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Home , Chromite, Economic geology, Islahiye

The and Chemistry of the Deposits of Southern (Kızıldağ, Hatay and Islahiye, Antep) and Tauric Belt (Pozantı-Karsantı, ),

M. Zeki Billor1 and Fergus Gibb2 1 Visiting researcher, Department of Geoscience The University of Iowa Iowa City, IA 52242, USA (Permanent address: Çukurova University, Department of , 01330 Adana, Turkey) 2 Department of Engineering Materials, University of Sheffield, Sheffield, S1 3JD, UK e-mail: [email protected]

Introduction recognized in Turkey are: a) the southern (peri- The Tethyan ophiolite belt is one of the Arabic) ophiolite belt, b) the Tauric (median) longest ophiolite belts in the world, extending from ophiolite belt, and c) the northern ophiolite belt. Spain to the Himalayas. The , genesis In this study, chromite deposits from the and geological time scale of the ophiolite belt southern and Tauric ophiolite belts have been varies from west to east. It shows its maximum studied. In the study area, the Southern and Tauric development in Turkey. The tectonic setting of the have more than 2000 individual chromite Turkish ophiolite belt is a direct result of the deposits throughout the ophiolite; geographically, closure of the Tethyan Sea. the chromite pods are clustered in four locations: Ophiolites in Turkey are widespread from the Karsantı and Gerdibi-Cataltepe districts in the west to east and show tectonically complex Tauric ophiolite belt and the Hatay and Islahiye structures and relationships with other formations area in southern ophiolite belt. and geological units. The three ophiolite belts

B l a c k S e a

Sinop

t h A n r o t o o l i a N North Anotoliann Fa Fault u l t

Bursa Kopdagi Ank a ra Harmancik 5 Er zincanErzincan Orhaneli Eskisehir Balikesir Divrigi 4 Elazig 1 Lake Van Agri Pinarbasi Bitlis SaridagSoridag Izm ir 3 Ay din Konya Denizli Poturge Beysehir Pozanti 6 Mugla Ma ras 2 Antep Antalya Mersin Koycegiz Islahiye Adana

Antakya Fethiye 0 100 km Mediterranean Sea

The three main ophiolite belts in Turkey are: Location of some Chromite areas: The norhern ophiolitic belt (Izmir-Bursa-Ankara-Erzincan-Erzurum) 1 Guleman-Elazig region 2 Fethiye and Koycegiz Areas The median ( Tauric) ophiolite belt 3 Pozanti-Karsanti Area (Mugla-Antalya-Beysehir-Mersin-Pozanti-Pinarbasi-Erzincan 4 Bursa and Eskisehir Areas The southern (peri-Arabic) ophiolitic belt 5 Kopdagi Area (Antalya-Elazig-Soridag-South of Lake of Van) 6 , Islahiye and Maras areas

