Metasomatic rocks with greisenization associated with the ore-bearing zones in the Iron Mountains (Železné hory Mountains,eastern Bohemia,Czechoslovakia)

In the central Iron Mountains the ore-mineralized deformation zones represent deep reaching faults which possibly reach the upper mantle. During geological history they were used by ascending magmas, fluids, and barren and ore hydrothermal solutions. It can be shown that the metasomatism provoked by acid fluids bears the character of greisenization. The type of the original greisenized rocks here can be determined on the basis of elements that were immobile during greisenization, especially Si, Ti, Sc and REE. After or even during greisenization, the metasomatic rocks were affected by shearing metamorphism corresponding in its PT conditions to the middle zone of the almandine-amphibolite facies. It was possibly in this period that the enigmatic skarn body of Samaov originated. Owing to its similarity to the dyke skarn of Kraskov, its similar origin could be assumed: the deposition of skarn minerals from circulating fluids, which were perhaps released during greisenization.     

Relation between macroseismic intensity and instrumental parameters of strong motions — A statistical approach

One hundred and twenty-eight strong ground motion CALTECH (Earthquakes in the U.S.A., 1940–1971) records of five Californian earthquakes, recorded at ground level and in basements, for which the modified Mercalli macroseismic intensities are known, were statistically processed to calculate 165 wave parameters. Correlation of the peak values of particle acceleration, velocity and displacement, energy, impulse and root-mean-square amplitude of the vibrations, durations of vibrations for certain levels of the peak amplitude, and spectral energies of 10 frequency windows with macroseismic intensity are discussed from the viewpoint of classification of ground-motion records.Paper presented at the 21st General Assembly of the European Seismological Commission held in Sofia 1988.     

X-ray bright surges

We present evidence of X-ray emission from surges that are bright in H. These surges have many features common to flaring arches of Martin and vestka (1988); the basic difference between the two is that in flaring arches cold and hot plasma are injected into clearly defined closed magnetic loops, while in the surges the injection goes into large-scale magnetic field structures of which the second footpoint is usually unknown. Because of the steep density gradient in such large-scale structures, the X-ray visibility of bright surges is limited to a few tens of seconds only. A series of repetitive surges, some of them bright and emitting X-rays, occurred on 8 July, 1980 from footpoints of two large-scale coronal structures, which might have been the legs of an enormous arch at least 600 Mm long.     

On the possibility of luminescence emission of interstellar grains

The possible occurrence of luminescence emission by different irradiated materials in interstellar space is discussed. It is shown by means of a model computation that the quantum efficiency of luminescence emission is high enough and can, in general, be detected in interstellar space. Further, it is argued that the wavelength-dependent intensity increase observed in the NGC 7023 reflection nebula at the distance of 3.4 from the illuminating star can be explained by luminescence emission of UV irradiated and Cu or rare-earth-doped glassy particles.     

Method of locating the Pc 1 source and hot plasma parameters in the generation region

A method of estimating hot and cold plasma parameters using ground Pc 1 observations is proposed. The values of both hot and cold plasma concentrations, proton energy and temperature anisotropy in the Pc 1 generation region are calculated. It is shown that the most appropriate (effective) indicator of the L-shell, where Pc 1 are generated, is the group delay of wave packets.     

Coronal Mass Ejection of 15 May 2001: I. Evolution of Morphological Features of the Eruption

We study the initiation and development of the limb coronal mass ejection (CME) of 15 May 2001, utilizing observations from Mauna Loa Solar Observatory (MLSO), the Solar and Heliospheric Observatory (SOHO), and Yohkoh. The pre-eruption images in various spectral channels show a quiescent prominence imbedded in the coronal void, being overlaid by the coronal arch. After the onset of rapid acceleration, this three-element structure preserved its integrity and appeared in the MLSO MK-IV coronagraph field of view as the three-part CME structure (the frontal rim, the cavity, and the prominence) and continued its motion through the field of view of the SOHO/LASCO coronagraphs up to 30 solar radii. Such observational coverage allows us to measure the relative kinematics of the three-part structure from the very beginning up to the late phases of the eruption. The leading edge and the prominence accelerated simultaneously: the rapid acceleration of the frontal rim and the prominence started at approximately the same time, the prominence perhaps being slightly delayed (4 – 6 min). The leading edge achieved the maximum acceleration a_max 600 ± 150 m s^–2 at a heliocentric distance 2.4 –2.5 solar radii, whereas the prominence reached a_max 380± 50 m s^–2, almost simultaneously with the leading edge. Such a distinct synchronization of different parts of the CME provides clear evidence that the entire magnetic arcade, including the prominence, erupts as an entity, showing a kind of self-similar expansion. The CME attained a maximum velocity of v_max 1200 km s^–1 at approximately the same time as the peak of the associated soft X-ray flare. Beyond about 10 solar radii, the leading edge of the CME started to decelerate at a–20 m s^–2, most likely due to the aerodynamic drag. The deceleration of the prominence was delayed for 10 –30 min, which is attributed to its larger inertia.     

Impact of Air Pollution on Genetic Material of Shallot (Allium cepa L. var. ascalonicum) Exposed at Differently Polluted Sites in Slovenia

Test shallot plants Allium cepa L. var. ascalonicum were exposed to field conditions at six research plots in the most polluted areas in Slovenia in the vegetation seasons in 1999 and 2000. The intention of this research was to evaluate the influence of air pollution on mitotic activity and frequency of chromosomal aberrations in meristematic tissues of root tips of bioindication plants. Significant differences in the mitotic index and in frequency of chromosomal aberrations at different sampling plots in pot experiments were found and the correlation between the ozone concentration and the mitotic index was determined. The results showed the presence of cytotoxic substances at chosen sampling sites, which caused the decrease of mitotic cell division and the presence of genotoxic substances, which resulted in the increase of frequency of chromosomal aberrations.     

Synoptic Situations and Pollutant Concentrations in Fog Water Samples from the Milešovka Mt.

This contribution presents the results of chemical analyses of the fog and/or cloud water samples, which were collected at the Mileovka Mt. during the years 2000 and 2001. The study aims mainly at proving the dependence of pollutant concentration on the direction of the atmospheric steering flow. It is evident that the highest mean pollutant concentration in fog water appeared at the steering flow from south or at the flow with an east component. The lowest pollutant concentrations were reported during the synoptic situations with considerable west component of the steering flow. Furthermore, we compare the characteristic values of pollutant concentrations from the Mileovka Mt. with similar results from other sites abroad.     

Correlations between statistical population indices and spectral characteristics of carbon stars

The coefficients of correlation between spectroscopic data published by Yamashita (1967) and others for carbon stars and the statistical population indices calculated for these stars at the Toru Observatory are calculated (Table II). The intensity estimates of Cai 4227 Å, Nai D lines, the C¹³/C¹² ratio, then=n(Li/Ca) index, as well as CN and probably C₂ bands are higher in population I carbon stars. The CH(G) band and probably hydrogen (H, H, H) lines as well as Baii 4554 and 4934 Å lines are stronger in population II carbon stars. The photoelectric colour indices, corrected for interstellar reddening do not show significant population effects. They can be used as spectral type equivalents. For a population criterion the CH/CN intensity ratio is proposed.