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61.
T. M. Will 《Mineralogy and Petrology》2001,72(1-3):229-247
Summary Geometric data of fault planes and fault plane lineations, together with the observed sense of shear on the slip planes,
were used to calculate paleostress tensors and fields responsible for the post metamorphic peak D3 and D4 deformation events
in the four Odenwald units sensu Krohe (1991). The paleostress fields were calculated using the method of Will and Powell (1991). As inferred from the paleostress analysis, the D3 strike-slip deformation west of the Otzberg fault zone was caused
by a, ± N-S directed, compressional regional stress field, with shallowly plunging σ1 axes and σ3 directions that plunge at shallow to moderate angles to the E or W; the calculated mean orientations are: σ1 06 → 350, σ2 77 → 234 and σ3 12 → 085. The B?llsteiner Odenwald east of the Otzberg fault zone was not affected by this stress field. This implies that
the Bergstr?sser and B?llsteiner Odenwald were spatially separated and formed independent crustal blocks during D3. The D4
faulting event is recognised in all areas investigated, even though most prominently in units III and IV, and juxtaposed the
Bergstr?sser and B?llsteiner Odenwald. This faulting episode was caused by a paleostress field with a steeply westerly plunging
σ1 axis and a shallowly southsoutheasterly plunging σ3 axis. The orientations of the principal stresses are: σ1 52 → 270, σ2 38 → 085 and σ3 06 → 174. With continued deformation from D3 to D4, there was a progressive change in the orientation of the stress field
indicating a change from a N-S compressional to extensional stress field, accompanied by the progressive development of strike-slip
faults and late normal faults. Paleostress field orientations in the Pfalz Forest, SW of the Odenwald, determined by Fl?ttmann and Oncken (1992) are very similar to those obtained for the Odenwald region and indicate a regionally consistent stress pattern in
the southwestern part of the Mid-German Crystalline Rise (MGCR) during strike-slip and normal faulting deformations.
Received July 8, 1999; revised version accepted March 28, 2000 相似文献
Zusammenfassung Paleostress-Tensor Analyse sp?ter Deformationsereignisse im Odenwald-Kristallin und ein Vergleich mit anderen Einheiten der Mitteldeutschen Kristallinzone, Deutschland Für die vier Odenwald-Einheiten im Sinne von Krohe (1991) wurden Pal?ostressfelder für die Blattverschiebungs- und Abschiebungsereignisse D3 und D4 mit der Methode von Will und Powell (1991) berechnet. Die Analyse ergibt, da? das regionale Spannungsfeld, das westlich der Otzberg-Zone im Bergstr?sser Odenwald zum D3-Ereignis führte, ein ± N-S gerichtetes kompressives Stresssfeld war. Die σ1-Achse f?llt flach nach N bzw. S ein, die σ3-Achse mit kleinen bis moderaten Winkeln nach E bzw. W; die berechneten Orientierungen der Hauptspannungsrichtungen sind: σ1 08 → 350, σ2 77 → 234 and σ3 12 → 085. Der B?llsteiner Odenwald, ?stlich der Otzberg-Zone, wurde von diesem Spannungsfeld nicht erfa?t. Dies impliziert, da? Bergstr?sser und B?llsteiner Odenwald w?hrend des D3-Ereignisses voneinander getrennt waren und separate Krusteneinheiten darstellten. Auswirkungen der D4-Deformation k?nnen im gesamten Untersuchungsgebiet erkannt werden, am st?rksten jedoch in den Einheiten III und IV. Dieses Ereignis wurde von einem Pal?ostressfeld mit einer steil nach W einfallenden σ1- und einer flach nach SSE einfallenden σ3-Achse verursacht und führte zum Zusammenschlu? von Bergstr?sser und B?llsteiner Odenwald. Die berechneten Orientierungen der Hauptspannungsrichtungen sind: σ1 52 → 270, σ2 38 → 085 und σ3 06 → 174. Die Rotation der Hauptspannungsrichtungen war mit einer ?nderung von einem kompressionalen N-S gerichteten (D3) hin zu einem extensionalen (D4) Stressfeld verbunden. Die erzielten Ergebnisse sind sehr ?hnlich mit Resultaten, die Fl?ttmann und Oncken (1992) im Pf?lzer Wald ermittelten. Dies weist auf ein regional übereinstimmendes Spannungsfeld im SW-Teil der Mitteldeutschen Kristallinzone hin.
Received July 8, 1999; revised version accepted March 28, 2000 相似文献
62.
From elements formed in interstellar furnaces to humans peering back at the stars, the evolution of life has been a long, intricate and perhaps inevitable process. Life as we know it requires a planet orbiting a star at just the right distance so that water can exist in liquid form. It needs a rich supply of chemicals and energy sources. On Earth, the combination of chemistry and energy generated molecules that evolved ways of replicating themselves and of passing information from one generation to the next. Thus, the thread of life began. This chart traces the thread, maintained by DNA molecules for much of its history, as it weaves its way through the primitive oceans, gaining strength and diversity along the way. Organisms eventually moved onto the land, where advanced forms, including humans, ultimately arose. Finally, assisted by a technology of its own making, life has reached back out into space to understand its own origins, to expand into new realms, and to seek other living threads in the cosmos. 相似文献
63.
Rapid variations of the radial velocities of absorption components of Ti II lines in CH Cyg are presented. The periods of these variations are determined to 1.89 and 41.07 days in 1982. The variations are interpreted through oscilliations in the mass transfer from the M component onto the accretion disk of the companion during periastron passage.Paper presented at the IAU Colloquium No. 93 on Cataclysmic Variables. Recent Multi-Frequency Observations and Theoretical Developments, held at Dr. Remeis-Sternwarte Bamberg, F.R.G., 16–19 June, 1986. 相似文献
64.
We integrated numerically, in the frame of the four body problem Sun-Jupiter-Saturn-asteroid the orbit of the asteroid 1974 MA, an Earth-crosser, which is located in a region where three resonances overlap: the two secular resonances
5 and
16 and the mean motion resonance 5/1. The numerical integration yields a qualitative orbital evolution of this particular region. 相似文献
65.
66.
We have obtained velocity-resolved spectra of the 12C II 157.8 microns 2P3/2-2P1/2 fine structure line in the M42 region of Orion. Observations at 0.8 km s-1 resolution with a laser heterodyne spectrometer show multiple velocity components in some locations, with typical linewidths of 3-5 km s-1. Spectra of theta 1C and BN-KL also show weak emission from the F = 2-1 hyperfine component of the equivalent 13C II line. From the observed 12C II/13C II line intensity ratios, we deduce that the 12C II emission is optically thick with tau approximately 5 at both positions. Excitation temperatures of 128 K and 90 K, together with column densities of approximately 1 x 10(19) cm-2 and approximately 4 x 10(18) cm-2, are derived for theta 1C and BN-KL, respectively. 相似文献
67.
S. Yabushita K. Wada T. Takai T. Inagaki D. Young E. T. Arakawa 《Astrophysics and Space Science》1986,124(2):377-388
The microorganism model of interstellar grains is investigated by spectroscopy from the infrared (IR), visible to the ultraviolet (UV) wave regions.E. coli, yeast and spores ofBacillus subtilis exhibit absorption bands at =3.1 and 9.7 m; they also exhibit several absorptions at 68 m which are in agreement with the observed IS extinction curves.To obtain the extinction curves in the visible and UV regions, dry films of microorganism are prepared on a MgF2 plate or synthesized quartz plate and their spectra measured. In the wavelength region 190400 nm, conventional spectrophotometers are adopted for the measurement. The extinction curve of the film ofE. coli is similar to the observed IS curve.For the wave-range 100<<400 nm, a vacuum UV spectrometer is adopted to avoid absorptions due to O2 in the atmosphere. The extinction spectra by this method are in agreement with the result obtained by the conventional method where comparison is possible. The extinction curves ofE. coli and yeast are such that they incrase towards the short wavelength and exhibit a peak at -190 nm, which is different from the well-known IS peak at =220 nm. It remains to be seen whether interstellar low temperatures (1040 K) can shift the peak position in the extinction curve of biochemical materials. 相似文献
68.
T. Landscheidt 《Solar physics》1986,107(1):195-199
The Blackman-Tukey power spectrum of flare generated X-ray bursts X1 observed from 1970 to 1982 by satellite instrumentation (SOLRAD/SMS/GOES) shows prominent peaks at 156, 4.8, 2.8, and 1.1 months. According to a statistical test of the significance of the deviation of these peaks from Markov red noise, the peaks at 2.8 and 1.1 months are significant at the 99% confidence level while the peak at 4.8 months reaches the 95% level. A replication by means of the maximum entropy spectral analysis (MEM) yields the same prominent peaks at the same frequencies. 相似文献
69.
Parameters of the distant galaxy clusters of 3C295 (z=0.46) and Cl 0024+1654 (z=0.39) are compared with the predictions made using galaxies of the local clusters Coma (z=0.023) and DC 0329–52 (z=0.057) taking theK-effect into account. The distributions of colour and morphological type, and the amplitudesF
+/F– of the 0 4000 discontinuity are examined and no evidence for evolution of the galaxies and the clusters can be seen. 相似文献
70.
H. A. Taylor Jr. P. A. Cloutier M. Dryer S. T. Suess A. Barnes R. S. Wolff 《Earth, Moon, and Planets》1985,32(3):275-290
Corotating solar wind streams emanating from stable coronal structures provide an unique opportunity to compare the response of planetary ionospheres to the energy conveyed in the streams. For recurrent solar conditions the signal propagating outward along spiral paths in interplanetary space can at times exhibit rather similar content at quite different downstream locations in the ecliptic plane. Using solar wind measurements from plasma detectors on ISEE-3, Pioneer Venus Orbiter (PVO) and Helios-A, as well as in-situ ion composition measurements from Bennett Ion Mass Spectrometers on the Atmosphere Explorer-E and PVO spacecraft, corotating stream interactions are examined at Earth and Venus. During May–July 1979 a sequence of distinct, recurrent coronal regions developed at the Sun. Analysis of these regions and the associated solar wind characteristics indicates a corrresponding sequence of corotating streams, identifiable over wide distances. The time series of solar wind velocity variations observed at Earth, Venus, and the Helios-A positions during June–July attests to intervals of corotating stream propagation. The characteristics of the stream which passed Earth on July 3, are observed at Helios-A and at Venus (PVO) about 8 days later, consistent with the spiral path propagation delay times between the locations in the ecliptic plane. On July 3, Earth and Venus have a wide azimuthal separation of about 142 . Although the planetary environments are distinctly different, pronounced and somewhat analagous ionospheric responses to the stream passage are observed at both Earth and Venus. The response to the intercepted stream is consistent with independent investigations which have shown that the variability of the solar wind momentum flux is an important factor in the solar wind-ionosphere interaction at both planets. 相似文献