Palynological characterization of Givetian-Frasnian deposits in the reference Borehole section 1-Balneologicheskaya (Southern Timan)

A succession of seven palynological assemblages characterizing the Yuzhnyi Timan, Taman, Ust-Yarega, Domanik, and Vetlosyan formations of the southern Timan is established in the Givetian-Frasnian deposits recovered by Borehole 1-Balneologicheskaya and studied in detail. Five individual zones, which are distinguished within stratigraphic range of the optivus-krestovnicovii miospore zone, can be of basic importance for a high-resolution stratigraphic subdivision of the sedimentation stage under consideration. Phytostratigraphic boundary corresponding to the Frasnian Stage base in the East European platform is substantiated in palynological aspect.     

Middle-Upper Miocene stratigraphy of the Taman Peninsula, Eastern Paratethys

The stratigraphy of the Taman Peninsula is defined using the sections at Zelensky Hill ?? Panagia, Popov Kamen, Taman and Zheleznyi Rog. The stratigraphy is constructed from distribution of mollusks, foraminifers, nannofossils, diatoms, and organic-walled phytoplankton, as well as incorporating paleomagnetic data. The occurrence of oceanic diatom species in the Middle-Upper Sarmatian, Maeotian and Lower Pontian makes a direct correlation possible between the sections studied, the Mediterranean basin and oceanic zonation. The new data on planktonic and benthic biotic groups suggests a pulsating connection of the Eastern Paratethys with the open marine basins, especially during transitional intervals within constant environments. Comprehensive studies of the Chokrakian-Kimmerian microbiota provide evidence for several levels of marine microbiotic associations that are related to short-term marine invasions. The biotic and paleomagnetic data of the Taman Peninsula sections give a more comprehensive, but sometimes a controversial picture on the Eastern Paratethys history and the nature of its relationship with the adjacent marine basins.     

Age of the Vallesian lower boundary (Continental Miocene of Europe)

The Vallesian lower boundary and “Hipparion-datum” are estimated as ranging in age from 11.2 to 10.7 Ma in Central to Western Europe and Western Asia. Judging from complete sections of Sarmatian marine sediments in the Tamanskii Peninsula and Transcaucasia with known paleomagnetic characteristics, the above dates correspond to the lower upper Sarmatian (Khersonian) of the Eastern Paratethys, although in Moldova and Ukraine the earliest hipparion remains are associated with the middle Sarmatian (Bessarabian) sediments. The normally magnetized middle Sarmatian deposits in hipparion localities of Moldova are correlative with an upper part of Chron C5An (upper boundary 11.9 Ma old) or, less likely, with Subchron C5r2n (base 11.5 Ma old). Consequently, the first occurrence of hipparions in southeastern Europe is recorded in the Middle Miocene, i.e., 0.7 m.y. (or 0.3 m.y.) earlier than the date of 11.2 Ma formerly accepted for the Vallesian lower boundary in Europe. Possible reasons for disagreements in age determination of the Vallesian base are discussed.     

Middle Sarmatian facies of the Taman Trough

The sequential accumulation of middle Sarmatian sediments in the Taman Trough in the terrigenous and carbonate settings is considered. Six facies of the shallow-water basin are identified. The first half of the middle Sarmatian was marked by the accumulation of dominant clayey sediments. The formation of small serpulid-microbial bioherms took place under relatively deep conditions (upper part of the lower sublittoral zone). The terminal middle Sarmatian was dominated by the deposition of carbonates with a wide development of bacterial-algal mats. Their formation in the upper sublittoral setting below the base level of ordinary waves was intermittently disturbed by the enhanced influx of terrigenous material and accumulation of clays, as well as by the storm-induced roiling and bioturbation.     

