بررسي توده نفلين سينيت رزگاه و واحدهاي رسوبي اطراف آن به جهت اكتشاف اورانيم تيپ رسوبي، آذربايجان شرقي

The Investigation of Razgah Nepheline Syenite and Its Marginal Sedimentary Units as a Sedimentary Uranium Mineralization in East Azerbaijan, Iran

Several important characteristics such as suitable parent rocks, hydrodynamics system for carrying uranium complexes and pervious sedimentary layers play key role for transportation and deposition of soluble uranium. In this paper, we present the results of investigations of parent rocks and host rock of sedimentary uranium in Razgah region to examine intrusive of nepheline syenite in Razgah together with surrounding sedimentary units with regard of sedimentary uranium mineralization. Razgah nepheline syenite located in the northwest of Sarab county in East Azerbaijan province in the north of Iran which covers an area of about 20 square kilometers. A sandstone unit spreads in the southeast of the area which was explorated as probable host rock of sedimentary uranium deposit. Radiometry survey of intrusive body and likely host sedimentary unit was done with scintilometer after examination of previous studies and field observations which showed radiation increment due to radioactive elements in both parts especially altered parts of the nepheline syenite body. Then rock samples were taken from highly radiation points in the nepheline syenite intrusive body and the likely host rock which results implying high content of uranium in the parent rock (Razgah nepheline syenite body) and concentration of this element in the host rock. Due to radiation increment to 2400 CPS in altered parts of the nepheline syenite body which involve uranium content of over 30 ppm and uranium content of 40 to 154 ppm in sedimentary host rock, it can be said that uranium content of Razgah nepheline syenite intrusive was transported during hydro dynamical and destruction process to the host sandstone unite that resulted in uranium enrichment. Investigation of the host sandstone unit extension and uranium grade in its various part requires more detailed exploration survey.