about 212 coni-like elements. In contrast the Lophotriletes parviverrucosus are attributed by about 170 sculptural unites. All specimens of Iugisporis are characterized by medium coefficient of variation 26% for diameter of the base of the coni (Wadell’s diameter), but the CV of height of the elements is about 35%. Variation of the distance between the coni is extremely high 60%. For the Lophotriletes specimens CV of the Wadell’s diameter is increased up to 30% and variation of the height of papillae became more stronger – 44%. However, there are no differences in CV of the distance between the papillae in comparison to the Iugisporis. Coefficient of variation of Wadell’s diameter for specimens of Granulatisporites is indicated by level 25%. Variability of grain height is about to 30%. However, variance of distance between the adjacent grains is decreased up to 40% in contrast to other species. Variation of the polar diameter and length of rays from the all specimens are inconspicuous changed up to 12%. Additionally specimens of the all species are marked by correlation between amount of elements along the spore equator and concavity of the interradial sides of spore outline. Quantity of the equatorial elements was salutatory increased while the interradial sides became more concave. However it would generally depend on the average polar diameter of the spores. Significantly, size of the sculptural elements unevenly increased ongoing from polar area to equatorial margin of the spores. In additional, continuous variation between granulate, coni and papillae ornamentations have been observed within the studied specimens. Accordingly, all morphological features of the genera Granulatisporites , Iugisporis , Lophotriletes were subdivided into three categories: 1) common characteristics which are more stable: polar diameter, length of rays, spore outline; 2) variable characteristics which are defined by high coefficient of variation: quantity of elements, height of the elements, distance between the edges of adjacent elements, Wadell’s diameter; 3) variable qualitative characteristics: shape, type and distribution of sculptural unites. The results lead us to believe that such qualitative characters as type, shape and arrangement of sculpture elements are strongly connected with measured CV of characteristics from b) category. In accordance to morphon concept introduced by van der Zwan (1979) the group of miospore species is united in morphon by similar continuous variation of morphological features. Therefore, such morphologically similar species have the same range of CV of the coincident sculpture features. However it should be noted that this conclusion are restricted by common occurrence of transitional sculpture variations of the apiculate spores. Also it is possible that different value CV from different variables were caused by the different role of the sculptural feature in natural selection.

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Paleoecological analasis of the miospore assemblages from the borehole 39, Moscow region, Russia

Mamontov D.A.