Palynochronology of Lower Cretaceous volcano-sedimentary succession of the Rajmahal Formation in the Rajmahal Basin, India

In the Rajmahal Basin Lower Cretaceous rocks are classified under the Rajmahal Formation. It includes a series of volcanic basalt flows and associated sedimentary intertrappean beds. Up to 15 basalt flows have been recorded in this basin. The intertrappean beds comprise sandstone, shale, siltstone, and clay deposits which are rich in spores and pollen. The palynoflora recovered from intertrappean beds shows definite pattern of evolution and diversification. On the basis of its overall composition, distribution pattern of age marker taxa and the First Appearance Datum of key taxa, four palynological assemblages have been identified. The chronology of these assemblages in ascending order is (1) Ruffordiaspora australiensis, (2) Foraminisporis wonthaggiensis, (3) Foraminisporis asymmetricus, and (4) Coptospora verrucosa. These assemblages ascertain the age of the volcano-sedimentary sequence of the Rajmahal Formation in the Rajmahal Basin as Berriasian to Aptian. The palynochronology of the intertrappean beds enables their correlation in the Rajmahal Basin. In different areas of the basin, the palynological dating of the lowermost intertrappean bed within the Rajmahal Formation which overlies the Dubrajpur Formation, has provided a Berriasian to Aptian age. The palynological assemblage indicating the Berriasian age is inferred as the time of the initiation of volcanic activity which continued up to the Aptian in the Rajmahal Basin.     

Marine carbonate systems in the Sarmatian (Middle Miocene) of the Central Paratethys: the Zsámbék Basin of Hungary

The study of eight stratigraphic sections at the margin of the semi-enclosed Zsámbék Basin (Hungary) allows the sedimentary anatomy of oolitic–bioclastic systems in the Sarmatian of the Central Paratethys to be reconstructed. The mollusc, foraminiferal and ostracod associations indicate that the carbonate systems are Latest Badenian to Late Sarmatian in age. The Lower–Upper Sarmatian deposits are organized in superimposed subaqueous dunes prograding towards the basin on a low-angle ramp. During the Late Sarmatian, the ramp underwent subaerial erosion linked to a moderate relative fall in sea-level. Lagoonal deposits were later formed and microbial–nubeculariid–bryozoan–serpulid buildups were emplaced. The 'abnormal' marine conditions of the Sarmatian, conducive to the development of a poorly diversified flora and fauna and dominant non-skeletal grains, are linked to fluctuating salinities, mesotrophic to eutrophic conditions and perhaps high alkalinity.     

Middle-upper Miocene volcanic ashes of the Kerch-Taman region

Results of the detailed study of Miocene volcanic ashes from Kerch and Taman peninsulas are presented. Based on the distribution of pyroclastics in the rocks under consideration, the Sarmatian and late Meotian stages of volcanic activity are distinguished. In close association with other geological data, results of the first microprobe analysis of the volcaniclastic materials are analyzed. It has been revealed that Sarmatian ashes are characterized by rhyolitic composition, whereas upper Meotian ashes correspond to dacites and rhyodacites. Decrease of silicate content and increase of alkalinity in the studied pyroclastic rocks are traced from ancient to younger sediments. The upper Meotian volcanics are noted for higher concentration of potassium. The predominantly vitroclastic Kerch-Taman ashes with a low content of calcium and high contents of potassium and sodium most likely belong to a single magmatic center. Stages of volcanic events and petrochemical similarity of composition of the magmatic products suggest that the studied ash material belongs to volcanic centers of the Lesser Caucasus.     

Late glacial and holocene landscapes of central Beringia

New palynological and sedimentological data from St. Lawrence Island present a rare view into late-glacial and Holocene environments of the central Bering Land Bridge. The late glaciation was a time of dynamic landscape changes in south-central Beringia, with active thermokarst processes, including the formation and drainage of thaw lakes. The presence of such a wet, unstable substrate, if widespread, probably would have had an adverse impact on food sources and mobility for many of the large mammal populations. The establishment of Betula shrub tundra on the island suggests late-glacial summers that were warmer than present, consistent with regional paleoclimatic interpretations. However, the increasing proximity to the Bering Sea, as postglacial sea levels rose, modified the intensity of warming and prevented the establishment of deciduous forest as found in other areas of Beringia at this time. The mid- to late Holocene is marked by more stable land surfaces and development of Sphagnum and Cyperaceae peat deposits. The accumulation of organic deposits, decline of shrub Betula, and decrease in thermokarst disturbance suggest that conditions were cooler than the previous. A recent decline in peat accumulation at the study sites may relate to local geomorphology, but similar decreases have been noted for other arctic regions.     

