Writers : Safari, M.; Akbari Moghadam, M.
Refference : 28th Symposium on Geosciences and the 14th Symposium on Geological Society of Iran
Publishing Year : 1389

Abstract :

Kabudan map 1:25.000 is one of 16 sheets in Bardaskan map 1:100.000 that located in 270km SW Khorasane Razavi province. This sheet placed in central Iran zone and center of Alp-Himalaya belt and divide into 2 local structural zones include: Taknar in south and Sabzevar in north. These zones separated from each other by rivash or taknar fault and have two different tectonic regimes. Taknar granitoides subdivided into two varieties: Precambrian (include Bornavard granite) and Tertiary intrusive rocks (include gabbro, diorite, Gr that have composed of granodiorite to alkali granite). In the Sabzevar zone Cretaceous intrusive rocks cropped out. These intrusions include MOZ and Mgr. Taknar granitoides have meta-alumine, calco-alkaline and high potassium characteristics. These granitoides are very similar to cordilleran I-type and Lachlan fold belt granitoids. Whereas, Sabzevar granitoides have lowe potassium, meta-alumine, and tholeiitic characteristics and belong to plagiogranites. (La/Yb)N values in the Sabezvar granitoides are low and vary from 0.8 to 1.2. These values in the Taknar granitoids are higher and between 3.7 and 12. This indicates that Taknar granitoides have continental crust origin and Sabzevar granitoides have mantle origin. La in Taknar granitoides is between 20 and 30 ppm while in Sabzevar zone vary from 1.8 to 5 ppm. Large Ion Lithophile Elements (LILE) such as Ba, K, Ce are high in Taknar granitoids but Rb in Sabzevar granitoids is relatively higher. Nb element belongs to (HFSE) and Nd and Be elements are higher in Taknar granitoides. Sr and Rb are relatively higher in the Sabzevar granitoides that can be resulted from continental crust contamination. Low amounts of Nb (0.75 to 2) in Sabzevar zone granitoides also support continental crust contamination.

Subject List : Granitoeid