High stress late Maastrichtian – early Danian palaeoenvironment in the Neuquén Basin, Argentina

During the late Maastrichtian to early Danian the Neuquén Basin of Argentina was adjacent to an active volcanic arc to the west and an extensive land area to the northeast. Mineralogical and geochemical studies of the Bajada del Jagüel in the Neuquén Basin indicate a generally warm climate with seasonal changes in humidity and an open seaway to the South Atlantic that maintained marine conditions. Biostratigraphic and quantitative foraminiferal and nannofossil analyses indicate that sediment deposition during the late Maastrichtian (zones CF4-CF2, N. frequens) occurred in relatively shallow middle neritic (100 m) depths with largely dysaerobic bottom waters (abundant low O₂ tolerant benthics) and fluctuating sea level. Calcareous nannofossils indicate a high stress marine environment dominated by Micula decussata. Planktic foraminifera mimic the post-K/T high stress environment with alternating blooms of the disaster opportunists Guembelitria and low oxygen tolerant Heterohelix groups, indicating nutrient-rich surface waters and an oxygen depleted water column. The high stress conditions were probably driven by high nutrient influx due to upwelling and terrestrial and volcanic influx. The K/T boundary is marked by an erosional surface that marks a hiatus at the base of a 15-25 cm thick volcaniclastic sandstone, which contains diverse planktic foraminiferal zone P1c assemblages and nannofossils of zone NP1b immediately above it. This indicates deposition of the sandstone occurred 500 ky after the K/T hiatus. No evidence of the Chicxulub impact or related tsunami deposition was detected.     

Shortage in the midst of plenty: Labour strategies in four Central and Eastern European cities

Labour shortage was an integral feature of the communist system of economic management and one that seemed most unlikely to persist in the face of systemic transformation. A casual examination of the unemployment rates that have emerged throughout most of Central and Eastern Europe (CEE) during the course of the past decade might suggest that this early assumption was correct. However, within the region the aggregate rate of joblessness, as well as the behaviour of national output, mask the fact that certain, major urban centres appear to have weathered well the storms caused by exposure to western markets and stringent fiscal and monetary policies. In these centres transformation has meant, to a greater or lesser degree, industrial modernisation and this begs the question of whether the human capital portfolios of the inherited labour force match up to the requirements of the new environment. This paper examines the meaning of the concept of labour shortage and presents the findings from a survey of employers in four leading cities of three major CEE economies designed to elicit if, and how, manpower requirements are being met in the present climate. The results indicate that, somewhat paradoxically, labour shortage persists in the more flexible markets of the post-communist era and that firms do not expect the situation to change radically in the near future. This revised version was published online in July 2006 with corrections to the Cover Date.     

Source parameters for the 2013–2015 earthquake sequence in Nógrád county,Hungary

Between 2013 June and 2015 January, 35 earthquakes with local magnitude M _L ranging from 1.1 to 4.2 occurred in Nógrád county, Hungary. This earthquake sequence represents above average seismic activity in the region and is the first one that was recorded by a significant number of three-component digital seismographs in the county. Using a Bayesian multiple-event location algorithm, we have estimated the hypocenters of 30 earthquakes with M _L ≥1.5. The events occurred in two small regions of a few squared kilometers: one to the east of Érsekvadkert and the other at Iliny. The uncertainty of the epicenters is about 1.5–1.7 km in the E-W direction and 1.8–2.1 km in the N-S direction at the 95 % confidence level. The estimated event depths are confined to the upper 3 km of the crust. We have successfully estimated the full moment tensors of 4 M _w ≥3.6 earthquakes using a probabilistic waveform inversion procedure. The non-double-couple components of the retrieved moment tensor solutions are statistically insignificant. The negligible amount of the isotropic component implies the tectonic nature of the investigated events. All of the analyzed earthquakes have strike-slip mechanism with either right-lateral slip on an approximately N-S striking or left-lateral movement on a roughly E-W striking nodal plane. The orientations of the obtained focal mechanisms are in good agreement with the main stress pattern published for the epicentral region. Both the P and T principal axes are horizontal, and the P axis is oriented along a NE-SW direction.     

Compartmented flow at the Bátaapáti site in Hungary

Integration of hydrogeological and geological data into a conceptual model is critical for site investigation programs, since this model is the basis for hydrogeological modeling and for engineering. In the Hungarian Radioactive Waste Disposal Investigation Program, several methods have been used to characterize the potential host rock (granite) at the Bátaapáti site for a repository for low and intermediate level radioactive waste. Hydrogeological data acquisition revealed some characteristic aspects of the site. One of the most important is the presence of extensive rock deformation zones (faults) with low hydraulic conductivity, which strongly reduce the direct hydraulic communication between adjacent blocks of rock (compartmentalization). This characteristic of the rock mass results in a mosaic-like distribution of rock compartments, each with an almost constant hydraulic head. Within the compartments, hydraulic tests have shown that transmissivity is strongly scale dependent: the larger the scale, the higher the measured transmissivity. The extensive highly transmissive zones cause very low hydraulic gradients within each block, thus the transport processes are strongly influenced by the low or average transmissivity zones and the rock matrix.     

Barremian–Danian chemostratigraphic sequences of the Cauvery Basin,India: Implications on scales of stratigraphic correlation

Chemostratigraphic concepts postulate that distinct chemozones could be recognized from rock records to help correlate geographically separated strata. Many studies have upheld this view, but were limited to classic boundaries such as Cenomanian–Turonian or Cretaceous–Tertiary. Only a few elements and isotopic compositions were made use in such studies. An attempt to recognize chemozones of Barremian–Danian strata of the Cauvery Basin, South India through whole-rock chemistry had revealed many complex signals and depositional events as expressed by bulk geochemical profiles. The signals indicate major shift in sedimentation pattern from dynamic depocenter to stable depositional conditions during Santonian. Varying sensitivities of different elements towards prevalent depositional conditions are also inferred. Trends of geochemical composition indicated domination of single depositional control all through the depositional history, basinal configuration that limited terrestrial sediment source and episodic influx of detrital materials. Presence of distinct change in whole-rock geochemistry across geochronological and lithostratigraphic boundaries is deciphered through a statistical tool ANOVA. These results demonstrate that visual delineation of chemozones in a long ranging rock record would be tenuous and has to be exercised with caution.     

Biogeographical drivers of ragweed pollen concentrations in Europe

Theoretical and Applied Climatology - The drivers of spatial variation in ragweed pollen concentrations, contributing to severe allergic rhinitis and asthma, are poorly quantified. We analysed the...     

Coupling Size-Exclusion Chromatography and ICP-MS to Investigate the Speciation of Platinum-Group Elements in Environmental Samples

The applicability of size-exclusion chromatography (SEC) coupled online with a high resolution ICP-MS (HR-ICP-MS) to investigate the speciation of the platinum-group elements (PGE), Rh, Pd and Pt, was evaluated. Experiments were carried out to determine the efficiency of different hydrophilic and hydrophobic size-exclusion gel materials to select the optimal eluent in respect of resolution, recovery, reproducibility and limit of detection. The suitability of HR-ICP-MS as a reliable detection instrument at low pg ml⁻¹ levels was investigated by examining possible mass interferences with Rh, Pd and Pt. Laboratory experiments demonstrated the interaction and capability of forming complexes of humic substances with PGE, demonstrating the potential role of these ubiquitous natural substances in the mobilisation of PGE in the environment.