The results of petrographic, geochemical, and isotopic studies of the Neoproterozoic and Upper Paleozoic sandstones of the Eastern Taimyr complement the available data on their genesis and confirm their molassic origin. The sandstones and mudstones of the Neoproterozoic Stanovaya and Posadochnaya formations formed mostly from the erosion products of the magmatic and metamorphic complexes with ages of ~970–800 Ma and from older siliciclastic rocks. The Upper Paleozoic sandstones of the Byrranga, Sokolinaya, and Turuza formations are characterized by a somewhat lower degree of maturity. Most of them formed from erosion products of magmatic and metamorphic complexes with ages of ~500 and ~300 Ma, although sediments sourced from an older provenance were also encountered. The ages of the youngest detrital zircon grains from the Upper Paleozoic sandstones are close to the depositional ages in some cases and differ by more than 100 m.y. in other cases. This suggests that one should be cautious about using the maximum depositional ages for establishing the tectonic setting of sedimentary basin formation.

An attempt is made to compare discrimination diagrams of the first (mid-1980s) and second (early 2010s) generations compiled using data for sedimentary successions of different ages. Our results suggest that the diagrams of different generations allow more or less correct discrimination only between the platform, rift, passive margin, and island arc settings. The data for collision sediments do not form separate fields in these diagrams.

The Upper Proterozoic sequence in the southern part of the East Anabar Basin, as throughout the entire framing of the Anabar uplift, has a two-unit terrigenous-carbonate structure. The results of the U-Pb dating of detrital zircons show that there is a difference in stratigraphy of Riphean strata in the north and south of the Anabar Uplift. In the north, deposits of the entire sequence are regarded as Early Riphean; in the south, the thickness of these deposits is reduced to 70 m. The overlying stratum is regarded as Upper Riphean-Vendian. As the strata in the southern part of the East Anabar Basin strata are of younger (Late Riphean-Vendian) age, they cannot be assigned to the Mukun and Billyakh groups. The Riphean-Vendian deposits accumulated mainly through erosion of crystalline rocks of the Anabar Uplift. In the upper part of the sequence, the Vendian magmatic complexes located probably within the Taimyr Orogen played a significant role as provenance areas.

The data on the age of sediments and their sources were first obtained by isotopic methods and lithological-petrographic observations for the Priozersk and Salmi formations in the northeastern Pasha-Ladoga basin. Wide development of coarse-grained terrigenous rocks and peculiar structures point to the proximity of provenances and dominant sedimentation in terrestrial settings. U-Pb dating of 168 detrital zircons revealed that approximately 87% of all grains are Early Riphean in age, while other grains are dated back to the Early Proterozoic. Archean age is documented for only two zircon grains. It is established that detrital material of sandstones from the Priozersk and Salmi formations largely originate from the Salmi Massif (1.55–1.53 Ga) and secondarily from the Svecofennian intrusions of the northern Ladoga region aged approximately 1.88 Ga, which is confirmed also by Sm-Nd data. The occurrence of detrital zircons dated at approximately 1480–1490 Ma indicates development of coeval magmatic bodies in the immediate proximity to the sedimentation basin, which remain undiscovered. The concordant age obtained for the youngest detrital zircon grain points to the onset of sedimentation in the basin after 1477 ± 8 Ma ago. Thus, Riphean sedimentation on the eastern slope of the trough commenced only 20 Ma prior to the emplacement of the Valaam Sill.

This work is devoted to a study of the processes of an increase in the phosphorescence intensity upon photoirradiation of pyrene bromide in aqueous-micellar solutions of surface-active substances. The method of mathematical modeling of the pyrene bromide triplet state deactivation processes is used to determine the rate constant of phosphorescence quenching of pyrene bromide solubilized in sodium dodecyl sulfate micelles by oxygen.

Results of computer simulations of the spectra of magneto-optical rotation (MOR) of the polarization plane for both components of intense bichromatic laser radiation are presented. Dependences of MOR on light intensity and the external magnetic field strength have been investigated. The simulations are based on the theory and method published earlier. Our results coincide with experimental results known from literature. This suggests that new peculiarities of MOR in alkaline vapors obtained by computer simulations can be observed in the natural experiments. (C) 2004 Wiley Periodicals, Inc.

In the paper there are presented the last results of computer simulations on the spectra of magnetooptical rotation (MOR) of plane of polarization for the both components of intense bichromatic laser radiation. Also the dependences of MOR on light intensity and magnetic field strength are investigated. The calculations are based on the theory and method, published earlier. The agreement of calculations for the cases investigated in the known experiments with experimental results permits to hope that new peculiarities of the MOR in alkaline vapours considered in our paper can be observed in the natural experiments.

