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New data on the continental deposits from the Cao Bang Basin (Cao Bang-Tien Yen Fault Zone, NE Vietnam) - biostratigraphy, provenance and faciespattern

Wysocka A., Pha D. P., Durska E., Czarniecka U., Thang D. V., Filipek A., Cuong N. Q., Tuan D. M., Huyen N. X., Tha H.V.

Acta Geologica Polonica

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2018

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Vol. 68, no. 4

689--709

EN

The Cao Bang Basin is the northernmost of the basins related to the Cao Bang-Tien Yen Fault Zone in northern Vietnam. The basin is filled with a thick series of continental deposits. However, the exact age of the sedimentary basin infill has been under discussion for a long time. Because of new published data, the authors have decided to revisit this basin. Palynological data has allowed us to assign the Cao Bang Basin infill to the Lower Oligocene PC1 complex of the Shangcun Fm. (southern China). Among the saccate grains of gymnosperms, the domination of Cathaya and Pinus was observed, whereas angiosperms are represented by Carya, Celtis, Hammamelidaceae, Ulmus and also Pterocarya, Quercus, the Castanea–Castanopsis–Lithocarpus group, and the Loranthaceae. Among pteridophytes occur Laevigatosporites, Osmundaceae, and Pteris. The sedimentological features of the Cao Bang Basin are distinct from those of other basins from the Cao Bang-Tien Yen Fault Zone. The basin is filled with a wide variety of clastic deposits, from some of coarse-grained, alluvial-fan origin, through sandy beds of fluvial origin up to fine, organic-rich lacustrine deposits. The coarse-grained lithofacies are built of clasts derived mainly from local sources. The sandstones from the basin equally are submature or immature. They contain a lot of lithoclasts, the composition of which depends on the sample location within the basin. The potential source area is composed of older sedimentary units and of granitic rocks. The geochemical samples studied reflect the geochemical composition of silicic source rocks with only a minor contribution of basic components. The succession that fills the basin is interpreted as a typical fill for relatively long-lasting evolving half-graben or strike-slip basins. Moreover, the basin is partly occupied by a subsequent present-day sedimentary basin of Quaternary age.

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Integrated palaeontological characteristics (ammonites, ostracods, foraminifers, dinocysts) of the Berriasian deposits of central Crimea

Savelieva J., Feodorova A., Shurekova O., Arkadiev V.

Volumina Jurassica

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2014

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Vol. 12, no. 1

129--162

EN

The Berriasian deposits of the central Crimea have been studied in order to compose a composite sequence of the stage with detailed palaeontological characterization. The Berriasian includes the Bedenekyrskaya Formation (packstones), Bechku Formation (siltstones, sandstones) and Kuchkinskaya Formation (sponge packstones, clays, siltstones, and coral-algal bioherm framestones). The Jacobi, Occitanica and Boissieri zones were identified based on ammonites found in the sections. A micropalaeontological analysis determined the following: 6 foraminiferal assemblages, the Costacythere khiamii – Hechticythere belbekensis and Costacythere drushchitzi – Reticythere marfenini ostracod assemblages, and a Phoberocysta neocomica dinocyst assemblage. Palaeoecological analysis of the ostracod and foraminiferal associations indicates a moderately warm marine basin with normal salinity and shallow depths (tens of meters). Only the sponge horizon was probably deposited in a deeper-water environment.

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Two climatic oscillations during the eemian interglacial : preliminary results of multi-proxy researches of palaeolake at solniki, Ne Poland

Kupryjanowicz M., Ciszek D., Morosław-Grabowska J., Marciniak B., Niska M.

