شواهد تواجد الفلدسبار في رمال تكوين الدبدبة جنوبي العراق في محافظة ذي قار

SOME EVIDENCE ON THE OCCURRENCE OF FELDSPAR MINERALS IN SAND DEPOSITS OF DIBDIBA FORMATION IN NASSIRIYA AREA, SOUTHERN IRAQ

Abstract Some sand samples bearing feldspar from dibdiba formation in Tell-Al- Laham area ( nassriya city) , southern Iraq were studied mineralogicaly , Geochemically and Petrographically to evaluated their contents of feldspar and Quartz.The grain size analyses showed that the Gravely sand deposits is mainly Composed of gravel , sand, sandy gravel and gravelly sand. The avearge content of very coarse and coarse sand fractions is making upto (27.54%) of the total deposits (0.063-2.00 mm) where as the medium and fine sand fractions make up (38.8%). The mean concentrations of Sio2 , Al2o3 , Cao , Na2o , K2o , Fe2o3 , and So3 are : ( 92.54 % , 2.08%, 1.01%, 0.56%, 0.9%, 0.38%, 0.63%) Respectively. Petrographic and Mineralogical studies revaled that all sand fractions (0.063-2.00mm) consist primarily of Mono& Polycrystalline quartz grains with small amount of rock fragments (6.25%) and some other impurities of secondary Gypsum.The avearge contents of feldspar minerals in sands of Tell-Al-Laham area is about ( 5.48%) including plajeoclase (Albite 1.1%) ,Alkali feldspar (orthoclase , Microcline & perthit 4.383%). All feldspar minerals were concentrated in a coarse & very coarse sand fractions of the deposits. There is a possibility to exploit the quarries of gravelly sand at the studies area for upgrading of feldspar ore by a froth floatation method.