پترولوژي متاولكانيكهاي پالئوزوئيك منطقه پل‌خاوند (جنوب شرق انارك، استان اصفهان)

In the Pol-e-Khavan‎d area (southeast of Anarak, Isfahan province, Iran), metabasite rocks associated with metasediments including slate, phyllite, schist, gneiss an‎d quartzite, are exposed in the Lak Mountain. Metapelites are the overlying rocks of the metabasites, which are metamorphosed in P-T condition of blue schist an‎d then green schist facies. The Anarak ophiolitic is older than the Anarak metamorphics an‎d metabasites in this region. This ophiolitic complex is overlained by Paleozoic an‎d Lower Mesozoic metamorphic rocks (schist an‎d marble). The presence of ophiolites belong to the Paleozoic in this part of the Yazd block is evidence of the Paleo-Tethys Oceanic crust existence in the interior parts of the Central- East Iranian Microcontinent. Microscopic studies show that the main textures of these metabasite rocks are porphyroblastic, granoblastic, poikiloblastic, lepidoblastic an‎d nematoblastic. These rocks are composed of plagioclase, clinopyroxene an‎d amphibole as the main minerals an‎d titanite, muscovite an‎d opaque as the minor minerals. The whole rock geochemical analysis of the metabasites indicate their basaltic an‎d an‎desitic basalt composition. They are peraluminous to metaluminous in nature an‎d belong to the low-potassium tholeiitic series. The chondrite an‎d the primitive mantle normalized diagrams indicate their enrichment. The main geochemical characteristics of these rocks are LREE enrichment relative to the HREE, LILE enrichment an‎d negative anomalies of Ti, Nb an‎d Ta (TNT). These geochemical features an‎d discrimination diagrams suggest that they are subduction-related, an‎d produced by partial melting of a lithospheric mantle spinel lherzolite in a back arc tectonic setting (BABB).

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