The study area is located at the center of the Lut area and the southern part of the Eocene- Oligocene Lut volcano-plutonic belt. The main exposed igneous rocks include widespread and thick units of Middle Eocene volcanic (basaltic andesite, andesiteand trachy-andesite) and Eocene-Oligocene volcanic-subvolcanic (dacite and rhyodacite) with related tuffs, intruded by microdioritic stock and dykes of Oligocene with g abbrodiorite to quartzdiorite compositions. Texture is dominantly porphyritic and the main minerals are plagioclase, clinopyroxene, hornblende, K-feldspar, quartz and minor amounts of biotite with apatite, zircon, rutile and opaque minerals as accessory phases. These rocks with predominant K-high calc-alkaline to shoshonitic affinities, are I type and metaluminous and are characterized by LILE, LREE and Th enrichment relative to HFSE, depletion in Nb, Ti, Ta and weak depletion in HREE and Y. These features are characteristic of the post-collisional calc-alkaline rocks along with a continental active margin tectonic setting. In spite of the low ratios of Nb/U, Nb/La and Ce/Pb, the Sm /Yb (1.6-2.1) ratio reveals low contamination of magmas with relatively thin crust which is in accordance with low crustal thickness in this area (36-38Km). According to geochemistry of trace elements and REEs, the main cause of magmatism in Mahour was melting of a metasomatized lithospheric mantle (E-MORB like) with spinel lherzolite composition accompanied by very small amount of garnet in the presence of phlogopite. On the basis of the phenocrysts assemblage, REE pattern with negative Eu anomaly (Eu/Eu*=0.63-0.9) and also La/Yb calibration to crustal thickness, magmas have undergone relatively dry crystallization in the magma chamber at shallow depths (<40 Km). Non-equilibrium textures, multiple element and REE pattern, abundances of Y and K2O/Na2O in Mahour igneous rocks show contamination and mixing with acidic magma of amphibolitic lower crust due to temperature of mantle magma and AFC process played important roles in magma evolution, in addition to fractionation. La vs. La/sm diagram and Nb/Ta=10-13.3 illustrate partial melting and the role of lower crust in magma evolution, respectively. The presence of hornblende more than biotite, mantle-crust source, the contents of Sr, Rb, Ba, Ce and Rb/Zr, the tectonic setting discrimination diagrams and the regional geological evidences such as closing age of Neotethys, Naeen-Baft and Sistan oceans and cutting ophiolitic mélange by Eocene lavas around Birjand, all indicate Tertiarymagmatism in the Mahour area and therefore Lut in a post-collision tectonic setting. Calc-alkaline affinity and subduction geochemical signature in these rocks are related to metasomatized mantle source inherited from the low-angle subduction of Arabic plate (Neotethys oceanic crust) beneath the Central Iran plate in Mesozoic. The Probable mechanism for this magmatism is slab retreat and extentional collapse after orogenyin which Nehbandan and Nayband streak-slip and shear faults activities and also crust thickness had important role in emplacement of them. The igneous rocks have been affected by hydrothermal alteration. Zinc and copper mineralization formed as veins, veinlets and space filling among breccia fragments in fault crushed zone and predominantly in dacite-rhyodacite unit.