华北地块东北缘红庙子盆地鹰嘴砬子组孢粉化石

报道华北地块东北缘地区红庙子盆地鹰嘴砬子组的孢粉化石,建立了Cicatricosisporites-Abietineaepollenites-Piceites组合,该组合的主要特征为:以裸子类双气囊花粉和海金沙科孢子为主,含一定量裸子类无气囊花粉,未见被子类花粉,孢粉组合特征可与松辽盆地沙河子组对比。一些具有早白垩世时代意义的孢粉化石,如Cicatricosisporites sp.,Cicatricosisporites undulates和Cicatricosisporites implexus的出现,表明鹰嘴砬子组的地质时代为早白垩世。根据孢粉化石资料,推测华北地块东北缘地区在鹰嘴砬子组沉积时期古植被面貌以松科和杉科组成的松柏类针叶林为主,林下生长着真蕨类。古气候相当于湿润-半湿润的亚热带气候。     

High-resolution stratigraphy of the Upper Jurassic section(Laptev Sea coast)

Jurassic strata are widespread through Arctic Siberia and host oil and gas fields. However, in most cases, the geology of such vast areas still remains unexplored, and study of the Jurassic stratigraphy and reconstructions of geologic history are possible only through analysis of sediment cores. In this connection, there is a clear need for detailed studies of microfaunas (foraminifera, ostracods) and palynomorphs (dinocysts, spores, and pollen). The studied reference section of the Upper Jurassic and Lower Cretaceous is located on the left side of Anabar Bay of the Laptev Sea (Nordvik Peninsula, Cape Urdyuk-Khaya). An uninterrupted and continuous section from the Upper Oxfordian to the Lower Valanginian is exposed in coastal cliffs and consists mainly of silty clay deposits with abundant macro- and microfossils. Integrated field studies (biostratigraphy, lithostratigraphy, sedimentology) allow a more detailed characterization of the regional geologic framework. A detailed subdivision of the section is based on the systematic composition of ammonites from Upper Oxfordian and Kimmeridgian deposits. Several foraminiferal zones of the Upper Oxfordian and Lower Volgian are defined, and some of them are denfined for the first time. The distribution of ostracods in the section is analyzed for the first time. The section is also studied using palynological analysis, that results in its detailed subdivision on palynological data and recognition of two sequences of palynostratigraphic units. The integrated stratigraphy is used to establish the precise position of stage and substage boundaries. The continuity of the section is defined based on micropaleontological and palynological data.     

Liptinite in coal and oil source rocks in northern Thailand

Palynological study of northern Thailand coal and oil deposits indicates a similar palynological association to that of the Borneo region. Coal petrographic studies of these deposits show variations in the liptinite macerals, especially alginite types. The oldest of these coal and oil deposits, which are of Late Oligocene to Early Miocene age, are dominated by Botryococcus sp. or Botryococcus-related algae. Thick-walled lamaginites and spores and pollen of temperate affinity, are found in some areas. By contrast, thin-walled lamaginite is dominant in late Middle Miocene time. Resinite, suberinite, and cutinite are dominant in forest swamp coal deposits whereas alginite, cutinite and lycopodium spores are dominant in lacustrine environments. Exsudatinite is common even at early levels of maturation. These liptinite macerals can be major sources of oil and gas.     

