Fibrous Gypsum Veins Development in Southern Himrin Mountain, East of Iraq

الملخص

           Fibrous gypsum veins development in claystone host rock has been studied in southern Himrin Mountain area, northeast Miqdadiya east of Iraq. Three groups of veins have been recognized: (1) Simple fibrous veins, which contain perpendicular or inclined fibres to vein walls, their straight fibres extend between vein walls and these veins were affected by one opening direction, (2) Moderately complicated fibrous veins, which contain curving fibres either at vein walls or at vein centre. These veins were affected by two different opening directions, and (3) Complicated fibrous veins, which contain multicurved fibres in different places. These veins were affected by more than two different opening directions.