Petrology and geochemistry of isolated diabasic dikes in North Nain Ophiolite

Nain ophiolites,which are part of Ophiolitic suite of western margin of Central Iran micro continent, covering 500 km2 crop out along Nain-Baft fault. The age of the emplacement of the ophiolitic suite is upper cretaceous and early paleocene based on microfossils found in pelagic limestones[1]. Diabasic dikes have been divided into microgabbro-gabbros, gabbros with hydrothermal metamorphism, rodingites, and amphibolites, based on hydrothermal metamorphism, metasomatism, and tectonic events that they have gone through[2]. These rocks have tholeit character in geochemical diagram(AFM), and the chondrite normalized spider diagrams shows enrichment in LREE and HREE. This enrichment is attributed to its differentiated origin. Geochemistry of trace elements and REE of these rocks and low(La/Y)N<1.5 and (La/Sm)N<1.5 ratios are similar to those of N-Morb to T- Morbin upper cretaceous.