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Figure 2.1. Structural
and tectonic lineaments of the "M" quarry area»
Fault tectonics
Ancient (Caledonian) faults laid along major watercourses: a) first order;
b) second order
Intermediate interblock and intrablock discontinuous violations: a) of the
first; b) of the second; c) of the third order;
Young intrablock and feathering discontinuous disorders: a) of the second
and b) of the third order;
Estimated orientation of tectonic stress
Geodynamically
active
seismic dislocations
Outer North block;
Northern Block;
Central block
Tectonic blocks
Southern block with two sub-blocks (U-1) and (U-2);
Outer South block
Western Block;
Eastern Block;
Name of faults of the I and II
orders.
Production facilities
Quarry outline;
External border of dumps
The current geodynamic situation of the area is reflected on the geodynamic map of the
Muruntau mountains and adjacent territories.
The Southern fault is located in the Southern part of the area and is traced far beyond the ore
field. By the nature of the movement, the fault is a left-sided upswing with a vertical amplitude of
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about 500 m and a horizontal amplitude of more than 1000 m. The western part of the fault has an
almost vertical drop. To the east, the fault becomes a steady drop to the south at angles of 70°-80°.
Its power increases to 100-150 m. In the recumbent side, separation cracks are developed, grouped
into linear rocker zones and having sustained elements of occurrence - the azimuth of the fall of
160°, the angles of incidence of 70°-80°. The thickness of the separation cracks is 1-15 m, the
length along the strike is 25-350 m. The eastern link of the fault curves smoothly to the southeast,
and in the sublatitudinal and northeasterly directions, several independent faults branch off from the
main seam, which form a not fully formed structure of the "horse tail" type, complicated by two
narrow conjugated folds. According to aerial photography, it was found that the Southern Fault has
modern geodynamic activity, as indicated by the ravine network formed as a result of quarry
development.
The north-Eastern fault passes through the central part of the Muruntau field. In the north, it
joins the Besapantau fault, in the South – crosses the Southern Fault and goes under the sediments.
According to A. T. Bendik and S. D. Sher, the fault consists of a series of close-in, wing-shaped
faults extending 800-1000 m, along which left-sided movements with an amplitude of up to 40-50
m occurred. The total amplitude of the movements reaches 400 m. The Northeast fault differs from
other faults of this strike by the presence of a phyllonite zone, with a thickness of 5-20 m, which
increases with the approach to the Southern fault. The Muruntau field is divided into two parts by
the North-Eastern fault.
In the quarry, the Structural and Southern faults are recorded, passing, respectively, along
the northern and southern sides. In addition to the North-Eastern fault itself (with index "I"), the
North – Eastern fault (with index "II") is distinguished by a reset-shift with an amplitude of
horizontal displacements of the order of 250-300 m. The power of the zone is 5-15 m.
Thus, as a result of the research, it was found that the area of the deposit's dislocation is
experiencing the next stage of tectonic activity, as evidenced by the facts of differentiated
displacements of rock masses in the horizontal and vertical directions, as well as seismic activity.
The Southern and Northeastern faults have modern geodynamic activity, which is indicated by the
formation of a gully network as a result of quarry development [9-11].
It is established that the existing faults create additional stresses that lead to a change in the
overall stress field in the quarry area, therefore, the determination of the stability of the quarry sides
should be carried out taking into account the stresses created by existing faults of a regional scale.
The analysis of the causes of deformations showed the following:
- almost all types of deformations-collapses, landslides, flaws, subsidence and scree are
recorded at the Muruntau. Landslides and collapses are most developed;
- the areas of the sides that are confined to fault zones, tectonic disturbances, composed of
layered carbonaceous and micaceous shales, and weathered siltstones are most susceptible to
deformation;
- conditions for the formation of separation and slip cracks, structural and tectonic blocks
occur at the junctions and intersections of violations of different orientations, for example: north-
eastern with southern, sublatitudinal or submeridional.
It should be noted that an additional reason for the development of deformation phenomena
on the north side was the large-scale experiment conducted jointly with the institutes of VNIMI and
VNIPIPT in 1976-77, during which a section of a 30-meter pit edge with a length of about 1000 m
was cut at angles of 50-65° with a design angle of 45°. The resulting deformations showed that on
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the upper horizons of the Muruntau quarry, it is impossible to allow an increase in the angles of the
slopes of the pit edges in comparison with the project [12, 13].
At the same time, the analysis of the engineering and geological information accumulated to
date on the deep horizons of the deposit (up to -15
-395 m) indicates an increase in the solidity
and strength of the rock mass at depth.
Information about the deformation of the "Muruntau" quarry to the present time is shown in
Table №.2
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