ويژگي هاي ساختاري شرق همدان

Geological Structures of Eastern Hamedan

The objective of this study is characterization of geological structures of eastern Hamedan in 34ʹ, 30- 34ʹ, 50ʹ(latitude) and 48°, 30-49°, 00ʹ (longitude). The study area is located in the northern part of the Sanandaj-Sirjan zone. This region has practiced both regional and contact metamorphisms due to the Late kimerian orogeny and intrusion of the Alvand batholith, respectively. The effects of the Late kimerian orogeny in this region includes: 1- Formation of the 2nd schistosity and lination in the regional metamorphic rocks. 2- Occurrence of the major faults and fractures (similar to the Zagros trend). 3 - Folding of strata. 4 - Recrystalization and foliation in the L. Cretaceous rocks (mainly the clastic parts) and 5- Intrusion of the quartz veins in the regional metamorphic rocks. Some fractures with different trends were formed as a result of the Alvand intrusion. After a gap in the sedimentation (Cretaceous - Oligocene) the Tertiary orogenies caused: 1 - Formation of younger faults and fractures, folding of Oligocene strata. 3 - formation of the younger schistosity and foliation in the regional metamorphic rocks.