On stilpnomelane in some Romanian Carpathian crystalline formations

Summary The stilpnomelane minerals in the epimetamorphic series of the Romanian Carpathians are divided into four genetic groups. Some ferrostilpnomelanes from metamorphic iron-, manganese- and sulfide-ores have been studied optically, chemically, by differential thermal analysis, thermogravimetric analysis, X-ray diffraction, and IR absorption spectroscopy. Several conclusions on the chemical constitution and the widespread occurence of ferrostilpnomelane in the metamorphic ores of the Carpathians are given.

---

Über Stilpnomelan in einigen kristallinen Formationen in den rumänischen Karpaten

Zusammenfassung Die Stilpnomelanvorkommen aus dem epimetamorphen Kristallin der rumänischen Karpaten werden in vier genetische Gruppen eingeteilt. Einige aus metamorphosierten Eisen-, Mangan- und Sulfiderzen stammende Ferrostilpnomelane wurden optisch, chemisch, mit Differentialthermoanalyse, Thermogravimetrie, Röntgenbeugung und Ultrarot-Absorptionsspektroskopie untersucht. Als Schlußfolgerungen ergeben sich einige allgemeine Hinweise über die Zusammensetzung des Ferrostilpnomelans in den Kristallinerzen der Karpaten.

---

---

Mit 5 Figures     

Charakterisierung des chemischen Zustandes der Limmat zwischen Zürichsee und Wettingen (1974–1978)

In connection with the enlargement and updating of the Werdhölzli sewage treatment plant, research was undertaken on the chemistry of that part of the River Limmat lying between Lake Zürich and Wettingen from 1974 to 1978. The extensive amount of data involved was subjected to statistical analysis and the results are being interpreted. In general, the chemical condition of the water of the Limmat river upstream from the Werdhölzli sewage plant can be described as good. In order to attain the desired water quality criteria downstream of the waste-water outfall of the plant, pollution in therms of ammonium nitrogen and organic substances must be reduced. The performing of a chemical pre-precipitation process has brought about a sizable reduction in the phosphorus concentration of the Limmat river downstream of the plant; the values are now below the required water quality limits.     

Geometry of isograds in metamorphic terrains

A simple mathematical relation among the dip of isograd surface (θ), dip of isotherm surface (α), temperature gradient (T_g), pressure gradient (P_g) and δT/gdP of reaction is given by:

Full-size image (1K)

P_g is taken to be constant at 0.3 kb/km. Four major theoretical models for shapes and orientations of isograds are formulated on the basis of the parameters α, T_g and δT/δP. This offers a rational basis for studying the geometry of isograds, normal/reverse metamorphism and determination of temperature gradient. Two examples have been studied in the light of these models; in one case the domed shape of the isograd is best explained by a downwardly directed T_g; in the other case, reverse metamorphism is best explained as the result of a horizontal T_g of 18°C/km.     

The parent bodies of CR chondrites and their secondary history

Renazzo-type (CR) chondrites are a relatively rare group of carbonaceous chondrites with the vast majority having escaped thermal alteration. This means that CRs are composed of relatively unprocessed material, depending on the extent of aqueous alteration they have experienced. Hydration in CRs ranges from incipient alteration of matrix glass, up to nearly complete replacement of the rock by hydration products. The extent of secondary processes is often difficult to assess in these meteorites, due to their heterogeneity and diversity of alteration products. Yet, this is crucial in order to understand the extent of geological processing that occurred on the primary parent body. Additionally, the parent asteroids of CRs remain a mystery, mainly because terrestrial oxyhydroxide signatures dominate the reflectance spectra of CRs. In this work, we have conducted optical and IR reflectance and transmission spectra of 25 CR chondrites in order to (i) better evaluate the extent of aqueous alteration that occurred on the CR parent body, and (ii) find possible parent body candidates. Terrestrial oxyhydroxides were removed from 12 samples, as these tend to interfere with the optical-IR spectra of CRs. Our results suggest, among other, that (i) aqueous alteration in most of our CRs was limited to the matrix and (ii) most CRs may stem from a continuum of X-to-C complex asteroids, depending on their extent of aqueous alteration. More specifically, the endmembers being Xk/Xn types and Cgh/Ch types. This has strong implication in regard to what we can expect from the Psyche mission.     

