Beiträge zur Kenntnis der Lagerstätten dichten Magnesits. I. Mitteilung. Der Tremolitdunit Yom Galgenberg bei Zobten

Ohne ZusammenfassungAbgeschlossen iiim Juni 1947.     

Electrostatic radiation of plasma in the upper ionosphere in the inhomogeneous geomagnetic field

It has been indicated that the spectrum of electrostatic waves in the ionospheric plasma depends on the geophysical conditions and solar wind parameters. The wave field measurements in the frequency band 0.1–10 MHz in the topside ionosphere were used to analyze the electrostatic instabilities of the plasma electron content (the APEX satellite experiment). A change of the sign of one magnetic field component at the geomagnetic equator can result in the formation of the large-scale irregular plasma structure with a decay of the natural electrostatic oscillations and vortices in unstable plasma. The plasma particle polarization drift from the region of decay of electrostatic oscillations and vortices can cause large plasma density and temperature gradients across the geomagnetic field. New vortices can originate at these gradients. This mechanism of plasma vortex formation and decay can be important for mass and energy convection in the topside ionosphere.     

Sensitivity analysis of a no-crossflow model for the transient flowmeter test

 Logarithmic sensitivities and plausible relative errors are studied in a simple no-crossflow model of a transient flowmeter test (TFMT). This model is identical to the model of a constant-rate pumping test conducted on a fully penetrating well with wellbore storage, surrounded by a thick skin zone, and situated in a homogeneous confined aquifer. The sensitivities of wellbore drawdown and wellface flowrate to aquifer and skin parameters are independent of the pumping rate. However, the plausible relative errors in the aquifer and skin parameters estimated from drawdown and wellface flowrate data can be proportionally decreased by increasing the pumping rate. The plausible relative errors vary by many orders of magnitude from the beginning of the TFMT. The practically important flowrate and drawdown measurements in this test, for which the plausible relative errors vary by less than one order of magnitude from the minimum plausible relative errors, can begin approximately when the dimensionless wellface flowrate exceeds q _D =q/Q≈0.4. During most of this stage of the test, the plausible relative errors in aquifer hydraulic conductivity (K _a ) are generally an order of magnitude smaller than those in aquifer specific storativity. The plausible relative errors in the skin hydraulic conductivity (K _s ) are generally larger than the plausible relative errors in the aquifer specific storativity when the thick skin is normal (K _s >K _a ) and smaller when the thick skin is damaged (K _s <K _a ). The specific storativity of the skin zone would be so biased that one should not even attempt to estimate it from the TFMT. We acknowledge Wiebe H. van der Molen for recommending the De Hoog algorithm and sharing his code. This research was partially supported by the US Geological Survey, USGS Agreement #1434-HQ-96-GR-02689 and North Carolina Water Resources Research Institute, WRRI Project #70165.     

Analysis of the 16S-23S rDNA intergenic spacers (IGSs) of marine vibrios for species-specific signature DNA sequences

Vibrios are widespread in the marine environment and a few pathogenic species are known to be commonly associated with outbreaks of diarrheal diseases in humans due to the consumption of raw or improperly cooked seafood. However, there are also many Vibrio species which are potentially pathogenic to vertebrate and invertebrate aquatic animals, and of which little is known. In an attempt to develop rapid PCR detection methods for these latter class of vibrios, we have examined the 16S-23S intergenic spacers (IGSs) of 10 lesser-known Vibrio species and successfully developed species-specific primers for eight of them--Vibrio costicola, V. diazotrophicus, V. fluvialis, V. nigripulchritudo, V. proteolyticus, V. salmonicida, V. splendidus and V. tubiashii. The IGS amplicons were amplified using primers complementary to conserved regions of the 16S and 23S rRNA genes, and cloned into plasmid vectors and sequenced. Analysis of the IGS sequences showed that 37 ribosomal RNA (rrn) operons representing seven different IGS types have been cloned from the 10 vibrios. The three IGS types--IGS(0), IGS(IA) and IGS(Glu)--were the most prevalent forms detected. Multiple alignment of representative sequences of these three IGS types from different Vibrio species revealed several domains of high sequence variability, which were used to design species-specific primers for PCR. The specificity of the primers were evaluated using total DNA prepared from different Vibrio species and bacterial genera. The results showed that the PCR method can be used to reliably detect eight of the 10 Vibrio species in marine waters in this study.     

Shock metamorphism of some rock-forming minerals

The shock metamorphism of schist consisting of garnet, biotite, quartz, and plagioclase is studied under shock wave loading of a sample in steel recovery ampoules of plane geometry. A maximum shock pressure was reached during several circulations of waves in the sample (stepwise shock compression) and varied within the range 19–52 GPa. The recovered samples were examined by the methods of scanning electron microscopy and microprobe and X-ray phase analysis. The results were compared with natural impactites and with shock-induced alterations in minerals loaded by a spherical convergent wave. It is established that, given a plane geometry of loading (stepwise shock compression), solid-state transformations at the lattice level (migration of chemical elements and formation of shock thermal aggregates) are not observed in all of the studied minerals, in contrast to natural impact processes and spherical geometry experiments. Under the conditions of our experiments, minerals melt at higher pressures than in the case of natural impact processes and spherical geometry experiments. However, for each mineral studied, the mechanical strain patterns at close shock pressures are, on the whole, the same for all of the aforementioned three variants of shock wave loading.     