Figure 1. Distribution of ophiolites and main chromite districts in Turkey (Modified from Engin et al., 1986). . Podiform chromite ore bodies in different During the detailed microscopic study of the shapes and sizes (potato, pipe, pod, tabular, folded chromite samples (PGM), and etc.) can be seen at different stratigraphic levels of sulphides were also observed. the harzburgites of the ophiolite. Podiform ore bodies are affected by plastic deformation during Pozantı-Karsantı area (Tauric ophiolite belt) forming of pods and also by different degrees of The Mesozoic age Pozantı-Karsantı tectonic deformation during and after emplacement. ophiolite is located 60 km north of Adana. The The chemistry of the chromite grains was ophiolite extends in a northeasterly direction for determined using a wavelength dispersive more than 100 km with an average width 20 km microprobe. and metal standards were between the towns of Pozantı and Faraşa. used to analyze the following elements Cr, Al, Fe The autochthonous Mesozoic platform (total), Mn, Mg, Ni, Co, V, Ti, Si. Fe2+, Fe3+ have , belonging to the “Tauric limestone been calculated based on 24 cations using spinel axis” have a tectonic contact with the Pozantı- stoichiometry Karsantı ophiolite. The ophiolite sequence consists of tectonites and cumulates. The harzburgite has Hatay and Islahiye area (Southern ophiolite been affected by asthenospheric plastic flow during belt) spreading. Non-deformed layered cumulates are The southern belt, geographically enters represented by , clinopyroxenite, layered Turkey from the north of (Baer-Bassit area) and quartz diorites and extends from Antakya to Elazığ Soridağ. It The Pozantı-Karsantı ophiolites contain enters (Zagros range) through Oman (Oman about 1000 individual chromite deposits. The ophiolite). It incorporates some of the most well chromite pods are clustered in two locations: a) the known ophiolite complexes, such as the Troodos Karsantı district to the north east, and b) the (Cyprus), Kızıldağ (Turkey), and Semail Nappes Gerdibi-Cataltepe district in the south west. The (Oman). The allochthonous Kızıldağ ophiolite chromite ore bodies occur in both the harzburgite exposes the complete ophiolite sequence. cumulate parts of the ophiolite. Aproximately 200 economic scale Two types of chromite mineralization have individual podiform chromite ore bodies are been determined: a) Podiform chromite bodies (in observed on Kızıldağ Mountain (Kızıldağ ophiolite) dunitic pockets) inside the harzburgite and b) and Balıkalan, Türkoğlu Village (Islahiye stratiform chromite deposit in non-deformed ophiolite). Generally the podiform chromite bodies cumulate zones above the transition zone and are clustered near the cumulate/harzburgite within the - sequences. This latter boundary. deposit (Kızilyüksek) occurs as rhythmic The pods are composed of interlayering of chromite and dunite layers and it is spinel and . The chromite mineralization has economically important. different textures which reflect depositional The different sizes of the dunitic pockets conditions. The textures are nodular, banded, and chromite pods seen in the transition zone are disseminated (coarse and fine grained) and massive. concordant or sub concordant to the . Electron microprobe analyses have been carried out The upper part of the transition zone of the on from the Kızıldağ and Islahiye areas. Pozantı-Karsantı ophiolite is rich in dunite (300- The chromites from the Kızıldağ and 500 m.). The dunitic part of the transition zone is Islahiye ophiolites exhibit a wide compositional the most affected part and records strong high range of Cr2O3, Al2O3, Fe2O3, FeO, MnO. The temperature plastic deformation. This section chromites from the Kızıldağ ophiolite have higher exhibits layering parallel to the foliation of the Cr2O3 and lower Al2O3 than the Islahiye chromites. harzburgites due to the deformation. This is the The results of geochemical analyses of the Kızıldağ main factor which differentiates the dunite of the and Islahiye chromites have been projected in the transition zone from the dunite of the cumulate unit. spinel prism to show the variation and the changes The layers and dikes (1-10 cm of chemical composition which is typical for width up to 10 m. long.) are observed infrequently podiform chromites. within the dunitic parts and granoblastic harz- The chromites from the Kızıldağ and burgites, respectively. Islahiye ophiolites show similar chemical Electron microprobe analyses have been characteristics to the chromites from the Troodos carried out on chromites from the Pozantı- Karsantı ophiolite but some data from the Islahiye chromites areas. The plot for the Pozantı-Karsantı shows that plot outside of the Troodos due to the high most of the data lie in two main fields (Cr# between Cr/Fe ratio. 77-81 and 72-75). The compositional variations between single pods are mainly in Mg# rather than the degree of partial melting, the hydrous nature of Cr#, which can be explained by increases of ƒO the SSZ magma and magma mixing changes in P 2 and temperature, resulting in an increase of Mg# in and their affect on the partial pressures. The chromite. presence of subduction-derived water (hydrous In the plots of Mg# vs Fe+3#, the Fe3+# nature) in the melt could expand the olivine and indicates very limited variation and data are placed spinel phase volume and so to extensive within the podiform range. The data from the of olivine and chromite during the Karsantı and Pozantı areas remain in the podiform formation of the ophiolite. field and areas do not show any distinct chemical trend. The chromite mineral composition of the References stratiform deposits of Kızilyüksek shows the same Ballhaus C., 1998, Origin of podiform chromite pattern as podiform deposits. deposits by magma mingling. Earth Planet. The Pozantı and Karsantı chromite Sci. Lett., v.156, p. 185-193. Engin, T., Özkocak, O and Artan, U., 1986. analyses have low TiO2 contents (0.21 wt.%), which is characteristic for podiform chromite. General geological setting and character of Chromites from the study areas are clustered chromite deposits in Turkey, Petrascheck, mainly within the Troodos compositional field. W., Karamata, S., Kravchenko, G. G., Johan, Z., Economou, M., Engin., eds., T. Chromite Mineralisation and Relation of the Fac. Min. and Geol., Belgrade, Tectonic Setting of the Ophiolites Yugoslavia. p. 199-228. IGCP Project Pearce at al., (1984) analyzed the tectonic No. 197. settling of Tethyan ophiolites based on the Parlak, O., Höck, V. & Delaloye, M., 2000, Supra- geochemical data from the ophiolites and subduction zone origin of the Pozanti- concluded that Eastern Mediterranean and Middle Karsanti ophiolite (southern Turkey) East ophiolites are rich in ionic lithophile elements deduced from whole and mineral as a direct result of a different tectonic setting chemistry of the gabbroic cumulates. which was named as a Supra-Subduction Zone Bozkurt, E., Winchester, J.A. & Piper, J., (SSZ). They concluded that these ophiolites are a eds., Geological Society of London result of immature island arc magmatism. SSZ SpecialPublication, in: and ophiolite is characterized by depleted mantle magmatism in Turkey and its sequence. Therefore, the chemical compositions of surroundings. P. 219-234. chromite display variable degrees of the partial Pearce, J.A., Lippard, S.J. and Roberts, S., 1984. melting of host (Zhou and Robinson, Characteristics and Tectonic Significance 1997). Magma mixing plays important role of of Supra-Subduction Zone Ophiolites, forming podiform chromite (Ballhaus, 1998). “Marginal Basin Geology”, Kokelaar, B.P. Pearce et al. (1984) demonstrated that the and Howells., eds., M.F., Blackwell ophiolites in the Troodos massif, Hatay and Oman Scientific Pubs., p 77-94. are SSZ type, and Parlak (1999) reported that the Zhou, M.F. and Robinson, P.T., 1997, Origin and ophiolites in Mersin and Pozantı-Karsantı areas are tectonic environment of podiform also SSZ origin. chromite deposits: , v. During the formation of chromites, the 92, p. 259-262. following factors are involved in SSZ ophiolites: