Possibility of application of the method of observing the natural impulse electromagnetic field of the earth for allocation of watered faults on the example of Yeristovo quarry
One of the important tasks of operating the Yeristovo iron ore deposit is to reduce the level of water inflows, which complicate its development. The article presents the results of applying the express method of observing the natural impulse electromagnetic field of the Earth to isolate flooded faults in areas adjacent to the Yeristovo quarry. The features of the geological and tectonic structure of the territory of the Yeristovo field are considered. According to the tectonic map of Ukraine, the main deep faults characteristic of Srednepridneprovsky and Ingulsky megablocks of the Ukrainian shield in the area of study sites are highlighted. A method for conducting field studies by observing the natural impulse electromagnetic field of the Earth is presented. The studies were performed using equipment such as a radio wave indicator of the stress-strain state of rocks according to a previously developed technique. According to the results of the field studies, for the first time, maps of the density of the natural impulse electromagnetic field of the Earth flux were constructed for this area, which made it possible to isolate and trace the positions of watering faults. In addition, to visualize the most difficult fragments of the structure of the plots, three-dimensional models were built. Four zones of reduced values of the natural impulse electromagnetic field of the Earth (less than 3 conventional units) were identified on the studied areas. They are characterized by: the western tectonic disturbance - has a width of about 60 m and a strike azimuth of 3-5˚. The tectonic disturbance following it to the east is about 50 m wide and the strike azimuth is also 3-5˚. It is followed by an insignificant tectonic disturbance, which inherits the direction of the Krivyi Rih-Kremenchug break and has a width of about 20 m. In the east of the studied sites, there is a tectonic disturbance with a strike azimuth of 3-5˚, about 20 m wide. Since the azimuths of the strike of the identified tectonic disturbances coincide with the Main and Yeristovo faults characteristic of this territory, the identified faults are their feathering. On the basis of the conducted research, it is possible to recommend the use of water catching wells using a reasonably economical and reliable method of observing the natural impulse electromagnetic field of the Earth. It is advisable to lay them in the zones of minimum values of the natural impulse electromagnetic field of the Earth, within the southern parts of the research sites. The use of advanced observations will avoid unproductive costs when drilling water-reducing wells.