Vol 76

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 theoretical field of irregularly shaped objects have to be constantly calculated in the process of interpreting gravity anomalies by the method of selection. There are enough reasons to use a body bounded by first-order surfaces as a universal element of the density model of the geologic medium during the fitting ...

The introduction of high-precision quantum magnetometers into practice has significantly expanded the range of tasks for which magnetic reconnaissance is used. Large volumes of aeromagnetic surveys are performed, in particular, to identify fold structures in sedimentary strata of platforms and geosynclinal areas in connection with the search for oil and gas ...

One of the factors controlling the location of bauxite deposits in the Wind Belt (eastern slope of the Baltic Crystalline Shield) is the presence of depressions in the relief of the crystalline basement rocks. The study of the relief of the crystalline basement in some cases can be carried out successfully by the VES method ...

High weight of charges, release from cumbersome drilling and blasting operations, and the resulting savings and protection of the ecological environment are obvious advantages that determined the problem laboratory of the LGI to set up work on the registration of seismic waves arising from industrial explosions and their use to study the structure of the Earth's crust in the eastern part of the Baltic Shield ....

Despite the large volume of seismic exploration in ore areas is still poorly covered the question of the properties of seismic boundaries in igneous rocks. The information about them is based mainly on the results of interpretation of kinematic characteristics of wave fields, which give an opportunity to get a fairly complete idea about the morphology of boundaries, but very little - about their detailed velocity structure ...

Specificity of seismogeological conditions of ore areas composed of crystalline rocks, complicates the use of traditional seismic exploration methods of building velocity models based on generalization of data on the determination of the effective velocity ...

For a number of years during seismic exploration by the reflected wave method (RWM) in the Pechenga region ground azimuthal units are used, and since 1976 - and borehole - during works by the method of vertical seismic profiling (VSP) ...

Interpretation of materials obtained by mapping of bottom sediments, tracing of acoustic boundaries by means of sounding methods at water depths exceeding the depth of section illumination and by an order of magnitude exceeding the width of the sounding wave packet, does not cause special difficulties ...

The careful attitude in our country to historical monuments, enshrined by the law “On Protection and Use of Historical and Cultural Monuments” adopted in 1976 by the Presidium of the Supreme Soviet of the USSR, urgently requires the introduction of new methods in the field archaeological practice, which without prejudice to the study of monuments would allow to reduce the cost and speed up the acquisition of information required by the archaeologist ...

When measuring the thermophysical properties of rocks by the heat wave method, two probes are introduced into the material under study: a heat pulse source and a thermosensitive element; the thermal conductivity and diffusivity of the material are determined by the change in the parameters of the heat wave ...

Gamma-spectral logging to separately determine the concentrations of natural radioactive elements emerged and formed in the USSR as a new radiometric method in the mid-60s. Thanks to the works mainly of the radiometric laboratory of the LGI, this method is widely recognized and successfully applied in prospecting and exploration of radioactive ore deposits. Its main advantages over geologic sampling of well cores are in efficiency, cost-effectiveness and the ability to fully investigate the well regardless of the core yield ...

The most important characteristics of the scattered -radiation field include: the position of the inversion region, the magnitude of the saturated volume, and the depth. There are numerous experimental data and individual calculations on these or other field parameters ...

The effective mass attenuation coefficients of gamma ray attenuation of radioactive ores have close values for the integral spectrum measured by the NaI(Tl) scintillator in a standard screen, and for the energy windows used in gamma-ray spectral logging and ore sampling ...

X-ray spectral determination of light elements is notoriously difficult due to the low fluorescence yield, X-ray absorption on the path from sample to detector, and insufficient resolution of the commonly used proportional counters ...

Interest in the study of the behavior of K in the zone of hypergenesis has become particularly important in connection with the widespread introduction of gamma-spectrometry in the practice of prospecting for ore deposits, which makes it possible to obtain information on the distribution of K in loose sediments over large areas and use these data in various geological and geochemical constructions ...

In geochemical studies, two basic parameters, mean grade and variance, are used to characterize rocks and ores. It is easy to show that regardless of the nature of the spatial distribution of element content in the studied object at a sufficiently dense and uniform sampling network, the average content of the element is equal to the arithmetic mean ...

Anomalous changes in concentrations due to scattering halos are often comparable in their parameters with fluctuations of the geochemical background and with its changes due to the change of rocks. In these cases, it is necessary to use such a method of processing the survey results, in which the geochemical background, carrying information about the geological structure or regional geochemical patterns, is distinguished from the field of measured concentrations, and local anomalies of prospecting interest are identified

Fundamental studies of Y.A.Bilibin, V.N.Zverev, A.I.Kuks, A.I.Kazarinov, N.V.Petrovskaya and other scientists are devoted to the issues of gold mineralization location in Central Aldan. With some disagreements on the conditions of formation, connection with lithology, tectonics, magmatism, most researchers unconditionally recognize the gyzrothermal-metasomatic nature of gold mineralization of the area and the connection of the latter with the Mesozoic activation of the shield ...

In ultrabasic-basic rocks, copper-nickel and pyrrhotite ores, cobalt is a constant companion of nickel. In this regard, the observed geochemical anomalies in moraine sediments above the above objects are characterized not only by elevated nickel and copper, but also by cobalt ...

The geological structure of Afghanistan is still little studied, except for some areas of the northern part of the country, the territory of which since 1958 has been systematically studied in connection with the search for oil and gas. Here, with the technical assistance of the USSR discovered a number of oil and gas fields ...

The logging gamma-spectrometer developed and tested by us contains three counting-resolving channels providing continuous recording of gamma equivalent concentrations of U, Tb and K, and an integral channel. The counting-resolving channels can be used in the mode of continuous or discrete recording of the average pulse frequency in specified energy windows ...