内蒙古扎兰屯地区龙江组孢粉组合及其地质意义

成吉思汗驿站龙江组剖面位于扎兰屯成吉思汗镇东南部,组内大化石稀少,但孢粉化石丰富,下部岩性为沉凝灰岩、凝灰岩、凝灰质砂岩、砂岩、砾岩,上部岩性为安山岩、英安岩。通过对成吉思汗驿站龙江组孢粉化石的分析,在龙江组中识别出圆形粒面孢-二连粉孢粉组合带(Cyclogranisporites-Erlianpollis)。通过对孢粉化石属种的分析,根据具有时代指示意义的孢粉化石,如Erlianpollis,Cicatricosisporites,Pilosisporites等,认为成吉思汗地区龙江组孢粉化石形成时代为早白垩世,结合地质、古植物及孢粉化石的定量分析,认为龙江组植被类型反映亚热带气候,指示温暖潮湿的环境。     

Patterns of the Distribution of Rare-Earth Elements in Waters of Mud Volcanoes

Doklady Earth Sciences - The original data on the distribution of rare-earth elements in waters of mud volcanoes of Sakhalin Island, Taman Peninsula, and Azerbaijan are presented. It has been shown...     

An Early Cretaceous age for the Rajmahal traps, Panagarh area, West Bengal: palynological evidence

The discovery of traps in the subsurface Mesozoic succession of the Panagarh area, West Bengal, has drawn attention to their correlation with the traps in the Rajmahal Basin, Bihar. The objective of this paper is to assess the palynological dating of the intertrappean beds with the help of sequential first appearances of the stratigraphically important spore species Cicatricosisporites australiensis, Aquitriradites spinulosus, and Foraminisporis wonthaggiensis. C. australiensis, along with the first appearance of A. spinulosus, denotes the earliest Berriasian. This association is significant for recognition of the Jurassic/Cretaceous boundary. The lowest occurrence of F. wonthaggiensis indicates deposits of Berriasian–Valanginian age. The data on which these observations are based have been obtained from the intertrappean beds of the Rajmahal Formation in six boreholes: PGD-1A, 2, 4, 6, 8 and 9A. Further palynological studies on boreholes PGD-4, 8 and 9A have indicated the approximate time-span for the duration of volcanic activity in the Panagarh area. This seems to have been initiated in the early Berriasian and continued into the Hauterivian, which is earlier than the volcanism associated with the Rajmahal traps in the Rajmahal Basin.     

Çakraz Formation, Çamdağ area,NW Turkey: early/mid‐Permian age,Rotliegend (Germany) and Southern Alps (Italy) equivalent—a stratigraphic re‐assessment via palynological long‐distance correlation

The palynological record from the Permian part of the Çakraz Formation from the Çamdağ area of NW Turkey has been investigated in order to obtain a more precise age assessment than achieved in previous studies. The ‘Late Permian’ age and a possible age range beginning in the Roadian (mid Permian) were discussed before for sections of palynomorph‐bearing strata occurring within the formation. These deposits are now assigned to the late Cisuralian/Guadalupian and considered to be not older than early Kungurian, and not younger than Capitanian. The new age assessment was conducted via a long‐distance, intercontinental palynostratigraphic correlation from NW Turkey to South America, where results of radiometric datings were linked to some siliciclastic sections by absolute ages to the chronostratigraphy. Common conspicuous taxa in pollen‐dominated assemblages from both regions are Lueckisporites and Vittatina such as Lueckisporites virkkiae, L. latisaccus, L. stenotaeniatus, Vittatina corrugata, V. subsaccata and V. wodehousei. These species co‐occur in strata of the northern as well as southern palaeohemisphere settings (NW Turkey and S America). Thus, Lueckisporites latisaccus, L. stenotaeniatus and Vittatina corrugata are, as well as L. virkkiae or V. subsaccata, considered as being cosmopolitan. Due to the more precise palynological dating of part of the Çakraz Formation and surrounding deposits they are here broadly correlated with Permian continental successions from the Southern Alps, Italy, including the Val Daone Conglomerate and the Verrucano Lombardo/Val Gardena Sandstone (Gröden) red beds, and the Rotliegend deposits of Germany. These results support some earlier views regarding the age and stratigraphic equivalences with European deposits. The new age for the Çakraz Formation also supports recent considerations as middle Permian (part Guadalupian), and as Cisuralian for the lower parts of the formation, such as the fossil‐bearing section with plants and tetrapod traces further east in NW Turkey, where the unit also crops out. Copyright © 2014 John Wiley & Sons, Ltd.     

