Talc Deposits in Afghanistan
The known occurrences of talc are identified in several provinces of Afghanistan i.e. Nangarhar, Kabul, logar, Paktika, Kunar & Maydan Wardak, Parwan province and south east Kandahar province.
The geology of Afghanistan is made by the amalgamation of many small narrow terranes, which broke away from the main Gondwana land and accreted back onto the southern part of Asian plate (Tajik-Turan block) Figure 1. These accretionary events started in the Cretaceous and have continued until recent times. The eastern part of Afghanistan is comprised by Nuristan, Kunar, and Spinghar Blocks (Chapman and Hall, 1997, Wolfart and Moores 1970).
Figure.1 Tectonic sketch of Afghanistan showing the major sutures, locations of ophiolitic rocks, basic intrusions, and talc deposits.
Currently, major production of talc is conducting in Spinghar Block located in eastern part of the country in Nangarhar Province. Technically, the block forms the western margin or end of the lesser Himalayas zones, which is extended from Pakistan. The block lies immediately to the north of the Main Boundary Thrust (MBT) of the Indo-Pakistan Plate and consists dominantly of Proterozoic crust and Lower Paleozoic cover sequences. The block trend nearly east-western and is extended for approximately 125 kilometers, the maximum width is almost 15 Km. The lithology of the block contents erratic gneisses, schist, quartzite, marble and amphibolite metamorphosed to amphibolites facies. Intrusive rocks are derivatives of migmatite-granite and gabbro-monzonite-diorite formations. The former is tentatively dated as Proterozoic and the latter as Early Cretaceous. The origin of talc in this area is controversial either hydrothermal or metamorphic. Generally, talc in this area is formed by the reaction of magnesium rocks with hydrothermal silica as the final phase of regional or contact metamorphism.
Sky Horizon’s Mines
Our mines are located in Kodekhel valley of Sherzad district, Nangarhar province. As per the findings of our chief geologist, the origin of Nangrahar talc deposits is indicated as meta-sedimentary. Talc occurrences in this region are mostly lenticular, vein types, and varying colors i.e., white, grey, greenish and cream white. The geochemical analyses of these deposits indicate variable content of SiO2 and MgO where the silica reaches upto 65% and Mg up to 30% showing world-class high-quality talc. The talc at his area is 99% pure and its whiteness ranges from 91 to 98%.
Our chief geologist has conducted detailed study of these mines and published an article with title “Ore Genesis and Geochemical Characteristics of Carbonate-hosted Talc Deposits in Nangarhar Province, Afghanistan” in Resource Geology The geochemical and mineralogical analysis of various talc samples has been conducted in standard reputed geochemical laboratories of Akita University, Japan, Turkish labs and SGS. The geochemical and mineralogical analysis includes XRF, XRD, EPMA, Optical analysis and physical properties of talc. The detailed petrography and XRD of the talc and different minerals that is conducted by our chief geologist are is given below:
Figure 2: Presence of dickite (clay mineral), lizardite, chlorite, ilmenite and vermiculite in host and talc rocks. (give a talc rock photograph also)
Figure 3: Coexistance of altered rocks with talc rocks
