The Salafchegan quartz diorite intrusion (Aleh Mountain) has intruded the sandy-limestone and sandstone of the Upper Red Formation as a con-cordant pluton and has metamorphed its country rocks slightly. The gentle dip of the sedimentary layering of country rocks suddenly increases near the pluton contact to a vertical position. This body has a circular shape, composed of quartz diorite and structurally could be divided into outer and central parts. While the outer part, with 500 meter thick-ness, shows alternation of leucocratic and melano-cratic layers, the central part has a massive outcrop. Both outer and central parts of this pluton show porphyritic texture typical of subvolcanic rocks. Moreover, the absence of ductile deformation within contact metamorphic aureoles, the presence of re-verse faults surrounding the intrusion, the occur-rence of concentric layering in the outer parts of the pluton, and the existence of magmatic foliation parallel to the contact zone in the outer dioritic layers could demonstrate ballooning mechanism in the Salafchegan intrusion. Accordingly, this pluton emplaced by ballooning mechanism due to repeated forceful injections of magma into an expanding shallow magma chamber, in the upper crust.