Tectonic evolution of the Intra-Pontide suture zone in the Armutlu Peninsula, NW Turkey

The Armutlu Peninsula and adjacent areas in NW Turkey play a critical role in tectonic reconstructions of the southern margin of Eurasia in NW Turkey. This region includes an inferred Intra-Pontide oceanic basin that rifted from Eurasia in Early Mesozoic time and closed by Late Cretaceous time. The Armutlu Peninsula is divisible into two metamorphic units. The first, the Armutlu Metamorphics, comprises a ?Precambrian high-grade metamorphic basement, unconformably overlain by a ?Palaeozoic low-grade, mixed siliciclastic/carbonate/volcanogenic succession, including bimodal volcanics of inferred extensional origin, with a possibly inherited subduction signature. The second unit, the low-grade znik Metamorphics, is interpreted as a Triassic rift infilled with terrigenous, calcareous and volcanogenic lithologies, including basalts of within-plate type. The Triassic rift was unconformably overlain by a subsiding Jurassic–Late Cretaceous (Cenomanian) passive margin including siliciclastic/carbonate turbidites, radiolarian cherts and manganese deposits. The margin later collapsed to form a flexural foredeep associated with the emplacement of ophiolitic rocks in Turonian time. Geochemical evidence from meta-basalt blocks within ophiolite-derived melange suggests a supra-subduction zone origin for the ophiolite. The above major tectonic units of the Armutlu Peninsula were sealed by a Maastrichtian unconformity. Comparative evidence comes from the separate Almacık Flake further east.Considering alternatives, it is concluded that a Mesozoic Intra-Pontide oceanic basin separated Eurasia from a Sakarya microcontinent, with a wider Northern Neotethys to the south. Lateral displacement of exotic terranes along the south-Eurasian continental margin probably also played a role, e.g. during Late Cretaceous suturing, in addition to overthrusting.     

Quaternary palynology of the Pacific slope of Washington

Quaternary deposits on the Pacific slope of Washington range in age from the earliest known interglaciation, the Alderton, through the Holocene. Pollen stratigraphy of these deposits is represented by 12 major pollen zones and is ostensibly continuous through Zone 8 over more than 47,000 radiocarbon yr. Before this, the stratigraphy is discontinuous and the chronology less certain. Environments over the time span of the deposits are reconstructed by the comparison of fossil and modern pollen assemblages and the use of relevant meteorological data. The Alderton Interglaciation is characterized by forests of Douglas fir (Pseudotsuga menziesii), alder (Alnus), and fir (Abies). During the next younger interglaciation, the Puyallup, forests were mostly of pine, apparently lodgepole (Pinus contorta), except midway in the interval when fir, western hemlock (Tsuga heterophylla), and Douglas fir temporarily replaced much of the pine. Vegetation outside the limits of Salmon Springs ice (>47,00034,000 yr BP) varied chiefly between park tundra and forests of western hemlock, spruce (Picea), and pine. The Salmon Springs nonglacial interval at the type locality records early park tundra followed by forests of pine and of fir. During the Olympia Interglaciation (34,00028,000 yr BP), pine invaded the Puget Lowland, whereas western hemlock and spruce became manifest on the Olympic Peninsula. Park tundra was widespread during the Fraser Glaciation (28,00010,000 yr BP) with pine becoming more important from about 15,000 to 10,000 yr BP. Holocene vegetation consisted first of open communities of Douglas fir and alder; later, closed forests succeeded, formed principally of western hemlock on the Olympic Peninsula and of western hemlock and Douglas fir in the Puget Lowland. Over the length of the reconstructed environmental record, climate shifted between cool and humid or relatively warm, semihumid forest types and cold, relatively dry tundra or park tundra types. During times of glaciation, average July temperatures are estimated to have been at least 7°C lower than today. Only during the Alderton Interglaciation and during the Holocene were temperatures higher for protracted periods that at present.     

