Writers : Malekzadeh Shafaroudi, Azade; supervisor: M. H. Karimpour; advisor: A. Mazaheri
Refference : M.Sc. Thesis, Ferdowsi university, Mashhad
Publishing Year : 1382

Abstract :

Taknar polymetal (Cu-Zn-Au-Ag-Pb) deposit is part of Taknar zone. This zone is an uplift between Great Kavir fault (Daruneh) in south and Taknar fault in north At less three stages of mineralization are identified in Taknar area:I
polymetal Cu-Zn-Au-Ag-Pb mineralization (Ordovician) 2) mineralization associated with mesozoic intrusive rocks, and 3) epigenetic vein type
Taknar deposit has outcrop in four areas (Tak-I to Tak-IV). This study was
concentrated in Tak-I and Tak-II polymetal deposit. Ancient working such as old pits trenches, and slag are present in the areas. Polyrnetal mineralization has formed in ,special horizon within Taknar formation .Taknar formation in Tak-I and II areas was contain quartz- rich pillitic rocks subarkose and subvlocanic intrusive. They were undergone low grade regional metamorphism in green schist facies after mineralization and changed to: sericite schist, chlorite sericite schist, chlorite schist, garnet- bearing sericite schist and ,metagabbro- diorite to metadiabasePolymetal mineralization forms three styles such as: layered, massive and stockwork. Shape, dimension and location of mineralization has changed due to faulting at different time. Stockwork zone in Tak-I consisit of 2 to 10 vienlets in square meter. Host rocks are meta-sediments and meta-subvolcanics. Major minerals are -pyrite + Chalcop +? Magnetite with Chlorite + Quartz + Sericite alteration in meta sediments and Propylitic-silicification alteration in meta-gabbro-dionte to meta diabase. The contact between stockwork zone and layered zone is fault control. The zone is present in layered zone east Layered zone strike is NE-SW/dip is 27° NW. Its dimension has changed and is +9x20 m. layer thickness is 1 mm to 1 .5 Cm Major minerals are: M agnetite + Pyrite + Chalcopyrite + Sphalerite + Galena ) + sulfosalts + Gold) with Chlorite+ Carbonate Sericite alteration.

Due to high magnetite, mineralized zone appear as massive. Visual thickness of massive zone is 1 to 3 m and its length is about 12.5 m. Its contact with the layered + zone is fault control. Massive zone contain: Magnetite pyrite + Chalcopyrite Sphalerite + Galena ( sulfosalts? Gold) with Chlorite? Carbonate? Sericitcalteration .
Stockwork zone in Tak-H area conatin 5 vienlets in square meter. Maximuni
. thickness of vienlets is 5 Cm . Host rock are meta-sediments and meta-subvolcanics Stockwork contain: Pyritc + Chalcopyrite? Magnetite? Sphaleritc? Galena with Chlorite + Quartz alteration in meta-sedirnents and Propylitic- silicification alteratior . in meta-gabbro- diorite to meta-diabase +Layered zone in Talc-Il area contain: Magnetite + Pyrite + Chalcopyrite
. Sphalerite + Galena )+ sulfosalts + Gold) with Chlorite +? Carbonate alteration + Major minerals within massive? zone are: Magnetite + Pyrite+ Chalcopyrite Sphalerite + Galena (+ sulfosalts + Gold) with Chlorite+ Carbonate alteration. Tak-II . has more sphalerite and Galena in comparison with Tak- I
Tak-I: % Cu=0.01-5.86, Zn = 269- 15600(ppm), Pb = 27- 4400(ppm),AL
- 58 = Bi = 34- 2200(ppm), and Mo د (ppm)= 0.86- 7.53 (ppm), Ag = 2.4- 95.l(ppm) 1300 (ppm) .
.33 . 0 Tak-lI:% Cu=0. 33- 2.56, % Zn = 0.3- 7. 68, Pb = 93- 5000 (ppm)? Au
. 11( ppm) Ag= 18.7- 105 (ppm) , Bi=79-214(pprn),andMo=54- 116(ppm)
Zn and Pb content of Tak-II is higher than Talc-I in three types of mineralization.
Based on lithology, style of mineralization, types of alteration, texture and geochemical, Taknar is Magnetite- rich Cu-Zn-Au-Ag-Pb massive sulfide deposit Using the paragenesis and mineral stable diagrams, Taknar ore bearing solution had :the following condition
)30-( -)29-( = fO2 و 7 -5 =Tak I: T ° C =270 °, pH )12-( -)1 1-( = pH => 5 - >9 , fO2 (-35)- (-38), log aS2 و Tak II: T 0 C=270 °
Tak-I formed at higher temperature, lower pH, and higher 102 than Tak-H .Tak-Il is part of later portion of Tak-IMagmatic activity has happened in Paleozoic, Mesozoic and Tertiary after polymetal mineralization (Ordovician ) . Some intrusives had ore bearing solution? Cu often) that it formed stockwork and veinlets mineralization. Intrusive rocks in Taknat zone arc divided in two groups based of regional metamorphism
1) middle-late Paleozoic intrusives are: meta-granodiorite porphyry, meta-biotite granodiorite porphyry, meta-granite porphyry, meta-gabbro-diorite porphyry ,metaquartz monzonite porphyry, spotted meta-quartz monzonite porphyry spotted meta-granite porphyry, and spotted meta-granodiorite porphyry with
quartz- sericite, sericite- some silicification, quartz- sericite- chlorite, and propilitic alteration.
2) Post Paleozoic intrusives are: quartz monzonite, quartz monzodioritc porphyry, quartz monzonite porphyry, granodiorite porphyry, granitc porphyry, graphic biotite granite, and graphic granite with quartz- sencite ,chlorite, quartz- sencite and quartz- minor sencite alteration
Stockwork mineralization observed in quartz monzonite and granite p orphyry in
NE of Tak-I. Mineralization consist of is quartz, secondary iron oxides and malachite Alteration are : quartz- sericite and quartz- sericite- chlorite alteration. The source of ore bearing fluid could be either the expose intrusives or some other intrusives at depth.

Third type of mineralization has formed along the faults. Epigenetic mineralization has happened at different stages. Argillic, silicification, and secondary iron oxides and malachite are common. Epigenetic mineralization in Tak-Il have higher Pb and Zn in comparison with Tak-I.

Subject List : polymetal deposit