Integrated geological and geophysical study of the Tagil river valley morphology in its middle course

Relevance. Integrated geological and geophysical studies of a bridge in the Makhnevo village area are considered in the frame of the Urals eastern slope geology. Research objective is to study the lithology of the underlying part of the valley floor, determine soil physical and mechanical characteristics, and study a complex of fluvial terraces. Results. Relief elevations across the river valley have been studied, and four main fluvial terrace levels typical of the Urals eastern slope have been identified. An unstable section of the streambed with a canyonshaped valley above the neotectonic unwarping zone has been identified. The geological section of the river’s floodplain and streambed were studied based on geological and geophysical data. A change in the physical properties of glauconite sandstones and clays of Paleogene age in the recent underlying part of the river valley has been established. Layers of sand and glauconite sandstone that can be developed have been found at the new bridge site near the existing sand and gravel deposit. Conclusions. A complex of terraces of the Tagil river valley in its middle course is typical for the Urals eastern slope. The paleovalley is cut into a Paleogene glauconite sandstone layer. In the underlying part of the valley floor, changes in sandstones and clays physical properties have been recorded, and the presence of hypogene minerals was revealed. These are the signs of possible neotectonic processes in the series of the Cenozoic and Quaternary deposits.

Complex geophysical studies of the asar body in the Kaluga region

This paper describes complex geophysical studies conducted on an asar body in the Kaluga region. In particular, the anomaly of the apparent polarizability is studied. Complex interpretation of geophysical data, comparison with drilling results, as well as measurements on drill samples made it possible to define the nature of the anomaly and confirm the presence of areas with a high percentage of magmatic gravel and cobble within the sand-gravel deposit, which are characterized by high values of electrical polarizability.

Characteristics of native gold at Kosumnerskoe placer gold deposit (the Nether-Polar Urals)

The paper presents the results of a study of heavy mineral concentrates of Kosumnerskoe gold deposit as well as the native gold from them. This gold deposit includes two gravel deposits. The granulometric composition, morphology, roundness, flatness, presence of intergrowths of gold with other minerals, as well as the character of the surface, the chemical composition and internal structure of gold, have been investigated. Based on these results, the placer gold of rivers Narta-Yu and Nester-Shor has been concluded to be similar in morphology, chemical composition and internal structure so it allows attributing them to a single type of motherload, which could be named as gold-polysulfide-quartz type. On the results of the analysis of two gold deposits of this field, the gravel deposit of the river Nester-Shor has been concluded to be elder than gravel deposit of the river Narta-Yu.

Substantiation of field of application of combined (traditional and physicaland-chemical) geotechnologies for the development of gravel and secondary gold deposits

Problems of accumulation of technogenic tailings dumps and as a result of sluicing of gold sands of gravel deposits are considered in article. Additional recovery of fine and dispersed gold from a mineral mass of such technogenic formations can be carried out with use of physical and chemical geotechnologies. The factors influencing on the choice of a way of development of the gold gravel deposit are listed. The mathematical model of a gravel deposit is developed for the solution of the problem of multifactorial assessment of technological options of processing of gold sands. The scheme of the combined development of the gravel gold deposit is offered. Cuvette gold leaching experiments with the photo-electro activated solutions on various reagent basis were executed for the assessment of a developed scheme. Material for the researches was a gravity concentrate (schlich) fraction obtained by tailings gravity concentration (Kia gravel deposit, Transbaikal Territory). The first stage of gravity concentrate (schlich) processing included contacting with photoelectro activated carbonaceous solution (NaHCO3). The first leaching reagent scheme (cyanide solution concentration of 1.5 g/l prepared on the basis of photo-electro activated the peroxide - carbonaceous solution provided 66.8 % gold extraction. The second reagent scheme (active chloride-carbonaceous solution) provided 88.9 % gold extraction.