[en] The description of gamma-spectrometric studies of the Venus surface rocks, performed using the ''Vega-1'' and ''Vega-2'' landing spacecrafts, is given. Data on the content of uranium, thorium and potassium in the Venus surface rocks in points of the spacecraft landing are provided. The experiments conducted have shown that the rocks investigated correspond to the Earth gabbroids and tholeiite basalts as regards natural radioactive elements in them

[en] The problem of the Venus-9 and Venus-10 space probes is to define the character and the rock composition of the Venus. The content of natural radioactive elements of U,Th,K in the ore-rocks of the planet has been determined by gamma-spectrometers. The spectrometers have been calibrated on natural earth rocks. The measurements have been taken in the atmosphere and on the surface of the Venus in the range of 1.15-1.55 MeV, 1.55-2.3 MeV and above 2.3 MeV. The preliminary analysis has shown that in both points of the planet there are rocks similar to the basalt type earth rocks. The ratio of the K and U content accounts for (1-2)x10⁴. The data obtained for the Venus have been studied on the potassium-uranium systematics graph of the Earth magma rocks. The analysis makes it possible to assume that on the Venus, as well as on the Earth, there occurs a process of differentiation of the planet primary matter accompanied with the formation of mantle and crust with considerable content of rocks of fundamental composition in the latter

[en] The operation of the densimeter on the Venera 10 automatic interplanetary station is described. The densimeter provides rapid and precise determination of rock density by the radiation method. The main components of the instrument are sensors and an electronic unit. The high temperature Geiger counter with neon-xenon-oxygen filling is used as γ-radiation detector. As the sensor operates at 500 deg C, measures have been taken to reduce the influence of insulation leakage on the instrument reading. The insulation of a connecting cable is made of high temperature fibre glass, the resistance in the detector circuit at 500 deg C being not lower than 1x10⁸Ohm. The electronic unit comprises power amplifiers, descriminators, vibrators and counting registers. To increase the unit operation reliability the registering unit of the instrument is based on integral schemes. Using the measurement results the surface rock density of the Venus is evaluated by 2.8 g/cm³ with mean square error of +-0.1 g/cm³

No abstract available

[en] A radiation densitometer for the first measurement of the Venusian rock density was installed on the automatic station 'Venera-10' which landed on the planet in 1975. As a result of the experiment it was established that the rock density is 2.8+-0.1 g cm^-3. The construction of the densitometer and its operation on the surface of the planet as well as the results of the experiment are given in this article. (Auth.)

[en] The inverse problem of determination of the petrochemical composition and geologo-petrographical characteristic of the Venus rocks by content in the natural radioactive elements is stated. Data bank including U, Th, K contents, silicate analysis, the name, geotectonic position, bedding conditions, age has been collected. U, Th, K contents found experimentally in the Venus rocks in places of the ''Venera-8, 9, 10'' and ''Vega-1, 2'' interplanetary station landing are known. Probabilities of the Venus rock correspondence to the families of the Earth magmatic rocks are calculated. It is established that the rocks, investigated by the ''Venera'' and, ''Vega'' stations, are similar betwee each the coutent of natural radioactive elements and correspond most of all to sienites and trahydacites