Writers : Goharshahi,Rashin ; supervisor: S,Amini
Refference : M.Sc.Thesis _ Tarbiat modares;Tehran
Publishing Year : 1380

Abstract :

The Studied Granitoid, with the nearly extent of 48 km is located in the Sheshtmad geological sheet 1/100,000 wich is situated in the south of Sabzevar between North Latitude of 35, 45 to 36 and East Longitude of 57,30 to 57, 45 .Sheshtmad is a small port of North- Eastern of Central Iran wich is located between two main faults of daruneh end Binalud .This Granitoid pluton is in a district where the Ophiolites of upper Cretaceous of south Sabzevar have appeared Chronologically the oldest outcrop of district belong to the lower Cretaceous, and Quaterner deposits form the youngest ones. The volcanic units of the upper Cretaceous arid Eocene have spread in this region and in the order there are evidenes of subduction arid collision occurrence and the advent of Oceanic Island Arc.
Probably, in the Oligomiocene period, an interusive igneous phase having the main composition of Tonalit, Granodiorite arid less amount of Grant after the more basic and old igneous phase of microdioritic, neighboring unit, form the concerned Granitoid near Kuh-e-Mish Mountain, which is of type Calc Alcalen MetuAlumine to a little PerAlumine. The granitoid contacts are generally cross-cutting and they don't obviously have any heat mark due to intrusive hot granitoid magma on the sedimentary and volcanic rocks of the region However in its contact with microdiorit of kuh-e-mish mountion, the heat mark is seen as the formation of gradational sharpness and sinuous shape because of the interaction between the hot granitoid magma and the cool microdiorite host these findings are in accordance with the performed desert and petrography and geochemistry reserarches. Rgarding magmatic origin the concerned granitoid mass has possibly been a Real Hybrid. The approximate depth of its formation has been 73 km or more or less, arid its magma-tic stoping depth less than 5km.
Investigating the tectonic place of the concerning granitoid, we notice to the similar characteristics of it and VAG of the type Active Marginal Continental There are also evidences of collision with Oceanic Island Arc in Eocene arid the continuation of subduction after that. It is the probable occurrence of this phenomenon due to formation of normal VAG of the concerning magma, enters the position of post tectonic granite (POG).

Subject List : granitoide