Regionally metamorphosed greisens of the Moldanubicum     

D. Němec  J. Páša 《Mineralium Deposita》1986,21(1):12-21

The orthogneiss bodies of the Moldanubicum in the western part of the Bohemian-Moravian Heights (eskomoravská vrchovina) are apoleucogranites, presumably of Precambrian age and probably of anatectic origin. Most orthogneiss bodies have been shown to contain greisens transformed by regional metamorphism. The greisens have maintained their identity during regional metamorphism below higher almandine-amphibolite facies grade, i.e. over the stability field of muscovite. Massive quartz (metamorphosed vein quartz) is frequent, and mineralization is associated with it in a few localities. Greisens in orthogneisses may serve as evidence of magmatic origin.  相似文献   

Spectral theory of electromagnetic induction in a radially and laterally inhomogeneous earth     

Karel Pěč  Zdeněk Martinec  Reviewer V. Petr 《Studia Geophysica et Geodaetica》1986,30(4):345-355

Summary The partial differential equations of electromagnetic induction in a 3-D Earth of inhomogeneous conductivity are reduced to a system of ordinary differential equations of the 2nd order for the spectral coefficients of the field.

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au am nu¶rt; ¶rt; maum u¶rt;uu u m ¶rt;¶rt; n n¶rt;umu n¶rt; um ¶rt;uua au m n¶rt;a ¶rt; nma uum n.

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Fault interaction and seismicity: Laboratory investigation and its seismotectonic interpretation   总被引：2，自引：0，他引：2  

A. piák  T. Lokajíek 《Pure and Applied Geophysics》1986,124(4-5):857-874

Systems of two parallel linear faults of the same length with the angle of inclination =45° were investigated under uniaxial linearly increasing load. Perspex plates were used as models. For each treated fault configuration the morphology of tensile cracks and the sequence of seismoacoustic events of shear and tensile origin were studied.It is shown that the seismic regime of a fault system is strongly influenced by the contact conditions on a fault plane; it is different in the faults with the aseismic contact, represented by open slits, and in the faults with the seismoactive contact, represented by filled slits, respectively.The experiments proved the dominating role of a fast shear displacement of the stick-slip type in the regime of seismic energy release of a fault system. The tensile crack generation seems to be only of little—if not negligible—importance. On the other hand, the existence of tensile cracks in a fault system can play an important role in the course of subsequent loading cycles because the stick-slip displacements can take place not only along the primary faults but also along the planes of tensile cracks.A comparison of some results of model experiments and the already published results of geological and seismological investigations indicated that the way of seismic energy relase on faults in nature and in the laboratory could be of the same character. Several analogies between the seismic regime of a fault model and of real seismic regions were found concerning the morphology of faults, off-fault fore- and aftershocks, and earthquake doublets, respectively.  相似文献   

Spherical harmonic analysis and Fourier transformation     

Jaromír Bordovský  Reviewer Z. Nádeník 《Studia Geophysica et Geodaetica》1986,30(1):13-27

Summary The paper deals with the computation of spherical harmonic coefficients from surface measurements of the magnetic or gravity field of the Earth when the measurements are distributed regularly. The Fourier representation of associated Legendre functions which this procedure makes use of, then enables the harmonic analysis to be transformed to Fourier analysis which has better numerical properties.

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ama na ama uu uu uum n nm uu aum uuaumau n u a, ¶rt;a mu uu an ammu ma. ¶rt;mau n a¶rt; , m unm mm n¶rt;¶rt;, nm nmauu aau naam aau , m a¶rt;am uu uumu mau.

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The relation between the heat flow field and the distribution ofP n -wave velocities for the European continent     

Jaroslav Kubík  Reviewer A. Janáčková 《Studia Geophysica et Geodaetica》1986,30(1):60-78

Summary The dependence of P_n-wave velocities on the heat flow, temperature at the crustmantle boundary and the thickness of the Earth's crust in Europe was investigated in relation to the problem of lateral inhomogeneities in the upper mantle. A map was constructed of the distribution of P_n-wave velocities on the territory of Europe. The relations these investigations yielded, were compared with the results of laboratory experiments and all the results are discussed from the physical point of view. The conclusion drawn is that that temperature and pressure effect provide a sufficient explanation of the observed regional changes of P_n-wave velocities for the European continent.

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auum ¶rt;auu mu n¶rt; ¶rt; nmu uua (P_n) u mn nm, mnam a nmu amuu u m a mumuu n a u¶rt;aa u numa ¶rt;¶rt;m amuu. mumuu n a maa a uu m P_n- a nmu uua. u¶rt;u umam ¶rt;a mama aam u¶rt;au uuu m n¶rt; amuu u u ¶rt;au u mnam mmmm mama n¶rt;aa am. ¶rt;a ¶rt;, m ua uu m P_n- a n mum ¶rt;mam um uuu mnam u ¶rt;au a nmu uua.