Geology, Geophysics and Environment

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2015

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Vol. 41, no. 1

106--107

EN

Palynological material was obtained from Upper Visean deposits in the borehole No 39 that is located on the left bank of the Oka River, on 105 km to the south-east of the Moscow in the Serpukhov district. The lithological sequence of the borehole generally consist of the limestones, stigmarian limestones, interbedded with clays and siltstones. Total twenty five palynological samples from the sandy siltstones and charcoal clays (deep interval 29.4–33.25 m) have been collected. All samples contained abundant well-preserved miospores. Two palynoassemblages have been defined. The palynoassemblage S1 is described from the sandy siltstone and stigmarian limestones of the depth interval 29.4– 29.59 m. The palynoassemblage S2 is established from the coaly dark clays that occurred at the depth interval 29.64–33.25 m. All palynoassemblages are dominated by Lycospora pusilla. Based on both the presence Cingulizonaes bialatus, Triquitrites comptus, (index-species of the CBd palynozone) and the occurrence of the Late Visean species Tripartites vetustus, Triquitrites marginatus, Schulzospora campyloptera, Calyptosporites arenaceousthe age of the palynoassemblages is defined as transitional Aleksinian-Mikhaylovian. The results well corresponded with data of miospore zonal scheme for Carboniferous of Russian Platform (Makhlina 1993). Paleoecological interpretation of the obtained palynoassemblages has been carrying out. General model of the paleoecological analysis is explained by the connection between the Carboniferous miospore taxa and their parent plants. Natural affinity of the miospores is determined by the comparison of dispersed material with the in situspore findings that are elucidated in paleobotanical articles (more detail see Balme 1995, Orlova et al. 2014). In concordance with the comparison of the dispersed spores and insitudata, the miospore genera of the palynoassemblages have been subdivided into six paleobotanical patterns: arborescent lycopsids (Lycospora-producing plants), subarborescent lycopsids were produced the “densospores” (Densosporites,Vallatisporites, Cingulizonates), spores of ferns (Leiotriletes, Punctatisporites, Granulatisporites, Cyclogranisporites, Knoxisporites, Raistrikia, Tripartites, Triquitrites, Acanthotriletes, Convolutispora), miospores (prepollen) of seed ferns (Schulzospora, Remysporites, Geminospora, Rotaspora), spores of the sphenopsids (pars Calamospora) and pattern of unknown natural affinity (Diatomozonotriletes, Camarozonotriletes, Iugisporis, Simozonotriletes,Waltzi spora, Calyptosporites). Abovementioned paleobotanical patterns are generalized into three paleoecological units: forest mire (arborescent and sub-arborescent lycopsids), non-forest mire (ferns, seed ferns and sphenopsids) and problematic one (unknown natural affinity). Accordingly, palynoassemblage S1 is dominated by arborescent lycopsids (66%). Sub-arborescent lycopsids (11%) and ferns (13%) were quite common in the plant communities. The seed ferns elements (2%) and sphenopsids (3%) were rare in the local palaeoflora. On the one side the forest-mire related miospores were increased upward the sequence (from 70% up to 88%), on the other side the percentage of the non-forest mire elements (from 26% up to 8%) were constant decreased in the same direction. The high percentage of forest mire unit is largely due to short predominance of the sub-arborescent lycopsids (21%). Palynoassemblage S2 is differed from the preceding one by the increased role of the arborescent lycopsids (75%) in the plant communities. The percentage of the sub-arborescent lycopsids (2%) is distinctive low. Content of the ferns (11%) is slightly decreased versus the previous palynoassemblage. Ratio of the sphenopsids (5%) and seed ferns (3%) is easily enlarged. Forest mire vegetation type was constantly dominated (75%) in the plant cover of the studied locality while the nonforest one (19%) was less common than the same from the palynoassemblage S1. The percentage of the ferns (from 3% up to 21%) and sphenopsids (from 3% up to 7%) is gradually increased during the deposition time of the palynoassemblage S2. As result of the paleoecological interpretation of the palynoassemblage the change of the vegetation types during Late Visean time has been recorded. Generally content of the forest mire related miospores is decreased upward the section while the percentage of the non forest mire elements is constantly increased. Most probably that short prevalence of the sub-arborescent lycopsids at the uppermost part of the palynoassemblage S1 can be related with initial transgression phase. From the one side this proposal is well corresponded with data of the Habib & Groth (1967) referred that Lycospora-producing arborescent lycopsids were more sensitive for higher salinity during the sea onlap and it could replaced by the stress-tolerant Densospores-producing subarbo-rescent lycopsids. From the other side the upper-most part of the palynoassemblage S1 determined from the stigmarian limestone that indicated the brackish condition. Besides the high percentage and diversity of the fern derived miospores coincides with the high portion of clastic material in deposits. It is explained by that the fern preferred open and opportunistic condition of sand bars. Apparently, the plant cover change is very similar to the same vegetation type’s ratio was marked by the previous researches in the Upper Visean localities from the Kaluga and Tula regions (Mamontov et al. 2012).

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Palynostratigraphy of the Upper Visean deposits from the Mstikhino quarry of the Kaluga region, Russia

Mamontov D. A., Orlova O. A.

