An approach to geochemical characterization of productive versus barren granitoids in terms of iron in Central Turkey


KUŞCU I., Gencalioglu-Kuscu G., Sarac C. , Meinert L.

JOURNAL OF ASIAN EARTH SCIENCES, cilt.24, ss.311-325, 2004 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 24 Konu: 3
  • Basım Tarihi: 2004
  • Doi Numarası: 10.1016/j.jseaes.2003.12.007
  • Dergi Adı: JOURNAL OF ASIAN EARTH SCIENCES
  • Sayfa Sayıları: ss.311-325

Özet

The granitoids associated with and without skarn type mineralizations in central Anatolia are. termed as productive and barren respectively. The Study of the relationships between plutonic rocks in the Central Anatolian Crystalline Complex in central Turkey suggests,:is a direct genetic connection between the composition of plutons, and their associated ore deposits. In order to discriminate between productive and barren granitoids, two Fe-skarn granitoids (Celebi and Karamadazi). and a series of barren plutons within central Anatolia were examined. The Karamadazi and Celebi granitoids are geochemically different from other barren plutons in Central Anatolia. The parameters governing the productivity of these granitoids were determined by principal component analysis (factor analysis) method. Based on this method, the factors controlling the geochemical characteristics of the Celebi granitoids are (Al2O3 divided by MgO divided by Fe2O3 divided by P2O5 divided by TiO2 divided by CaO)/(SiO2), (K2O + Rb)/(Na2O) and Rb/Sr ratios, and for the Karamadazi granitoid the (Fe2O3 divided by MnO divided by MgO divided by P2O5 divided byY)/(SiO2 divided by Rb) (FMMY/S) and (Na2O)/(K2O) ratios. These two granitoids are clearly distinguished front the barren Central Anatolian Granitoids (CAG) on Harker diagrams based oil these controlling factors (parameters). Barren CAG plutons are different front the productive Celebi granitoids in their higher silica content and generally higher total alkali values. This study suggests that iron-producing granitoids are less differentiated and receive little contribution from continental crust compared to the barren granitoids. Higher apatite and zircon abundance in the Celebi granitoids suggest that the Celebi granitoids have more I-type characteristics compared to barren plutons of CAG. The Karamadazi granitoid is the most striking example for the granitoids in CAG, having a higher contribution front the continental crust ass evidenced by higher Rb. Ba. Th, the highest mean Sc, V, and mean Zr, Y, Ni contents. Based on the factor analysis, it is proposed that the Karamadazi granitoid displays geochemical characteristics similar to the Terlermez and Agacoren granitoids of CAG. The factor analyses indicated that the first two factors are about the same for both the Fe-producing Celebi and Karamadazi granitoids. Therefore. this similarity has let to a conclusion that the productivity or non-productivity of the granitoids in Central Anatolia can be tested by examining and comparing the distribution of granitoids in diagrams designed according to the factors defined in this study. (C) 2004 Elsevier Ltd. All rights reserved.