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The Darreh Bagh granitoid pluton (DGP), with middle Jurassic age (178 Ma), located in the northwest of Aligudarz city. The pluton is mainly granodioritic composition which emplaced in metapelitic rocks of Sanandaj-Sirjan structural zone. For the first time, the emplacement mechanism of this pluton, investigated by anisotropy of magnetic susceptibility (AMS) method. Based on the present investigations, the mean magnetic susceptibility, in terms of µSI for the studied rock groups are as follow: granodiorites (257), leucogranites (47), high tourmaline leucogranites (148), low tourmaline leucogranites (48), migmatites (437), surmicaceous enclaves (386). Considering the obtained values, the felsic part of the DGP belongs to the paramagnetic granitoids (500>km>0 in µSI) (equal to ilmenite series or S-type). Based on the magnetic parameters and their interpretations it is possible to divide DGP into the A and B domains and A1, A2 subdomains. The magnetic lineations in the subdomains oriented to the north. Whereas in the middle part of the pluton (B domain) it oriented dominantly to the east and southeast. Based on distribution patterns of magnetic lineations these domains were emplaced with a short delay compared to each other. Meanwhile, A domain was emplaced prior to B domain. With attention to distribution patterns of magnetic lineations and foliations, the principles of interpretation of magnetic parameters and regional geological characteristics, the Darreh Bagh granitoid pluton was emplaced in the form of a relatively large sill in a dextral shear zone (related to a transpression regime). [ABSTRACT FROM AUTHOR]

Zafarghand granitoid pluton with approximately 80 Km in the extent with early to middle Miocene age cropped out in 35 Km of SE Ardestan. The pluton composed mainly of gabbro to tonalite and intruded in the Eocene volcanic and volcanosedimentary rocks of Uroumieh-Dokhtar structural zone. For the first time, variations of anisotropy of magnetic susceptibility in Zafarghand granitoid pluton have been investigated by using anisotropy of magnetic susceptibility (AMS) method. Based on obtained data, the measured mean magnetic susceptibility values (Km in µSI) of the different rock groups of Zafarghand pluton are as follows: gabbros (32536), diorites (23768), granodiorites (18436), granites (8068) and tonalites (68). Therefore, the Km values decrease from grabbros and diorites to granodiorites, granites and tonalites. Gabbros and tonalites have the highest and the lowest Km values, respectively. The measured Km values indicate that, the studied granitoid belongs to ferromagnetic type (according to magnetite series and I-type granitoids). [ABSTRACT FROM AUTHOR]