Excavation of Trenches and Bulldozer Cuts

Following the completion of prospecting works, trenches and bulldozer cuts are excavated along zones of ore mineralization. The main volume of trenching and cut excavation is carried out in detailed areas, in fields and zones of development of small bodies identified based on geophysical data, as well as in areas where mineralized zones are concealed beneath Quaternary deposits.

Surface mine workings (trenches and cuts), as one of the principal types of prospecting works, are carried out to expose bedrock containing mineralized zones and ore bodies (stockwork zones, quartz veins, metasomatites) along exploration profiles and between them. The average spacing between surface mine workings is approximately 30 m.

Bulldozer cuts are planned in areas where the thickness of overburden is accessible for excavation (up to 5–7 m), provided that the cut is initially excavated by a bulldozer, followed by further excavation of a trench along the cut floor. The average depth of excavation along the cuts is 1.0 m, including 0.3–0.5 m into bedrock.

Trenches are planned in areas with limited development of Quaternary deposits, not exceeding 2–3 m in thickness, in order to expose and sample mineralized zones and potential ore bodies. Cuts and trenches are oriented perpendicular to the strike of the mineralized zones and their host rocks. The length of the workings is determined by the need to expose the ore-bearing zones across their full thickness, to the extent that bedrock can be exposed beneath the Quaternary deposits.

In areas identified based on the results of prospecting and evaluation works, trenches and cuts are planned to expose and sample primary and unconsolidated (alluvial and proluvial) sources of gold and other mineral resources, based on previously identified lithogeochemical and heavy-mineral sampling anomalies. Given the absence, in most cases, of clearly defined boundaries of mineralization and its irregular continuity, the previous operators initially excavated main trenches across the full thickness of the mineralized zones and across the full width of the epicenters of contrasting lithogeochemical anomalies.

After removal of the loose overburden, the rock along both walls of the trench is scaled and cleaned, followed by manual excavation to a width of 0.8–1.0 m along the trench floor. The trench is excavated to expose massive and less erosion-degraded bedrock; the excavation depth depends on the degree of rock weathering and disintegration. The walls and floor of the trenches are cleaned with metal brushes as directed by the geologist and, where necessary, washed with water. The geological team marks sampling intervals with paint along the trench walls and with numbered sample stakes along the trench floor.

Following geological documentation of the trenches and cuts and continuous channel sampling, the final survey control of the sampling intervals (and individual samples, where necessary) is carried out, together with a mine-surveyor survey of the workings. An acceptance certificate is prepared for each trench, specifying the quantities and types of work performed.

The excavation of trenches and cuts is carried out in accordance with the Work Plan, the excavation passport, the fieldwork program, occupational health and safety requirements, and environmental protection regulations.