S Hassanpour; S. Alirezaei
Abstract
The Masjeddgaghi Cu-Au deposit is located to the southeast of the Arasbaran zone, NW Iran, to the south of the Lesser Caucasus. Mineralization in Masjeddaghi is associated with an Eocene dioritic subvolcanic pluton intruded into older volcanic and sedimentary rocks. The Masjeddaghi intrusive body is ...
Read More
The Masjeddgaghi Cu-Au deposit is located to the southeast of the Arasbaran zone, NW Iran, to the south of the Lesser Caucasus. Mineralization in Masjeddaghi is associated with an Eocene dioritic subvolcanic pluton intruded into older volcanic and sedimentary rocks. The Masjeddaghi intrusive body is high-K, calc alkaline, and meta-aluminous, and formed in an island arc subduction/collision setting. Hydrothermal alteration is distinguished by a potassic core marked by secondary biotite and K-spar that grades outward into a chlorite-rich propylitic halo. The ore minerals include chalcopyrite, associated with minor chalcocite, bornite, tetrahedrite, and trace molybdenite. Pyrite and magnetite are common associates. The Masjeddaghi deposit is elliptical in plan view, 500 x 400 m in diameters, and mineralization has been traced for several hundred meters from surface exposures. 40Ar/39Ar geochronology on secondary biotite from potassic alteration zone indicates that mineralization, and by corollary, the emplacement and crystallization of the Masjeddaghi porphyritic intrusion, occurred in 54.07 ± 0.53 Ma. The Masjeddaghi ore deposit shows geology, mineralization and alteration characteristics comparable to those typical of island arc type porphyry Cu-Au systems. Masjeddaghi ore deposit shows geology, mineralization and alteration characteristics similar to island arc porphyry type systems.
A. Akbarpour; N. Gholami; A. Saiedi
Abstract
The masjeddaghi area with 8.5 km2 extent is located in 35 km for east of jolfa.The geological exploration started in this area in 2003 and soil sample method was chosen due to the geological situation topography and weathering ,The sampling network was 100m*100m and 100m*200m ...
Read More
The masjeddaghi area with 8.5 km2 extent is located in 35 km for east of jolfa.The geological exploration started in this area in 2003 and soil sample method was chosen due to the geological situation topography and weathering ,The sampling network was 100m*100m and 100m*200m and all samples were analyzed for 13 elements .including Au,Cr,Co,Ba,Cu,Pb,Zn,Ag, Be, Mo,Sn,Mn.The geological studies shows that the oldest rock unit outcropped is Eocene flysh widely distributed in southern and north eastern part of the area .Another outcrops are mainly volcanic ,subvolcanic complex of andesite and trachyandesite, quartz monzonite and agglomerate(oligomiocene).
In this area brecciated veins of barite – silicious and Cu,Pb,Zn sulfids and various pyrite type of mineralization have been identified. data processing have been carried out for analytical results(comparing main and duplicated samples data),and indicate normal distribution for Ni,Be ,Mn log distribution for other elements.That these two analysis method s,factor analysis and correlation matrix analysis (using standardizing the datas (x-x/s))have been consictent.
Regarding The composite haloes,the result of studies indicate Au,Ag,Be anomalies in eastern part of the area and Cu,Mo anomalies in western part of ARPACHAI valley. considering the lithology and its relation to geochemical anomalies of the area, probable presence of porphyric Cu mineralization in eastern part and epithermal high sulfide Au mineralization in quartz-barite veins are identifid,
A. Akbarpour; A. Rasa; M. Mehrpartou
Abstract
The Masjeddaghi area is a part of Alborz-Azarbaijan Zone and located in the Jolfa 1:100000 geological map sheet. The oldest rock units cropped out widely in the south and northeast of the area belong to the Eocene flysch-type sediments. The other outcrops consist mainly of volcanic rock complex of andesites ...
Read More
The Masjeddaghi area is a part of Alborz-Azarbaijan Zone and located in the Jolfa 1:100000 geological map sheet. The oldest rock units cropped out widely in the south and northeast of the area belong to the Eocene flysch-type sediments. The other outcrops consist mainly of volcanic rock complex of andesites and trachyandesites affected by quartz monzonite intrusion and caused alteration of phyllic and carbonate phyllic type. The mineralization in volcanic complex is also accompanied by quartz and barite veins. The study of alterated zone around veins shows sericite, silicified, prophillitic, chloritic and alunite (jarosite) alterations. Investigation of alteration zones around mineralized veins shows epithermal gold ore in which alunitic alteration (jarocite) is the most important characteristics. The result of the study on alteration and extension of altered zones in the whole study area give rise to the probability of porphyry type copper deposit (potassic, phyllic, argillic and prophylitic alteration zone).
