Complementary geochemical exploration in the Gazik and Khushab sheets
In order to reassess the geochemical data produced during last 25 years, a contract was signed between GSI and Madanafarin Consulting Engineers at 2000. The study area includes Gazik and Khushab sheets at southeast of Birjand. The project involves three steps: 1- analysis of geochemical data and comparison of the results with the work of BRGM geochemical and hammer prospection data (1976); Application of remote sensing and identified mineral zones such as Passhurak and Maldar chromite, for controlling the results and sampling.
2- In the second step, field visit of anomalies were done and sampling network was designed. Required samples were taken for geochemical analysis and heavy mineral, thin section and polished section studies. 1:1000 geology map of Khushab was prepared.
3- Analysis of obtained data from lab analysis of samples, introduction of deposit and genetic-type modeling. Complementary geochemical survey was conducted in two zones, the quartz diorite mass at north of Khushab village that is 2000 * 4000 m; Dastgerd chromite indication, 4 Km away from the southeast of Dastgerd village that is 2.5 * 2 Km. The sampling distance in the Khushab area was 50 m, mainly of rock type, stream sediment and soil. The main factor in alteration of Khushab granite was the geochemical absorption dam that caused a pseudomineralization with no economical value. The Dastgerd chromite indication was studied by 26 heavy mineral samples and stream sediments. It occurred in dunites along with harzburgites. The chromium concentration reaches to 960 ppm in stream sediments. But heavy mineral samples had up to 7270 ppm chromium. Of 24 stream sediment samples, 15 ones had anomalous content of Cr. This zone was recommended for more detailed studies.