Results of a numerical study of the Faraday effect arising upon propagation of the light beams with the frequencies ω L1 (resonant to the nS 1/2-nP 1/2, 3/2 transitions) and ω L2 (resonant to the nP 1/2, 3/2-(n+2)S 1/2 transitions) through alkali-metal vapors are presented. Characteristics of the magneto-optical rotation spectra at each of the frequencies are strongly affected by the second intense radiation field resonant to the adjacent transition. When the atoms interact with two strong light waves, resonant to adjacent transitions, and with a magnetic field, the shape of the Faraday rotation spectra depends on the energy shifts of the atomic states that arise due to the dynamic Stark effect and the Zeeman effect (the Paschen-Back or an intermediate-type effect), as well as due to the difference of populations of these states caused by the interaction of the atoms with the fields. The results obtained show that in the frequency selection method, based on the resonance Faraday effect, the frequency of the generated narrow-band beam can be tuned by the intensity of the strong wave, resonant to the transition between the excited states.

The numerical analyses of polarization phenomena is developed for the radiation fields resonant with the transitions nS(1/2)-nP(1/2,3/2) and nP(1/2,3/2) - (n+2)S-1/2 of alkaline atoms. The method of computer simulation of nonlinear resonant polarization phenomena is used, which is based on the solution of the problem of interaction of the real multilevel atom with two laser fields of arbitrary intensity and polarization and with a constant magnetic field. This method is known to be successful applied for the investigation of the polarization phenomena in the atomic gases of the alkaline atoms Na and K. In present paper the whole alkaline group is considered. The represented spectra of rotation of plane of polarization are appear to be qualitatively different for different atoms since atom fine-structure intervals differ very much from each other. The obtained spectra for Rb are in good agreement with the experimental spectra.

Coherent population trapping effect is widely studied for simple three-level systems of different types (Xi, Lambda, V)(1-3). For real atoms situation is more complicated. Atomic levels are degenerated one and in the presence of external fields coupling of magnetic sublevels appears due to as radiation, so magnetic fields, leading to the systems of levels of the higher order. Our theory and method of calculation for interaction of multilevel atom with intense radiation field at the presence of external magnetic field have been applied for considering coherent population trapping effect for such systems.

The spectra of Faraday rotation of the plane of polarization of laser radiation in strong radiation fields and a magnetic field were investigated for alkali atoms. The spectra were obtained using the known method of computer simulation of polarization effects in real multilevel atoms. The possibility of using these effects in the phase-polarization method of selection of laser frequencies was considered.

For alkaline Li, Na, K, Rb , and Cs atoms, the Faraday rotation spectra and other effects of the polarization-plane rotation in strong radiation and magnetic fields are investigated. The spectra are calculated by computer simulation of nonlinear resonance magnetooptical polarization effects for real multilevel atoms. The properties of the spectra of different atoms depend on the relationships between the field and spin-orbital interaction energies.

The method of computer simulations on nonlinear resonant magneto-optical effects developed for real multi-level atoms in the two laser fields of arbitrary intensity and external magnetic field is applied for the polarization effects of different types calculations and investigations of the dependence of the characteristics of these effects on magnetic field strength, intensities, polarizations and detunings of laser fields for alkaline atoms. The essence of the method consists in simulations and analysis of the plots of dependence of quasienergies on parameters (detunings and intensities of radiation fields, magnetic field strength), which are obtained with the help of sorting subprogram, and selection of suitable algorithms for calculations of characteristics of nonlinear resonant magneto-optical effects. One-photon and two photon resonant effects are investigated for wide range of magnetic field strength from Zeeman to Paschen Back effects. Some new features in the spectra of rotation of plane of polarization and circular dicohroizm of different types are predicted. The results show the agreement with known experiments. Such calculations of nonlinear resonant magneto-optical effects in the intense laser fields resonant to adjacent transitions and magnetic field show the opportunity of investigation the modifications of electronic structure due to intense radiation fields and strong external magnetic field in atomic gases and also may be used for the treatment of new methods of phase-polarization selection of modes of tunable lasers.

The interaction of high power laser radiation with the atoms in the external magnetic field leads to the new nonlinear effects due to modifications of populations of the states of the system 'atom plus field.' From one side it can be followed by new peculiarities in the effect of the coherent population trapping and from other -- the effects of the population modifications are important for explanation of regularities of nonlinear magneto-optical effects. The modification of population dynamics due to the parameters of the system -- radiation field intensities, detunings, polarizations, magnetic field strength and orientation, relaxation constants leads to the new features in polarization effects, resonant fluorescence and resonant Raman effects. The new features of the considered theory are that it is built for multilevel atoms and has not restrictions on the probe intensity compared to the pump intensity. The theory and method permit to investigate the populations modifications depending on modifications of the parameters of the system and to find the relation between population dynamics and new nonlinear resonant magneto-optical effects. The considered system consists of atomic gas of low concentration in the constant magnetic field and two monochromatic laser fields of different intensities and polarizations. Analytically the influence of magnetic field on population dynamics of three-level systems have been considered. For real multilevel atom the computer simulations show the dependence of population dynamics on relaxation constants and the differences of this dynamics for different magnetic sublevels of the excited states of the atom. The results agree with known theoretical and experimental works.