Synchronous deposition of massive sulphide deposits in the Iberian Pyrite Belt: New data from Las Herrerías and La Torerera ore-bodies

Two small to medium sized massive sulphide deposits, Las Herrerías and La Torerera, located in the Iberian Pyrite Belt (IPB) are examined from a geological and palynostratigraphic perspective. The palynological assemblages are assignable to the Retispora lepidophyta–Verrucosisporites nitidus (LN) miospore Biozone (Latest Devonian: Latest Famennian/Strunian) of Western Europe. This age permits correlation with some of the main massive sulphide deposits dated so far in the region (viz., Tharsis, Aznalcóllar, Sotiel-Coronada or Neves-Corvo), and validates once again the hypothesis that a single mineralizing event was responsible for the genesis of most of the IPB’s massive sulphide deposits. The present study confirms that palynostratigraphy is an invaluable high-resolution biostratigraphic tool in the IPB, applicable to dating, correlation and ore-exploration.     

Strontium and oxygen isotopic systems in waters of mud volcanoes of the Taman Peninsula

Ten of eleven analyzed water samples from mud volcanoes of the Taman Peninsula are characterized by ⁸⁷Sr/⁸⁶Sr ratio within 0.70734–0.70957, which overlaps the values typical of the Mesozoic and Cenozoic sedimentary carbonates, but sharply differs from the value in the clayey sediments of the Maikop Group (0.7157 ± 0.0022). These data indicate that the strontium isotopic composition is mainly defined by carbonate reservoirs, with relatively little effect of elision solutions, input of which is noticeable only in the water of Gladkovsky Volcano (⁸⁷Sr/⁸⁶Sr = 0.71076). The high δ¹⁸O in mud volcanic waters (up to 14.2‰) can also be attributed to ionic exchange with sedimentary carbonates at temperatures around 150°C.     

Middle to late Miocene sequence stratigraphy of the Transylvanian Basin (Romania)

The history of Middle to Late Miocene evolution of the Transylvanian Basin was determined by the bordering Carpathian orogen evolution, the tectonic events being well recorded by the sedimentary history. The basin evolved in a back-arc setting, under a regional, compressional stress field. The major tectonic events produced during the Late Sarmatian and Post-Pannonian were related to the reactivation of the pre-Badenian fault systems. The Transylvanian Basin got uplifted after the Late Pannonian (? during the Pliocene), and at least 500 m of sedimentary cover was eroded.

Based on seismic and well-log interpretation, core and outcrop sedimentology, and microfauna, eight sequences were defined. The early Middle Miocene sequences are roughly synchronous to five 3rd order global sea-level cycles. Most of the recognized sequence boundaries are enhanced by regional tectonic events. The sedimentary evolution was also strongly influenced by salt-tectonics, active starting with the Late Sarmatian.

Two sequences were identified in the Lower Badenian deposits. The third sequence (late Early Badenian to early Mid Badenian) preserves information about deeper shelf settings. The lowstand of the following sequence was responsible for the deposition of the salt formation (late Mid Badenian), an important lithostratigraphic marker in the sedimentary record of the basin. In general, the Upper Badenian deposits (parts of the 4th and 5th sequences) belong to deep marine submarine fan systems. The Sarmatian (partially 5th, 6th and partially 7th sequences) was characterized by diverse salinity conditions, stretching from brackish to hypersaline, and by high tectonic instability, which induced several significant relative sea-level falls. During that time, deltaic (north) and fandeltaic (east) systems fed submarine fans, stacked between salt-related submarine heights (“channeled” deep-marine depocenters). Most of the Pannonian deposits (partially 7th and 8th sequences) belong to submarine fan systems, but shallower facies were also found in the western and eastern part of the basin.