Sedimentology
hajar ghafleh maramazi; Fardin mousivand; alireza zarasvandi
Abstract
The Gol-e-Zard zinc-lead deposit is located in the Malayer-Isfahan belt of Sanandaj-Sirjan zone in northeast of Aligudarz, Lorestan province. Mineralization occurred as two different ore horizon within metamorphosed Jurassic shale and sandstone. Generally, two ore facieses were distinguished in the deposit: ...
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The Gol-e-Zard zinc-lead deposit is located in the Malayer-Isfahan belt of Sanandaj-Sirjan zone in northeast of Aligudarz, Lorestan province. Mineralization occurred as two different ore horizon within metamorphosed Jurassic shale and sandstone. Generally, two ore facieses were distinguished in the deposit: 1) vein-veinlet/stringer facies, and 2) bedded facies. Primary minerals of the ores involve pyrite, sphalerite, galena and chalcopyrite, and the secondary minerals include cerussite, smithsonite, azurite, malachite and goethite. The gangue minerals are quarts, chlorite, calcite and clay-mineral. In the stringer facies, chalcopyrite replaced mainly pyrite and other minerals indicating influx of a copper-rich hot fluid influx into a pyrite-rich ore called as “zone-refining process”. In the Gol-e-Zard deposit metal and mineralogical zonation was observed. Alteration zones have distinct pattern, silicic-carbonatic at core to chloritic at margins. Based on textures and structures, mineralogical, ore facies, alterations and geochemical characters, the zinc-lead mineralization in the Gol-e-Zard region is of Selwyn-type sedimentary-exhalative (SEDEX) deposits, deformed and metamorphosed by the Late Cimmerian and Laramid Orogenies at green schist facies.
M. Sadeghian; M. Sheibi; S. Badallo
Abstract
The Gol-e-Zard granitoidic pluton with an age of ~ 165±5 Ma is located in the north of Aligoudarz city, Lorestan province, in the Sanandaj-Sirjan structural zone. The pluton intruded into the late Triassic-early Jurassic slates, phyllites and micaschists. The granodiorites, dominant rock types ...
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The Gol-e-Zard granitoidic pluton with an age of ~ 165±5 Ma is located in the north of Aligoudarz city, Lorestan province, in the Sanandaj-Sirjan structural zone. The pluton intruded into the late Triassic-early Jurassic slates, phyllites and micaschists. The granodiorites, dominant rock types of the pluton, are cut by the leucogranites, aplitic veins, pegmatites and gabbro-dioritic dykes. The S-type nature of the Gol-e-Zard granite is evidenced by the presence of metaplitic enclaves (surmicaceous and andalusite-sillimanite hornfels), silica enclaves, andalusite and garnet xenocrysts and silica veins relicts. The anisotropy of magnetic susceptibility (AMS) method was used to investigate the mode of emplacement. The total numbers of 868 oriented core samples were analyzed for magnetic susceptibility. The obtained mean susceptibility (Km) in µЅІ was 227, 57 and 585 for granodiorites, leucogranites and gabbrodiorite dykes, respectively. The low Km values (