New VLBI2010 scheduling strategies and implications on the terrestrial reference frames

In connection with the work for the next generation VLBI2010 Global Observing System (VGOS) of the International VLBI Service for Geodesy and Astrometry, a new scheduling package (Vie_Sched) has been developed at the Vienna University of Technology as a part of the Vienna VLBI Software. In addition to the classical station-based approach it is equipped with a new scheduling strategy based on the radio sources to be observed. We introduce different configurations of source-based scheduling options and investigate the implications on present and future VLBI2010 geodetic schedules. By comparison to existing VLBI schedules of the continuous campaign CONT11, we find that the source-based approach with two sources has a performance similar to the station-based approach in terms of number of observations, sky coverage, and geodetic parameters. For an artificial 16 station VLBI2010 network, the source-based approach with four sources provides an improved distribution of source observations on the celestial sphere. Monte Carlo simulations yield slightly better repeatabilities of station coordinates with the source-based approach with two sources or four sources than the classical strategy. The new VLBI scheduling software with its alternative scheduling strategy offers a promising option with respect to applications of the VGOS.     

Potential pollution risk in natural environment of golf courses: an example from Rusovce (Slovakia)

The objective of the article presented herein is to highlight the specific issue of the protection of water sources in the vicinity of golf courses. Currently we have experienced the construction of a large number of golf courses, which are often found in areas where the protection of natural groundwater resources is needed. In this article, limit conditions are specified, which could be used in construction of other golf courses in the world, where there is a potential threat of contamination of groundwater resources. The issue is demonstrated on a case study in the area of a water resource, Rusovce. A major concern of golf courses is the fact that in an apparently clean environment of these anthropogenic structures contamination occurs, resulting from the maintenance, and the current legislation does not address this specific group of areas. These are particularly dangerous substances derived from fertilizer and turf protection, in particular the use of pesticides (insecticides, herbicides, fungicides, acaricides, e.g. nematocides, and related products, such as growth regulators used for plant protection). The results of the modelling at the water source, Rusovce, show that the combination of negative factors (for example, the groundwater table level close to the surface along with extremely high precipitation totals or the areas flooding and the lack of a golf course bedrock sealing) the limit value of 0.100 μg/l of pesticides concentration in groundwater was exceeded up to 0.880 μg/l. Similarly, such excess may occur in the case of an emergency situation (for example, the spilling of the barrel with the pesticide), where the concentration of pesticides in groundwater may be increased up to 0.874 μg/l in standard conditions (without flooding with an average depth of groundwater table level beneath the terrain). But even under a standard level of security for the establishment and operation of a golf course and standard procedures for the maintenance of the lawn, the concentration of pesticides in the wells reached 0.0001 μg/l.     

Effects of a candidate antifouling compound (medetomidine) on pheromone induced mate search in the amphipod Corophium volutator

Environmental hazards associated with traditional, toxic antifouling coatings based on heavy metals calls for the development of alternative, environmentally acceptable antifouling compounds. Medetomidine ((±)-4-[1-(2,3-dimethylphenyl)ethyl]-1H-imidazole) is a candidate antifouling biocide which impedes settlement of barnacles in the nanomolar range. Prior to introducing novel biocides it is of great importance to consider potential effects on non-target organisms. This study is the first to investigate the effects of medetomidine on the amphipod Corophium volutator, specifically effects on male mate search behaviour. In a laboratory, Y-maze bioassay, C. volutator males were allowed to follow female pheromones after 24 h exposure to 0 (control), 0.01 and 0.1 μg mL⁻¹ medetomidine. We found that exposure to medetomidine at both concentrations significantly reduced pheromone induced mate search (by 42–71%), with fewer males crawling towards female odour. The results obtained indicate that medetomidine may impair the reproductive fitness of non-target crustaceans, an aspect that needs to be considered before further commercialisation.     

The subsurface megascopic characteristics of basalt and basement rocks from Koyna-Warna area of Maharashtra,India

Vertical deep boreholes of depth up to 1522.50m have been drilled in Koyna-Warna area of Maharashtra State within the Deccan Volcanic Province to study the most outstanding example of Reservoir Triggered Seismicity (RTS). The drilling of 9 bore-holes in the area has provided a window to earth scientists to peep into geological details available below Deccan Trap.The 932.50m thick pile of Deccan basalt, consisting of 30 flows at Rasati, near Koyna, which has been physically seen through cores, present a marvellous geological repository for observations. The megascopic characteristics of various flows and variation in composition have been presented in this paper. The microscopic and geochemical characteristics have been kept out of this communication, as the relevant studies are not completed to draw any conclusion. This study records the presence of granite wash (≈1m thick) over basement and below basalt representing Late Archaean to Cretaceous period hiatus. The basement rocks, presumably of Late Archaean age have been described mega-scopically. A fair picture of sub-surface pre-Deccan topography is shown with the help of borehole data, which confirm the nearly flat topography of pre-Deccan surface especially in this part of the area occupied by 30 flows of Deccan basalt. Correlation of 30 flows with the established stratigraphy has also been attempted for subsurface existence of Ambenali (Upper) and Poladpur Formations of Wai Subgroup in Koyna-Warna area.