Semi-detailed exploration of mercury and associated elements in the Khangoli area of Maku
Kawoshgaran Consulting Engineers
Based on a contract between the Industries and Mines Organization of Azerbaijan-e Gharbi and Kawoshgaran Consulting Engineers, a semi-detailed exploration project started in the Khangoli district, in the Siyah-Cheshmeh of Maku. The areal extent of the studied zone is 30 hectares that explored for Hg, Au and Sb. It should be noted that the prospection and preliminary exploration in the area were done by this company at 1989 and 1993 respectively. During those studies the current zone was introduced as the first priority of further exploration.
The study area is located in the Azarbaijan-e Gharbi province is accessible through the Siyah-Cheshmeh to Maku road. The distance between the Siyah-Cheshmeh to the study area is 49 Km that includes 29 Km asphalt and 20 Km earth road.
1:1000 topography and geology maps of the area were prepared. Trenching (1884 m) and excavation of 4277 cubic meter soil materials, geochemical survey, geoelectrical survey (IP, RS) and electromagnetic survey (V.L.F.) are the other carried out activities in the project. After these steps, the obtained data were analyzed.
Geologically, this district belongs to the Khoy-Maku ophiolitic zone. Ultrabasic brecciaed serpentinite, andesitic rocks, radiolarite shales, conglomerate, shale, marl and sandstone are the existing rock units in the region. These rocks have suffered hydrothermal alteration and contain silicic veins with iron oxides. There are small sub-volcanic micro quartz diorite bodies in the area. Generally, the lithologic units have tectonic contacts with rare normal boundary. There a major and two minor fault systems in the region. The main system is trending NW and minor systems trending N and E. alteration and ore mineralization in under influence of major fault system.
To unravel the mineral deposit, determine the mineralized zones, host rock, and lithogeochemical sampling, 8 trenches were drilled along N50E, and six trenches drilled along mineralized zones. These trenches were used as litho-geochemical profiles. Sampling was done by channel-chip method. Although the precision of analyses for Hg and Au is low, but statistical assessments cited that the geochemical anomalies are accordable with field evidence. Determination of erosion level of geochemical anomalies (Hg) based on the coefficients of indicator elements showed that the anomalies are correlating with mineralization of supraore elements. Generally the attained coefficients of trenches T5-T6-T7 and T8 (southeastern portion) are lower than T1, T2, T3 and T4. in other words, the quantity of supraore elements such as Hg decreased and inversely the quantity of subore elements such as Zn and Cu increased. The low topography relief of the southeastern section and therefore the deeper erosion than northwest, can justify this observation. The main problem of geochemical analyses is their precision; so ore grade can not be the suitable measure for determination of average Hg grade and estimation of ore reserve in the mineralized zones. In addition, there is large difference among the analyses results of preliminary exploration and the current step.