Polish Geological Institute Special Papers

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2005

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Vol. 16

53--57

EN

Lake series from the Eemian Interglacial and Early Vistulian has been discovered at Solniki in the Białystok Upland region, north-eastern Poland. Preliminary results of interdisciplinary researches (pollen, diatom, Cladocera, isotopic and magnetic susceptibility analyses) were used to illustrate the changes of the Eemian climate. At present stage of investigations, there are found signs of two abrupt climatic oscillations - first with very humid climate took place at middle part of the regional Carpinus pollen zone (E5 R PAZ), and second with cold and dry climate at middle part of the regional Pinus zone (E7 R PAZ).

PL

W Solnikach na Wysoczyźnie Białostockiej (północno-wschodnia Polska) odkryto serię osadów jeziornych reprezentujących interglacjał eemski i wczesny vistulian. Wstępne wyniki badań interdyscyplinarnych (analiza pyłkowa, okrzemkowa i Cladocera, pomiary podatności magnetycznej osadów oraz zawartości izotopów stabilnych tlenu i węgla) wykorzystano do zilustrowania zmian klimatu podczas interglacjału eemskiego. Udokumentowano dwie gwałtowne oscylacje klimatu - pierwsza z ciepłym i bardzo wilgotnym klimatem (?opady) miała miejsce w środkowej części poziomu pyłkowego E5 Carpinus, druga z klimatem suchym i bardzo zimnym - w środkowej części poziomu E7 Pinus.

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On the age of the marine Eem in northwestern Germany

Winn Kyaw, Glos Rainer, Averdieck Fritz-Rudolf, Erlenkeuser Helmut

Geologos

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2000

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Vol. 5

41--56

EN

In the last interglacial, the North Sea transgressed over large parts of the Northwest European coastal area from Holland to Denmark, with a passage forming through northern Germany to the paleo-Baltic Sea. Two core holes were drilled in these interglacial deposits in Schleswig-Holstein, North Germany: the first from the regime of the paleo-North Sea, close to the town of Dagebuell, west coast, and the second near the settlement of Krummland, east of Eckemfoerde, from the regime of the paleo-Baltic Sea. Sedimentological, paleontological, and palynological studies, along with high resolution oxygen and carbon isotope stratigraphical work, and absolute dating applying the Thorium/Uranium (Th/U) and Electron Spin Resonance (ESR) methods allowed the reconstruction of the sedimentary facies associations and depositional history of this warm period in North Germany. The absence of large isostatic adjustments rendered it possible to link the local hydrographic and climatic evidence to the global development of this interglacial. Th/U-datings of molluscan shells from the marine transgression at Dagebuell (Senescens Sand unit, 28.1 to 22.1 m b.s.l.) yielded an average of 132±1 ka (n = 4 of 5). The results from the younger units (Turritella Clay; Olander Beds; 12 measurements) and from outcrops of Eemian sediments (14 measurements from 7 localities) suffered from open-system-reactions and did not provide reliable ages. ESR-measurements gave collateral support and assigned a rough age to the upper part of the sequence at Dagebuell. Climatic classification and relative correlation of these units is based on pollen-stratigraphy. In the Krummland core, Eemian beds (26.0 to 19.7 m b.s.l.) spanned the initial terrestrial/lacustrine depositional regime to the brackish/marine environment. Palynological evidence assigned the Eemian sediments to Zone 0 (subarctic) through Zone III (warm Eem) to Stage IVa (cooler Eem), following the pollen zonation by Müller (1974). In Dagebuell, the Senescens Sand unit of Zone IIIc was followed by the Turritella Clay and Lower Olander Beds of Zone IVa/b, and ended with the Upper Olander Beds in Zone V. With reference to the global event stratigraphy of the deep-sea oxygen isotope history and the sea level rise during the penultimate interglacial, the climate optimum of the Eem is found to precede the minimum stage of the global ice sheets and likely relates to 8lsO-Stage 5.5.3. The sedimentological and paleontological characteristics of the Dagebuell depositional sequence as well as the isotope evidence indicated that the sea level continued to rise beyond the Eemian hypsithermal up to a time when climate already grew colder, as is shown by the pollen assemblage, and probably culminated in 5180-Stage 5.5.1.