The Tsaliet Group of Atsbi area is covered by widely distributed basement rocks ofrnboth metavolcanic and metavolcaniclastics rocks and Phanerozoic sandstone. Thernstudy area is represented by extensively exposed metavolcaniclastic rocks consistingrnof metabreccia, tuffaceous layers and slate units and metavolcanic rocks consisting ofrnmetabasaltic andesite and meta-andesitic units. These low grade rocks show N-Srnregional trend and they are presumably correlate with similar Neoproterozoic rocks ofrnArabian Nubian Shield.rnThe Atsbi area is one of the area where tectonic structures are recorded by the TsalietrnGroup that related to the collision history of ANS. Poly phase deformations in rocksrnof the study area are marked by the existence of different types of structural elementrnsuch as regional pervasive foliation, superimposed folds, various lineation and brittlernstructure such as joints. Two phases of ductile deformation (D1 and D2) and onernphase of brittle deformation (D3) are recognized. D1 deformation phase is related tornN-S compression that resulted in a pervasive foliation, sub vertical to vertical foldsrnand lineation whereas D2 deformation produced open, upright and harmonic lowrnplunging folds and lineation. The brittle structures such as joints that crosscut thernregional foliation represent the younger (D3) deformation phases of the area.rnField and petrographic observations show that the metavolcanic rocks are locallyrnaffected by propylitic alteration and sericitization. The metavolcanic rocks locallyrnexperienced pervasive silicification, sericitization, chloritization and epidotization.rnThe critical minerals such as tremolite/actinolite, epidote, chlorite, sericite, muscovite,rncalcite demonstrate lower green schist facies of metamorphism of the study area.rnThe geochemical result from the metavolcanic rocks of Atsbi area show a small rangernof composition indicating that they may have originated from a single,rnchemically uniform parent melt. The metavolcanic rocks are principally identifiedrnas low-silica andesite and only a few samples fall in the basaltic andesite field. Thernmafic/intermediate rocks also show predominantly calc-alkaline affinity and The Zr-rnNb-Y diagram shows that all the metavolcanic rocks lie within plume tholeiitesrnvolcanic arc basalt field.