search for placer deposits

The main geological task:

- define the geophysical characteristics of the alleged pleodorina thalwegs of the river Matysken;
- building a model of paleolake river Matysken with the allocation of plots, looking at the presence of alluvial platinum.

Main types of work:

To solve the tasks set, 11 profiles were laid across the Matysken river valley. The distance between profiles is 1 km. The following works were performed on the profiles: magnetic exploration (step 5 m), electrotomography (step of the feeding electrode 50 m).

Based on the data obtained, geoelectric sections were constructed for each profile. These sections formed the basis of the interpretation scheme, supplemented by the results of magnetic exploration. Examples of constructions are shown below.

The results of operations were consolidated on the General map for each profile was constructed setting the depth of the raft, on the basis of which highlighted the contours of paleochannel river Matysken.

The main tasks of geophysical work in the search for alluvial diamonds:
- determination of the structure of river valleys;
- separation of the section of loose deposits;
- selection of the productive gravel layer

The work was carried out according to the methodology developed by specialists of NWGGK Geocomplex LLC, taking into account the geological features of the area of work. The geological structure of the license area is represented by unique Carnot sandstones intersected by four major watercourses.

At the first (cameral) stage, based on the results of decoding aerial and space images, sections of river valleys that are promising for the formation of placers were identified.

The second (field) stage included two stages of work. At the first stage, the General structure of river valleys within the perspective areas was studied by the EAP method in the electrotomography variant, and the areas of maximum thickness of loose deposits and maximum depth of the paleochannel were identified. At the second stage, the selected areas were studied in detail using shallow seismic survey and electrotomography methods to separate the section of loose deposits and isolate the productive gravel layer.

Based on the results of geophysical work, a series of pits were laid that opened the productive layer at the calculated depth.

The purpose of the work: to determine the thickness of loose deposits and the depth of bedrock occurrence by ground-based electrical exploration using vertical electric sounding, to construct a lithological section with the allocation of loose pebble-sand deposits that are promising for the formation of placers.