چكيده لاتين :
The Jurassic volcano - sedimentary complex in the Zagros Mountains within the central part of the Sanandaj- Sirjan structural zone is composed of volcanics (basalts andesitic basalts and andesites),
subvolcanics (dolerites and microdiorites), volcaniclastics (tuffs, lapilli tuffs, agglomerates, pyroclastic and hyaloclastic breccia and tuffites). The igneous rocks with calc-alkaline to tholeiitic affinity were erupted in a subduction environment. The volcano sedimentary complex has been affected by hydrothermal alteration.
Hydrothermal minerals have replaced primary rock components (selective pervasive) or have occurred as vein and vesicle fillings (non pervasive). There are three alteration zones in the study area including, propylitic (chloritic), sericitic and intermediate argillic based on variate amounts of the chlorite, epidote, clinozoisite, calcite and illite. In spite of plagioclases, primary clinopyroxenes and amphiboles are wholly or partially preserved. The propylitic (chlorite) zone is enriched in Y and HREE especially Ho, Er, Tm and Tb relative to fresh rocks and altered rocks in another alteration zones. The intermediate argillic zone is enriched in V relative to fresh rocks and altered rocks in another alteration zones and depleted in Au relative to fresh rocks.