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Anomalous induction across Europe   总被引：1，自引：0，他引：1  

Oldřich Praus  Jana Pěčová 《Studia Geophysica et Geodaetica》1995,39(3):286-288

Summary Using real induction vector data, collected at 958 European observation sites, together with our data from the Bohemian Massif and the West Carpathians, we have generated a contour map of the transfer function TF1 (corresponding to transfer function A in Wiese's relation). Only the zero contour is retained and shown on the map. It clearly marks the main anomalous induction zones, related to internal structural inhomogeneities, across Europe.  相似文献   

Seismically active fracture zones and distribution of thermal springs in Ecuador     

Václav Hanuš  Jiří Vaněk  Gaston Sandoval  Reviewer J. Zahradník 《Studia Geophysica et Geodaetica》1987,31(3):258-265

Summary The analysis of the geometry of distribution of earthquake foci occurring in the continental South American plate above the subducted Nazca plate reveals that in the region of Ecuador these earthquakes accumulate in 8 well-separated fracture zones. These zones are interpreted as a system of deep seismically active fractures induced in the continental plate by the process of subduction. It is shown that the position of known thermal springs and of observed hydrothermal alterations in Ecuador correlates with the outcrops of the fracture zones.

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¶rt;aumuu an¶rt;u a mu muma num uu a¶rt; ¶rt;uu a¶rt; naa m mu mu anm 8 m¶rt; a a, m umnmua au uu amu a a muma um n ¶rt;uu. aam, m nmu um ma umuu uu¶rt;ma uu a¶rt; a¶rt;am ¶rt;a mu a .

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Deep structure of the bohemian massif from phase velocities of Rayleigh and Love waves     

Erhard Wielandt  Andreas Sigg  Axel Plešinger  Josef Horálek  Reviewer K. Pěč 《Studia Geophysica et Geodaetica》1987,31(1):1-7

Summary Phase velocities of Rayleigh and Love waves have been measured between the broadband seismic stations KHC (Kaperské Hory, South Bohemia) and KSP (Ksi, Lower Silesia), a profile that nearly coincides with the Interactional DSS Profile VII. The data for both wave types were separately inverted into models of shear-wave velocity versus depth. Novotný's model KHKS 82[1] for the DSS Profile VII was used as a start model. While the crustal section of Novotný's model is compatible with both of our data sets, our Rayleigh-wave data require smaller shear-wave velocities, on the average by 0.24 km/s, in the top 180 km of the mantle. The average difference between Novotný's model and our Love-wave model in that depth range is only 0.06 km/s. If our identification of the observed Love waves as the fundamental mode is correct, this result indicates the presence of polarization anisotropy in the uppermost mantle.

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u a mu u a ¶rt; unu uuu mauu (an , a u) u S (, ua uu). u - S nuuum mmmm ¶rt;a¶rt; nu VII . a ¶rt; u mun m¶rt; umua ¶rt;u auumu mu nn mu. am mam¶rt;u a unaa ¶rt; S 82 m[1] ¶rt; nu VII . a am ¶rt;u m aua uu aau au ¶rt;a, ¶rt;a au ¶rt;a ¶rt; mm uu m nn — ¶rt; a 0,24 / 180 uma amuu. ¶rt;a aua ¶rt; ¶rt; m u a ¶rt; ¶rt; a m ¶rt;uanau n¶rt;mam 0,06 /. u aa u¶rt;muuau a¶rt;a a a ¶rt;ama ¶rt;a m nau, m mm mam u¶rt;ummm numuu nuau aumnuu amuu.

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On global short-periodic synchronous oscillations of the atmosphere     

Vojtěch Vítek  Reviewer J. Bednář 《Studia Geophysica et Geodaetica》1987,31(3):324-326

Summary The existence of global synchronous atmospheric oscillations with the period of about 1.4 hour is indicated in terms of a simple theoretical model of the circumpolar circulation.

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u nu nm mmu ¶rt;u un uuu naa maua au am nu¶rt; 1,4 .

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Deep seismically active fracture zones in ecuador and northern peru     

Václav Hanuš  Jiří Vaněk  Reviewer J. Zahradník 《Studia Geophysica et Geodaetica》1987,31(1):8-25

Summary A system of 8 seismically active fracture zones was delineated on the basis of the distribution of earthquake foci in the continental lithosphere of Ecuador. The position and width of the outcrop, thickness, dip and maximum depth of the individual fracture zones were estimated and correlated with surface geological and tectonic phenomena, volcanism and hydrothermal manifestations. The existence and strike of the fracture zones was independently confirmed by the occurrence of historical disastrous earthquakes.

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uma 8 uu amu a a aa a auu an¶rt;u a mu muma um a¶rt;a. u n¶rt; nu u uua a nmu, mua, u auaaua m¶rt; a . mau mu auu n¶rt;m¶rt;am a¶rt;u umuu aum mu u nmau nmu, mmu, au uu¶rt;mau nuu.

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Visiting professors at Instituto Geofísico and Facultad de Geología, Minas y Petróleos, Escuela Politécnica Nacional, Quito (Ecuador).  相似文献