Abstarct: Davarzan- Kalate Sadat volcanic and volcanosedimentary rocks of Eocene to Oligomioceneand Quaternary sediments have been outcroped in south of Sabzevar ophiolitic belt and in the north margin of central Iran zone. The Middle- upper Eocene rocks of this area include a sequence of basic-intermediate lavas with trachyandesy basalt, trachyandesiteandandesite and their related pyroclastic rocks associated with sedimentary intercalations (tuff, berccia and Nummulitic limestone and sandylimestone)deposited inthe shallow depth marine environment. This sequence cut by trachyandesitic dikes. baxsed on the measured magnetic parameters, for one of these dikes with magnetic anisotroupy of susceptibility method (AMS) founded that the average of magnetic lineation trends correspond to the general azimuth of studied dikes. Oligocene detritalsedimantry rocks in Kalat-e-Sadat shows a few horizons of basaltic lavas, which already has been reported as quaternary basalts but new investigations indicate that they have been erupted in an Oligocene sedimentary basin. Oligocene volcanosedimentaryassociation has overlaid on the Eocene sedimentes and covered by Miocene gypsum bearings marls and Peliocene conglomerates.Eocenevolcanic rocks in Davarzan have porphyry, glomeroporphyry, microlitic, trachyitic and disequilibrium textures (such as reaction reams, inclusions, poikilitic textures and zoning in plagioclase andpyroxenes phenocrysts), and show continuity and differntional relation in geochemical diagrams. This subjectindicatesthat they evolved by fractional crystallization. Negative anomaly and enrichment ofHSFEsuch as Ti, Nb and Ta is one of the index characteristics of arc environments that is observed in thes rocks. They situated in magmatic arcs of continental margin on the tectonic setting discrimination diagrams. But Kalate- Sadat Oligocene volcanicrocks have the seme basaltic composition, enrichment from HSFEand in spite of Davarzan volcanic rocks they have not negative anomaly from HSFE or with low anomaly and in tectonic environment area situated in back arc basalts. Presenc of this charectrictics is the cause of continuity of subduction ofNeothetian oceanic slab beneath the margin of central Iran zone in Eocene which resulted in adjustment of fluids from dehydration of suducted oceanic slab and injection their fluids into upper mantel and mextasomatism. So Oligocene basaltic rocks in central Iran such as Kalat-e-Sadat however consisoin extentional back arc basin, but their inherited characteristic of back arc and subduction area.