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The Mesozoic Bazman granitoids are located in Sistan and Baluchestan province, southeastern Iran. Geology of the study area consists of Carboniferous shale, sandstone, and limestone and Permian siltstone, shale, sandstone, limestone, and dolomite that were intruded by the Bazman granitoids. These granitoids include various phases of granite, granodiorite, quartz-monzodiorite, monzodiorite, diorite, and gabbro. They are metaluminous to slightly peraluminous, reduced, calc-alkaline and I-type, and display geochemical characteristics of continental margin (ensialic) granitoids. In this paper, field, petrography, and geochemical data were used to discriminate the Bazman granitoids either as productive or barren granitoids. Although there are a few skarn-related mineral occurrences adjacent to the Bazman granitoids, most exposed intrusions are not hydrothermally altered and mineralized. Rb/Sr, Zr/Hf, and K/Rb ratios indicate that the granitic magmas that formed most of the Bazman granitoids indicate that they are moderately evolved and have generally not undergone post-magmatic hydrothermal activity. The Sm/Eu and Rb/Ba ratios and the concentrations of Rb, Ba, and Sr within the aforementioned granitoids show that the rocks are similar to the averages of granitoids devoid of Li, Be, U, Sn, W, and Ta deposits. The I-type arc characteristics and other geochemical features of the Bazman granitoids show that they are not typical of parental magmas to Sn, W, Mo, and Zn mineralization, but are mainly fertile for Cu and Fe (Au) skarn-related granitoids.

IntroductionThe Lar Cu-Mo prospect located 22 km north of Zahedan, southeast Iran, at the border with Pakistan and Afghanistan is proximal to Saindak and the giant Reko Diq copper deposits of Pakistan (Figure 1a). The Lar Cu-Mo prospect mainly occurs in syenitic to monzonitic igneous rocks of the Lar igneous complex (LIC). Although the LIC has been subject of several petrological and geochemical studies (

The Bazman granitoid complex (BGC), including a large zoned pluton, intrudes into the upper Paleozoic sedimentary cover of the Lut block. It crops out on the southern slope of the Bazman volcano in Baluchestan Province of Iran. The intrusive rocks range from gabbro to various metaluminous to weakly peraluminous granites, and they are classified as I-type magmatic series. They display geochemical characteristics of typical volcanic arc magmatism at continental margins. Major-and trace-element variation diagrams show that fractional crystallization was the major process and crustal contamination, a subordinate process during the evolution of the BGC. The decrease in CaO, MgO, Al 2 O 3 , Fe 2 O 3 , TiO 2 , P 2 O 5 , and Sr, as well as the increase of K 2 O and Rb with increasing silica, are possibly related to the fractionation of plagioclase, hornblende, apatite, and titanite, whereas the increasing K, Rb, Cs, Pb, and light rare earth elements (LREEs) can be explained by crustal contamination. The BGC rocks are enriched by large ion lithophile elements (e.g., Rb, K, Cs) and the LREEs with respect to the high field strength elements (e.g., Zr, Hf, Nb, Ta, Y) and heavy rare earth elements. New ID-TIMS U-Pb dating performed on zircon and titanite extracted from the granitic samples indicates that the BGC was emplaced during the late Cretaceous period at 83-72 Ma by subduction of the Neo-Tethyan oceanic crust beneath the Eurasian continent. Subsequently, the complex became part of the Lut block when it probably rotated counter-clockwise with respect to the Sanandaj-Sirjan zone and the Urumieh-Dokhtar volcano-plutonic belt.

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