Estimation of consequences of the petroleum flood from pipeline in Usinsk has shown that in samples of the bottom sediments taken up after the leakage the concentrations of PAH of the anthropogenic origin are somehow increased, however there are not anomaly high ones. In general, anthropogenic influence is detected at the molecular markers level and it is far from being catastrophic.
The study of the geological structure of carbonatite massifs is a rather difficult task due to their very complex structure.
As is known, the main information on the structure of the consolidated continental crust is currently obtained by means of depth seismic soundings (DSS). According to DSS data, everywhere in the Earth's crust, gentle seismic boundaries are traced.
In 1980 in the northwestern part of Ladoga and southwestern Karelia the production and geological association Sevzapgeologia and the Problem Research Laboratory of geological and geophysical studies of the Baltic Shield of the G.V.Plekhanov Leningrad Mining Institute conducted deep seismic studies by methods of deep seismic sounding and exchange waves from distant earthquakes (MOB3) along the profile and the Problem Research Laboratory of Geological and Geophysical Research of the Baltic Shield of the Leningrad Year Institute named after G.V. Plekhanov conducted depth seismic studies by methods of depth seismic sounding (DSS) and exchange waves from distant earthquakes (MOVZ) along the profile of Lahdenpokhya - Lake Segozero, which is hereinafter referred to as the Priladozhsky ...
Iceland and the Baltic Shield have significantly different geologic structures, although in both regions high-velocity rocks of consolidated crust come to the surface ...
In 1976-1979, the production and geological association Sevzapgeologia and the Problem Research Laboratory of Geological and Geophysical Research of the Baltic Shield of the Leningrad Mining Institute performed depth seismic surveys (DSR) in Central Karelia along the profile of the city of Kem - Lake Tulos, which is a continuation of the international geotraverse I, passing from the Alps to the Baltic Shield through the territories of the FRG, Czechoslovakia, Poland and the USSR ...
The year 1927 was coming to an end. The country of the Soviets was overcoming the devastation of the world and civil wars. On the agenda was set the issue of development of the national economy, primarily heavy industry. For this purpose new fields were needed, they had to be found quickly and economically ...
The Pechenga-Allarechensk nickel structural zone of the Kola Peninsula is one of the few ore districts of the USSR, where ore seismic survey by the reflected wave method (RWM) for solving structural problems began to be applied for the first time and has been systematically carried out for a long time.....
In the study of seismic exploration of complex geological areas successfully used developed in the USSR under the leadership of L.A. Ryabinkin method of adjustable directional reception (RNR), using one of the most common interference systems of wave separation. ...
On the Baltic Shield, in foreign and Soviet parts of it, to date, a large amount of work has been carried out by methods of explosive and conventional seismology, allowing to determine the sole of the consolidated crust - the Mohorovičić discontinuity (M) - in its various areas.
To study the deep structure of the Pechenga ore district, the reflected wave seismic (RWS) method has been successfully applied in recent years. Consistent complication of the tasks solved in this case, causes the need to detail the ideas about the velocity section of the studied area, for which data from both borehole and ground seismic observations are used.
The solution of the important question about the accuracy of seismic boundaries construction not only in the Pechenga, but also in other ore areas is complicated by the complex character of the registered wave fields and the change of velocity sections over the area, which is explained by the strong dislocation of folded structures composed of different complexes of high-velocity crystalline and metamorphosed rocks.
Seismic studies within the Pechenga structure are carried out by the reflected wave method along systems of longitudinal profiles combined with spatial observations. The seismic profiles are oriented, as a rule, crosswise to the prevailing strike of the rocks.
Based on the vast experience of seismic exploration in oil and gas bearing areas, the methodology and systems of observations by reflected and refracted waves in relation to the study of hollow structures of sedimentary rocks have been well developed and are still being improved. At the same time, in recent years, seismic exploration method is increasingly used to study the consolidated crust and, in particular, structures composed of highly metamorphosed and crystalline rocks in regions where ore deposits are being searched for. Under these conditions, seismic exploration is tasked with studying very complex folded and highly dislocated structures formed by rocks that are relatively poorly differentiated in terms of elastic wave propagation velocity.
Until recently, seismic exploration has been little used in the study of crystalline structures of ancient shields. In Karelia in 1958-1959, during the International Geophysical Year, the first regional studies of the ancient shield in the USSR were carried out by the method of deep seismic sounding. In 1960-1961 seismic works in combination with other methods were continued in the north-west of the Kola Peninsula in connection with the study of the tan structure of the Pechenga effusive-sedimentary series. On the basis of these works, performed by the Western Geophysical Trust, VSEGEI, Leningrad Mining Institute and office “Spetsgeofizika”, a number of fundamental issues of application of seismic exploration in the complex conditions of the Baltic Shield and obtained interesting homologic results.
Separation of crystalline rocks by elastic properties is crucial in determining the applicability of seismic exploration for solving geologic problems in ancient shields. In Northern Karelia, special parametric seismic soundings were carried out in 1958 by the Spetsgeofizika office and the All-Union Research Geological Institute with the participation of the Leningrad Mining Institute. During these observations, made in conjunction with depth seismic sounding (DSS), the same receiving equipment was used: low-frequency seismic receivers of the SP-15 type and seismic stations SS-26-51D, reconstructed for low-frequency reception. Most of the records of elastic waves from explosions are made at the same bandwidth as the GSZ (5- 15 Hz), a smaller part - at medium-frequency filtering (30-50 Hz).