Planktonic Foraminiferal Biostratigraphy of the Upper Cretaceous of the Central European Basin

Planktonic foraminifera are one of the most stratigraphically important groups of organisms for the Cretaceous system. However, standard foraminiferal zonations based mostly on species from the Tethyan bioprovince are hardly applicable in temperate regions where warm-water taxa are scarce or lacking. We propose a foraminiferal zonation based on foraminiferal events recognized in the northern Foraminiferal Transitional Bioprovince, which likely has a high correlation potential at least at a regional scale. Fifteen planktonic foraminiferal zones are distinguished from the upper Albian up to the uppermost Maastrichtian strata in extra-Carpathian Poland and western Ukraine. From the bottom to the top, Thalmanninella appenninica, Th. globotruncanoides, Th. reicheli, Rotalipora cushmani, Whiteinella archaeocretacea, Helvetoglobotruncana helvetica, Marginotruncana coronata, M. sinuosa, Pseudotextularia nuttalli, Globotruncana linneiana, G. arca, Contusotruncana plummerae, Rugoglobigerina pennyi, Globotruncanella petaloidea and Guembelitria cretacea. These zones are calibrated by macrofaunal zonations.

BIOSTRATIGRAPHIC SIGNIFICANCE OF OSTRACODS FROM THE UPPER DEVONIAN OF THE NORTHWESTERN KUZNETSK BASIN (TOM RIVER, SOUTH EAST OF WEST SIBERIA)

New data on ostracods from three Upper Devonian key sections located in the northwestern part of the Kuznetsk Basin along the Tom River have been obtained. Biostratigraphic analysis allowed define biostratons identified in the rank of Beds with ostracods (Bairdia vassinoensis, Hollinella valentinae and Acratia (cooperina) granuliformis). Beds with ostracods are of different correlation potential. Thus, Beds with Bairdia vassinoensis and Beds with Hollinella valentinae can be traced in two structural-facies subzones of the Kuznetsk Basin margin. Forms with a wide geographical distribution have been established in the ostracod complexes. They could be regarded as markers for interregional correlations.

Systematic investigation of magnetic, optical and transport properties of RTX (R = Rareearth, T = 3d/4d and X = p−block elements) for thermoelectric applications

The half-Heusler compounds have been extensively studied because of their exceptional transport properties. We have explored rare earth (RE)-based half-Heusler bismuthides compounds, [Formula: see text]PdBi ([Formula: see text][Formula: see text]=[Formula: see text]Gd, Dy and Ho) with the cubic crystal structure. Structural, magnetic, optical and transport properties are investigated using PBE-GG approximations by solving exchange-correlation potential. Electronic properties including spin-polarized band structure and density of states verified that semimetals with half-filled [Formula: see text]-orbitals across the Fermi-level are useful for thermoelectric applications. Magnetic properties reveal that values of the total spin magnetic moment are in close agreement with the experimental data. Optical properties with spin–orbit coupling (SOC) have a higher absorption coefficient and comparatively lesser energy loss which shows that studied materials are appropriate for optoelectronic devices. Moreover, transport properties including electrical and thermal conductivities, Seebeck coefficient, specific heat, power factor and figure of merit have been discussed in detail. The consistency of our results with the literature reveals that SOC plays a vital role in the transport properties of the materials.

Elastic Scattering of Electron and Positron by Radium and Radon Atoms

The Differential Cross Sections (DCS's), Total Cross Sections (TCS's) and Momentum Transfer Cross Sections (MTCS's) of electron and positron scattering by radium and radon atoms were calculated in the range of energy (5–500) eV using a total potential consisting of combining the static, exchange and polarization potentials at long distances. In addition, the correlation potential of Perdew–Zunger at short distances for electrons was used, as well as the correlation potential of Jain for positrons. The exchange potential for positrons was neglected. In this study, a good agreement with other experimental values and theoretical values of many investigators was found.

Triassic palynoevents in the circum-Arctic region

Triassic successions of the present-day Arctic contain abundant and diverse assemblages of nonmarine palynomorphs that have provided important biostratigraphic information. Dinoflagellate cyst are biostratigraphically useful in marine intervals in the Upper Triassic. Based on published records, we present a compilation of 78 last occurrences (LOs), first occurrences (FOs), and some abundance events that are anticipated to have correlation potential in the Arctic region. Palynological work has been carried out in many Arctic areas, with extensive palynological research published on the Triassic successions of the Norwegian Barents Sea and Svalbard. An updated, recent palynological zonation scheme exists for that region, integrating previous schemes and illustrating the chronostratigraphic value of palynology in the Triassic. For the Lower and Middle Triassic, good ammonoid control ties the palynological zones to the chronostratigraphic scale. Independent control is sparse, and resolution is lower in the Upper Triassic, so that palynology is commonly the only biostratigraphic discipline available for chronostratigraphic dating and correlation.