plagioclase, ± pyroxene, ± epidote, ± chlorite ±, sphene and opaque minerals. Chlorite and prehnite are secondary minerals, observed as commonly veins in the ...
GEOLOGICAL AND GEOCHEMICAL CHARACTERISTICS OF THE METAMORPHIC SOLE AND DOLERITIC INTUSION ROCKS IN A LATE CRETACEOUS ACCRETIONARY COMPLEX (ARTOVA, TOKAT NORTHERN TURKEY) 1
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RAHMİ MELİH ÇÖRTÜK , ÖMER FARUK ÇELİK , MUTLU ÖZKAN , İSMAİL EMİR ALTINTAŞ 2 GÜLTEKİN TOPUZ
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ABSTRACT
Different types of metamorphic rocks from different metamorphic facies in the İzmir-Ankara-Erzincan suture zone are observed as approximately east-west trending out crops, near Artova (Tokat) and surrounding areas. The metamorphic rocks in the Artova accretionary complex represented by amphibolite, garnet-micaschist, chloriteschist, calcschist, andmarbles, which were metamorphosed under the greenschist and the amphibolite facies metamorphism. The metamorphic rocks are tectonically located beneath the ultramafic rocks. Both the metamorphic rocks and the ultramafic rocks have foliations which are parallel to each other. Ultramafic and metamorphic rocks are crosscut by dolerite/gabbroic rocks, which their thickness are up to 10m. Amfibolites, which have nematoblastic and granoblastic texture, are composed of amphibole, plagioclase, ± pyroxene, ± epidote, ± chlorite ±, sphene and opaque minerals. Chlorite and prehnite are secondary minerals, observed as commonly veins in the rock texture. According to whole rock major, trace and rare earh elements geochemistry, amphibolites were occured in E-MORB and OIB tectonomagmatic environment.The dolerite dykes, cross cutting ultramafic and metamorphic rocks show the granuler and the sub-ophitic texture. They consist of plagioclase, amphibole, ± pyroxene, ±, sphene and opaque minerals. Chlorite, calcite and prehnite are the secondar yminerals in the dolerites. Dolerites exhibit flat pattern in the chondrite normalized REE diagram. They show LIL element (eg. K, Rb, Sr)enrichment and the HFS (eg. Nb,Ta) depletion in the N-MORB normalized diagram, suggesting existence of subduction component during their occurences. The metamorphic rocks located in the Artova accretionary complex were interpreted to be the metamorphic sole rocks which are occured in the intra-oceanic subduction processes because they are tectonically located beneath the ultramafic rocks and the dolerite dykes cross cutting the metamorphic rocks are in tholeiitic character. Finally these rocks were tectonically incorporated into the Late Cretaceous accretionary complex. This study was funded by TUBITAK (Project no:112Y123).
Keywords: Metamorphic sole, amphibolite, accretionarycomplex, geochemistry
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Jeoloji Mühendisliği Bölümü, Kocaeli Üniversitesi, 41380, Kocaeli, Türkiye İstanbul Teknik Üniversitesi, Avrasya Yerbilimleri Enstitüsü, 34469 Maslak, İstanbul
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