Petrology and geochemistry of isolated diabasic dikes in North Nain Ophiolite

Subject Areas :

Mohammad Fodazi ¹ , M.H Emami ² , سلیمان Alaei-Mahabadi ³

1 - دانشآموخته دکترای واحد علوم و تحقیقات دانشگاه آزاد اسلامی واحد علوم و تحقیقات
2 - عضو هیئت علمی دانشگاه آزاد اسلامی واحد اسلامشهر
3 - کارشناس ارشد سازمان زمین شناسی و اکتشافات معدنی کشور

Received: 2016-09-06 Accepted : 2016-09-06 Published : 2010-06-22

Keywords: Diabasic dikes, RodingiTes dikes, AmphiboliTes, Hydro Thermal Metamorphism,

Abstract :

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 theophiolitic suite is upper cretaceous and early paleocene based on microfossils found in pelagiclimestones[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 enrichmentis attributed to its differentiated origin. Geochemistry of trace elements and REE of these rocksand low(La/Y)N<1.5 and (La/Sm)N<1.5 ratios are similar to those of N-Morb to T-Morb in uppercretaceous.