Location: Saikhandulaan, Dornogovi
12720X Zalaa is located in Saikhandulaan soum of Dornogovi aimag and the license was granted to Quartz Crystal Trade LLC on 11th October, 2006 in order to conduct geological study and exploration on the Khadan Tsagaan quartz primary deposit. On 18th January, 2008 the exploration license was transferred to Topazstone Mining LLC based on order 55 of the Geology and Mining Cadastre Division. The license was subsequently transferred to Belgravia Mining LLC on 19th September, 2008. The Zalaa licensed area is located 48 km to the southeast of Ulaanbaatar, 120 km to the west of Sainshand and 20 km to west of Saikhandulaan soum. The area has shallow hills but no rivers or springs. Although dry channels and dry lakes are common in the Gobi region, these areas are only occasionally restored storm waters. With extreme climate conditions, the temperature ranges from -15oC to +39oC. The wind predominantly blows from the northwest with speed reaching 25 m/sec. The region contains most types of flora and fauna native to the Gobi.
1935-1936, In the western part of Saikhandulaan province 1:200,000 scale geological mapping were completed by geologists Chaikovski.V.K and others and identified regional geological formation of this region for the first time.
1935 , 1:50,000 scale geology-hydrogeological mapping were completed by geologists Borodkov.V.N and others. They identified water wells and determined water composition and quality.
1940-1942, 1:50,000 scale geological mapping were completed by geologists Jelubovskii.V.S and others in the western part of Saikhandulaan province
1963-1965, Magnetic surveys were completed on the territory of Saikhandulaan province.
1972-1973 1:200,000 scale geological mapping were carried out by Mongolian geologists Sanjaadorj.D and others. Bayan Uul and Zalaa Tsagaan quartz occurrences were discovered from this study.
1991-1994 Geologist Bold.N and others conducted reconnaissance and prospecting work on the Bayan-Uul and Zalaa Tsagaan quarts occurrences. Resource was approved as a result of this work in the C1 category 878, 0 thousand tons of quartz.
Abundant occurrence of Middle-Upper Devonian sediments, south east and south west of the licensed area were developed volcanogenic-sedimentary rock of Tsagaan Tsav Formation of the Upper Jurassic-Lower Cretaceous age. Mineralization of this sediment is coarse to fine grained sandstone, clay schist, siltstone and main strike is to the north east direction. Also Upper Quaternary and Quaternary sediments were developed in the lakes and marshy area and they are represented by alluvial loose sediments. As a result of geological mapping in 2008 the geology formation of this area was defined. In the central and south east area were occurred strongly silicified goethite, hematite, limonite altered basalt, quartz veins and veinlets. In the west, north, south and east area were occurred brown-green, dark colored andesite-tuff, andesite, sandstone-tuff, siltstone and the main structure is 60-70° to the northwest side striked Middle-Upper Devonian volcanogenic-sedimentary rocks covered by Upper Jurassic-Lower Cretaceous basalt and tuff.
In the North West side of the area 2-3 meter of width, 25-30 meter of length strongly silicified alteration zones cut by quartz veins and veinlets of Middle-Upper Devonian volcanogenic-sedimentary rocks were identified. These alteration zones are weak goethite altered and mineralization is not clear in the surface. But many fractures that originated from tectonic fault are visible.
Zalaa Tsagaan quartz occurrence observed in the licensed area and Bayan Uul quartz vein occurrence is located 5.0 km to the south east of it. Quartz in this vein is white, medium to fine grained, and vein size is 20-50m of average width and 280 m of length. Sixteen samples were taken from four trenches on this quartz occurrence and from the results of geochemical analyses a grade of SiO2 from 99,85%-99,99% was revealed. On average a 99,97% grade and other mixture of oxides are very rare. The resource of Zalaa Tsagaan vein type quartz occurrence were estimated at 1082.9 thousand tones by Р1 category over the area of 83 m length 1/3 of distance to the depth of the studied part of occurrence. Also in the central and south east area strongly silicified goethite, hematite, limonite altered basalt, quartz veins and veinlets were found. Preliminary it was concluded that the vein type of quarts can be used to produce household items, such as glass for windows etc. As stated above, this area is very interesting for geological structure formation and also several vein types of quartz were identified. Furthermore two mining companies for vein type of quartz are located near the licensed area and therefore this area is commercially significant and needs to do more exploration (geochemical and geophysical survey) and excavation work (trenching and sampling) to verify dispersion distance and size of vein type quartz.