Stylolite structures and Faults in the Bandwaya area at the western plunge of the Alqosh anticline in northern Iraq

The current study conducted of the faults and stylolite structures appearing in the Bandwaya resort, the overlapping area of Alqosh and Dehqan anticlines. The study was conducted in two locations: one represents Injana Formation, and the other is the contact area between Fatha and Pilaspi Formations. This is due to the abundance of tectonic stylolite in the contact zone between Fatha and Pilaspi Formations. They are associated with minor faults represented by slicken lines. The occurrence of both structures is linked to the presence of the basenal sinistral strike-slip fault that affected the area, as seen in satellite images. (ẟ1) direction refer to (N-S), (NE-SW) and (SW-NE) and little stylolite formed by vertical stresses. It has been also noted that the two structures appear independently in some layers, as there are layers containing only stylolite, and others containing only sheet of slicken lines. This prompted Author to investigate the reasons of this by studying the mechanical relationship between layers containing only stylolite and only slicken lines, by measuring the Schmidt rebound of each of these layers. Also, by studying the mineral components and extracting the ratio of insoluble components versus carbonate mineral (Acid Dissolution Method). The study showed relationship between the mechanical and brittle deformation behavior with insoluble contents and carbonate content in the layers containing only slicken lines and only stylolite, where the rock layers containing only stylolite exhibit lower Schmidt rebound and contain slightly higher insoluble residue than the layers containing only slicken lines.,,,