Summary Sets of virtual poles corresponding to sets of geomagnetic field values at equidistant points, lying along circles of latitude, were defined on the basis of the 1980 IGRF extending to degree and order 8. Certain places on the Earth's surface yield virtual poles lying very close together. The segments of the virtual pole paths, corresponding to these places, have a large curvature. The mentioned places of the Earth's surface are supposed to be areas with a low rate of the westward drift. They form continuous zones that show a certain relation to global-tectonics features.
uum ¶rt; 8- n¶rt;a ¶rt;a¶rt; aaumu n 1980 u u nmu uma n, mmmu nm uu n ma, a u¶rt;umam ¶rt; naa m ma nmu nua¶rt;am uma n, m uu ¶rt; ¶rt;. amu u, mmmu mu ma, um uu. ¶rt;naam, m nm ma nmu m amu, m m ana¶rt; ¶rt;a ua. u am n na, m naam a m uua mmuu.
Sixteen foraminiferid assemblages have been studied from the London Clay succession at Lower Swanwick brickyard. These are divided into three faunules which are interpreted as indicating a shallow shelf regime with strong deltaic influences. 相似文献
A method for comparative estimation of reliability in detection of gravity anomaly sources in indicated fragments of studied geological space is given. The possibility of creation of this estimation is connected with disparate ideas on different peculiarities of the structure of studied geological space and noise characteristics in observed fields. The model example and results of practical problem solution are viewed. 相似文献
A thick (200 m) rock salt mass covering Late Archean granitoids was exposed for the first time in the Early Proterozoic volcanogenic-sedimentary
formations in the Onega trough of the east Baltic Shield by the Onega parametric well. The mineral composition of salts, their
geochemical features, and the isotopic composition of carbonate carbon and oxygen have been studied. After fluid inclusions
present in salts, their metamorphism temperature and isotopic composition of helium and argon were determined. The obtained
results give evidence of the fact that rock salts and magnesites associated with them were formed in an evaporate basin with
participation of deep crustal processes. The age of the underlying granitoids (2.716 ± 9 Ma) is determined using the Pb—Pb
method. 相似文献
The results of multicolor photometric and polarization observations of the blazar 4C 38.41 (Q 1633+382) performed at St. Petersburg State University, the Pulkovo Astronomical Observatory of the Russian Academy of Sciences, Boston University, and Steward Observatory in 2006–2017 are analyzed. Separate variable sources responsible for the observed activity are distinguished, whose power-lawspectra and high degree of polarization confirm their synchrotron nature. The observed color variability of the object (redder when brighter) can be explained by an increase in the contribution to the total emission of a red component with variable flux and a constant relative spectral energy distribution. A close correlation between the optical and gamma-ray light curves is identified, suggesting the same location of the variable sources responsible for the radiation in these bands.
It was found as a result of detailed study of ferromanganese stromatolites that columnar formations, i.e., fossilized stratified bacterial tufts with rhythmically alternating layers of glycocalyx, accumulations of filamentous bacteria, and lens-shaped two-layered (alternation of homogeneous microlayers with porous ones containing filamentous bacteria trichomes) packages, serve as the basis for stromatolite buildup. 相似文献
The melting curve of corundum is calculated by using two approaches: the first one is conventional and the second one is two-phase
molecular dynamics method both utilizing the same pairwise interatomic potential developed earlier on. The melting curve obtained
by the two-phase simulation method is in agreement with the existing experimental data up to 25 GPa. A comparison of melting
curves obtained by a two-phase simulation method and a conventional molecular dynamic method in NPT ensemble demonstrates
a substantial overestimation of melting temperatures when applying conventional molecular dynamic technique. The inaccuracy
of the conventional method increases with increasing pressure and, in the case of corundum, changes from about 300 K at 1
bar to about 1000 K at 1 Mbar.
Received: 25 November 1996 / Revised, accepted: 11 March 1997 相似文献