Iraqi National Journal of Earth Science

      This study focuses on the mineralogy and geochemistry of the limestone unit of the Qulqula Formation (Early Cretaceous). The age and stratigraphic position of this formation are controversial because of insufficient studies and the complex structure of the occurrence area. Twenty samples were selected and analyzed which represent six sections: Sarkan, Awera, Griana1, Griana2, Hawar, and Hawara Kon at the Mount of Shenrui in Halabja area located in Kurdistan Region, northeastern Iraq near the Iraqi-Iranian borders. The mineralogical study by the X-ray diffraction technique shows that the samples are composed of 70.14 % calcite, and 28.07% quartz. The geochemical analysis shows that CaO is abundant in most of the studied samples, the increases of (SiO₂, Al₂O₃, Fe₂O₃, TiO₂, and K₂O), and the decrease in (CaO and MgO) leads to the change of limestone to siliceous type. The limited dolomitization can be confirmed by the low concentration. The component Sr has a negative correlation for both major and trace elements. On the other hand, (Cr, Co, Ni, V, and Zr) have a positive correlation with (MgO, Fe₂O₃, SiO₂, Al₂O₃, K₂O, and TiO₂), thismay indicate the effect of the basic rocks in surrounding areas enriching limestone with these elements.

Five ostracode species have been described from Baluti Formation (Upper Triassic) of North Iraq, these are Fabanella A , Hungarella moorei (Jones)-Anderson, 1964, Ogmoconcha cf. blakei (Sohn, 1968), Ogmoconcha bristolensis (Anderson, 1964), Cytherella acuta Urlichs, 1972.تم وصف خمسة أنواع من الأوست ا رکودا من تکوین بموطی )الت ا ریاسی الاعمى(، وهذه الأنواع هی:
Fabanella A , Hungarella moorei (Jones)-Anderson, 1964 , Ogmoconcha cf. blakei (Sohn,1968), Ogmoconcha bristolensis (Anderson, 1964), Cytherella acuta Urlichs, 1972.

Five ostracode species belong to the genus Poloycope have been described from Baluti Formation (Upper Triassic) of North Iraq, these are: P. aghdarbandensTollman 1991, P. bourquinaeCrasquin and Gradinaru 1996, P. spp. Forel and Crasquin 2011, P. sp.A Rosenfeld and Honigstein 1998 and P. sp. Monostori 1996:
P. aghdarbandens Tollman 1991, P.bourquinae Crasquin and Gradinaru 1996, P. spp.Forel and Crasquin 2011, P. sp.A Rosenfeld and Honigstein1998 and P. sp. Monostori 1996.