Trace Element, Ni, PGE and Au Geochemistry of Sivas - Kızıldağ Ophiolites (Central Anatolia)
Abstract: The Kızıldağ (Sivas) Ophiolites, belonging to the Refahiye Ophiolitic Melange, generaly consist of wherlite oftransition zone, gabbros of mafic cumulate sequence and pyroxene gabbros, hornblende gabbros, microgabrointrutions, meta basalts and spilitic basalts. The ophiolitic complex is cut by Neogene magmatics, represented byaplite veins, granite, quartz monzonite and diorite as well as volcanic products such as andesite and basalt.Ni enrichment, up to 4630 ppm took place within the ophiolite bodies. Ore microscopy studies have revealed thatthe source of Ni is linneit, bravogite, gersdorfite, millerite, heazlewoodite and pentlandit e minerals. This studyreveals that Ni, occurring at levels of 0.2 to 0.3 % in primary ultramafic rocks, shows enrichments up to 0.46 %. It isbelived here that with more detailed studies, economical nickel deposits may be found. The ultramafic rocks in the investigation area show variable contents of Pt group elements comparition withprimitive mantle values. Os and Ru show enrichment, Ir, Rh and Pt show depletion, Pd shows both effects but withfew changes. Au, which is treated geochemicaly with Pt group elements, shows enrichment relatieve to primitivemantle values with few amounts. Comparision of Kizildag Ophiolites with N-Type MORE, the normalized values ofREE`s show generaly depletion except U and Ta. The Cl Chondrite normalized values of REE`s show differentpattern; Th, U, Ta, La and Ce show enrichment up to 10 times but Sr, Nd, Zr, Sm, Tb, Y, Yb, Rb and Ba showdepletion with different amounts.