Geology, Geophysics and Environment

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2012

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Vol. 38, no. 4

503--504

EN

The Mstikhino quarry is located 8 km to the north-west of the Kaluga town in the south wing of Moscow syneclise. Twelve palynological samples from the Upper Visean deposits have been collected. Updated technique of the palynological preparation was employed using hydrofluoric and hydrochloric acids to dissolve silicates and carbonates. Then the ultrasonic effect and sifting were applied for the samples. The abundant and well-preserved miospores were obtained from the bluish-grey clays of the lower part of the second quarry bank (layer No. 12). One palynoassemblage MS-6 was established. 61 species were recognized. The palynoassemblage is generally composed of the significant miospore species of the Triquitrites comptus - Cingulizonates bialatus distinctus (CBd) Zone of the Aleksinian regional stage: Lycospora pusilla (Ibrahim) Somers (60%), Schulzospora campyloptera (Waltz) Hoffmeister, Staplin et Malloy (8%), S. conforma (Kedo et Jushko) N. Umnova (4%), Cingulizonates bialatus (Waltz) Smith et Butterworth (5%), Tripartites vetustus Schemel (3%), and Triquitrites comptus Wilson (3%). It is so unusual to find high diversity of the scarce species such as Auroraspora granulata (Kedo) Oshurkova, A. micromanifesta (Hacqubard) Richardson, A. rugosiuscula (Kedo) Byvscheva, A. granulatipunctata (Hoffmeister, Staplin et Malloy) Turnau, Leiotriletes inermis (Waltz) Ischenko, L. suintortus (Waltz) Ischenko, Leiotriletes ornatus Ischenko, L. gulaferus Potonie et Kremp, Trachytriletes commodus Ischenko, T. subintortus Ischenko, Cyclogranisporites punctulatus (Waltz) Luber, C. aureus (Loose) Potonie et Kremp, Granulatisporites granulatus Ibrahim, G. granosus (Ischenko) Oshurkova, G. microgranifer Ibrahim, G. minutus Potonie et Kremp, G. pennatus (Kedo) Mamontov comb, nov, Procoronaspora rara (Palyford) Oshurkova, Iugisporis subintortus (Kedo) Mamontov comb, nov., /. pennatus (Ischenko) Oshurkova, Raistrikia macrura (Luber) Luber, R. clavata Hacquebard, Reticulatisporites cancellatus (Waltz) Playford, Convolutispora jugosa Smith et Butterworth, C. ampla Hoffmeister, Staplin et Malloy, Tripartites incisotrilobus (Naumova) Potonie et Kremp, Triquitrites trivalvis (Waltz) Potonie et Kremp, Diatomozonotriletes trilinearis Playford, Vallatisporites dictyopterus (Waltz) Byvscheva et N. Umnova in the palynoassemblage. An additional point to emphasize is that the association of rare species is not similar to those from the adjacent sections of the Kaluga Region. According to occurrence of the significant species of CBd Zone the age of the studied palynoassemblage is assigned to the Aleksinian age. The results well correspond with the data of previous palynological research. Besides the palynoassemblage MS-6 is compared to the palynoassemblages of Tripartites vetustus - Rotaspora fracta (VF) Zone of Western Europe by the cooccurrence of significant miospores of Tripartites vetustus, Triquitrites marginatus Hoffmeister, Staplin et Malloy, Remysporites magnificus (Horst) Butterworth et Williams and Knoxisporites stephanephorus Love. According to Kmiecik (1986) the presence of Murospora aurita (Waltz) Playford, Calyptosporites arenaceus (Neves et Owens) Oshurkova, Schukospora campyloptera, Tripartites incisotrilobus (Naumova) Potonie et Kremp and Reticulatisporites cancellatus (Waltz) Playford within studied miospore association confirm the correlation of the MS-6 palynoassemblage with the similar ones of the upper part of Diatomozonotriletes saetosus (Ds) Zone of Poland miospore zonation. Most probably that high miospore diversity of the studied palynoassemblage is related to various palaeoecological structures of the terrestrial parent vegetation.