THE INVESTIGATION OF RAZGAH NEPHELINE SYENITE AS A SUITABLE SOURCE ROCK FOR SEDIMENTARY URANIUM MINERALIZATION IN EAST AZERBAIJAN, IRAN

10th International Multidisciplinary Scientific GeoConference - SGEM2010, www.sgem.org, SGEM2010 Conference Proceedings/ ISBN 10: 954-91818-1-2, June 20-26, 2010, Vol. 1, 561-568 pp

ABSTRACT

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.

Keywords: sandstone type uranium, Razgah nepheline syenite body, radiation, scintilometer, East Azerbaijan