Present-day seismicity of the south-eastern Elbe Fault System (NE Bohemian Massif)

The Variscan Bohemian Massif is disrupted by the NW-SE striking Elbe Fault System in its northern part. The increased tectonic activity associated with this structure is manifested by increased seismicity in the eastern part of the Sudetes. With the use of a temporary local seismic network, the total number of micro-earthquakes located in this region increased to 153 for the period 1996–2003. The local magnitudes vary between −0.6 and 1.8 and the seismic energy was often released in swarm-like sequences. Five seismic events with well-defined P-onset polarities at five or six stations enabled the estimation of focal mechanisms. The present-day activity of the WNW-ESE to NNW-SSE fault systems is discussed on the basis of source mechanisms, the alignment of the epicentres, as well as morphological and geological evidence. The majority of the recent seismic activity is concentrated in a 40–60 km wide zone of a generally NW-SE trend. This structure represents a regional zone of weakness within the SE termination of the Elbe Fault System, defined by a mesh of interconnected faults, of which many are deep-seated and highly permeable and some are associated with light to moderate historical earthquakes. Both in the areas due south and due north of this zone the present-day seismic activity is very low. The increased tectonic activity can be interpreted as a result of the abundance of suitably oriented faults and their interconnection into major fault systems, the proximity of the Outer Carpathian indentor and the Cainozoic volcanic and associated recent post-volcanic activity. The similar character of swarms and their coincidence with the post-volcanic activity in the southeastern part of the Elbe Fault System and in some focal zones of the western Bohemian seismically active area suggests that overpressurized fluids may represent a potential swarm-triggering mechanism.     

Magnetolithologic and magnetomineralogical characteristics of sediments at the Mesozoic/Cenozoic boundary: The Koshak section (Mangyshlak peninsula)

Results of a detailed petromagnetic study of sediments of the Koshak section, including the Mesozoic/Cenozoic (K/T) boundary, are presented. The rocks are shown to have a very low magnetization. A relatively high magnetization is characteristic of two thin clayey beds, one at the K/T boundary and the other 0.6 m above it: x up to 2.5 × 10^?9 m³/kg, M _s up to 0.6 × 10^?3 A m²/kg, and M _rs up to 0.4 × 10^?3 A m²/kg. This is related to relatively high concentrations of hemoilmenite (up to 0.2%), magnetite (up to 0.01%), and goethite (up to 0.24%) in these beds. It is evident that the distribution of these magnetic minerals is lithologically controlled (the predominant occurrence in clayey beds), which is expressed, in particular, in the relation between the paramagnetic (clayey) and diamagnetic (carbonate) contributions to the magnetization of the sediments. Thus, clayey interbeds are sharply distinguished by the value of the paramagnetic magnetization (M _p = (83–86) × 10^?5 A m²/kg) as compared with purely diamagnetic chalk (M _d = ?(26–35) × 10^?5 A m²/kg). Minor concentrations of metallic iron (up to ～0.002%) discovered in the sediments have a lithologically uncontrolled distribution (metallic iron is more often observed near the K/T boundary rather than in clayey beds). Most probably, magnetite, hemoilmenite, and goethite were accumulated mostly with clay and other terrigenous material, while fine particles of iron are likely to have been dispersed by air. The whole set of the data of this work suggests that the K/T boundary is not distinguished by characteristic magnetomineralogical and magnetolithologic features.     

Pattern Informatics and its Application for Optimal Forecasting of Large Earthquakes in Japan

Pattern Informatics (PI) technique can be used to detect precursory seismic activation or quiescence and make an earthquake forecast. Here we apply the PI method for optimal forecasting of large earthquakes in Japan, using the data catalogue maintained by the Japan Meteorological Agency. The PI method is tested to forecast large (magnitude m ≥ 5) earthquakes spanning the time period 1995–2004 in the Kobe region. Visual inspection and statistical testing show that the optimized PI method has forecasting skill, relative to the seismic intensity data often used as a standard null hypothesis. Moreover, we find in a retrospective forecast that the 1995 Kobe earthquake (m = 7.2) falls in a seismically anomalous area. Another approach to test the forecasting algorithm is to create a future potential map for large (m ≥ 5) earthquake events. This is illustrated using the Kobe and Tokyo regions for the forecast period 2000–2009. Based on the resulting Kobe map we point out several forecasted areas: The epicentral area of the 1995 Kobe earthquake, the Wakayama area, the Mie area, and the Aichi area. The Tokyo forecast map was created prior to the occurrence of the Oct. 23, 2004 Niigata earthquake (m = 6.8) and the principal aftershocks with 5.0 ≤ m. We find that these events were close to in a forecasted area on the Tokyo map. The PI technique for regional seismicity observation substantiates an example showing considerable promise as an intermediate-term earthquake forecasting in Japan.     

The gravitational effect of bodies with variable density

Summary Determination of the gravitational effect of some bodies, the density of which is supposed to be variable in the vertical direction, possibly in the horizontal direction, too.

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n¶rt;uaumau ma m m, nmm m um mua uu muma anau.

     

Time Trend of BHCs and DDTs in a Sedimentary Core in Macao Estuary, Southern China

BHCs and DDTs in a ²¹⁰Pb dated sedimentary core in Macao estuary were analysed with supercritical CO₂ extraction and GC-ECD. The concentrations of BHCs in the core sediment dated from 1962 ranged from trace level (相似文献