Writers : Vahdatparast, Maryam; supervisor: M. Razmara; advisor: M. H. Karimpour
Refference : M.Sc.Thesis _ Ferdowsi University, Mashhad
Publishing Year : 1382

Abstract :

The Goushekarnar a nd Sibzar rn ines are situated in the central Lut block about 45km Northeast of Eshgh Abad in the Ozbak Kuh mountain range. The host rock of the ore bodies is thick layer to massivc dolomite of Sibzar formation. The lithology of the Formation consists of limy dolomite tc dolomitic limcslone and sometimes limestone. The limited volcanic rocks are obscrved in the area. They consist of andesite to latite and basal tic ،andesitc to basalt in the Goushckamar and Sibzar area respectively
.The miineralization in the area was control Ied by a system of faults and
joints. The Sibzar dolomite shows hydrothermal aIterations in some areas as well. This alteration appears as colour changes, recrystalisation and Iron exchange i n t he crystal s tructure of dolomite. The dominant alterations in the volcanic rocks are saussuritization, kaolinitization, chioritization and .opacitiz ation
Based on the paragenesis and geochemistry studies, two stages of mincralizations are identified in the area. In the first stage (non sulfide .mineralizati on), magnctitc and specularite associated with barite, gypsum an . quartz were formed. But in the second stage (sulfide mineralizatiot 1) galcna sphalcritc and pyritc were formed. The primary oxides and sulphides wcrc? replaced by a series of secondary minerals such as iron oxsides (e.g. hematite limonitc) , manganese oxide ) pyrolucite ) , smithsonitc, hemimorphite and cerusite. The main economic ore minerals are galena and sphalerite in the . Goushekamar and Sibzar areas respectively Based on remote sensing studies two main trends of faults and joints ) E-W
and NE - SW) were identified in the area. The mineralization in the Ozbak Kuh . area is associatcd with N37E set of fault
The geochemical studies s howed positive relationships between important elements such as ) Zn- Fe) , (Pb -Zn), ( Pb-Fe )and ( Pb - Ag )in the Sibzar area. On the other hand, such relationships were not observed in the Goushekaniar area

Sphalrite from Sibzar arca displays colour banding ranging from light (darc )
1>1 ,and Cu. The colour banding in sphaleritc is controlled by local conditions
. hangcs and rapidly prccipatcd crystals from solution enriched in Fe and Cu Based on SEM and X RM studies, two sphaleritc subgroups were identi fi ed in )%12.2<%5>the area: low Fe-sphal crit c (Fe<1% ) and high Fe-sphalcrite (Fe The presence of two distinct sphaleritc chemistries indicates that Zn and Pb
sulphide mincrali zation was a two stage proccsscs.

Subject List : Zinc and Lead