Document Type : Original Research Paper

Authors

1 Geological Department, Tarbiat Modarres University, Tehran, Iran

2 Research Institute for Earth Science, Geological Survey of Iran, Tehran, Iran

Abstract

Kamtal intrusion is located in East Azarbaijan province, NW of Iran, near the Armenia border. The Kamtal intrusion consist of an acidic part with monzogranitic composition and an intermediate- basic part which compositionally composed of monzonite, monzodiorite, quartz  monzonite, quartz monzodiorite and gabbro. Gabbroic rocks exist in the form of small lenses in the southeast of Kamtal intrusion within the intermediate part. The intermediate- basic part has been intruded by the acidic part. Both acidic and intermediate parts are high-K calc-alkaline, metaluminous in character and classified as I-type granitoids; while, the gabbros have tholeiitic nature.
     Both acidic and intermediate rocks show a LREE rich pattern and high LREE/HREE ratio. These two parts have differences in MREE enrichment. From similarity in REE patterns of acidic and intermediate rocks a genetic relation can be discerned. Negative anomalies of Nb and Ti can be seen in all rock phases of the Kamtal intrusion, representing the subduction zone setting. Comparison of trace element variations with those of granitoid rocks of different tectonic settings show similarities between Kamtal intrusion and Andean volcanic arc granitoids. Furthermore, Kamtal intrusion can be classified as VAG based upon tectonic setting discrimination diagrams. It is concluded that, Kamtal intrusion probably is the result of Neotethys oceanic crust subduction beneath the Caucasus continental plate.   

Keywords

References
Barbarin, B., 1999- A review of the relationship between granitoid types, their origins and their geodynamic environments, Lithos, V. 46, P. 605-626.
Batcelor, R. A. and Bowden, P., 1985- Petrogenetic interpretation of granitoid rocks series using multicationic parameters, Chemical geology, V. 48, P. 43-55.
Chappell, B. W. and White, A. J. R., 2001- Two contrasting granite types: 25 years later, Australian Journal of Earth Sciences, V. 48, P. 489-499.
Collins, W. J., Beams, S. D., White, A. J. R. and Chappell, B. W., 1980- Nature and origin of A- type granites with particular reference to south eastern Australia, Contrib. Mineral. Petrol., V. 80, P. 189-200.
Dercourt, J., Zonenshain, L. P., Ricou, L. -E., Kazmin, V. G., Le Pichon,  X., Knipper, A. L., Grandjacquet, C., Sbortshikov, I.M., Geyssant, J., Lepvrie,  C., Pechersky, D. H., Boulin, J., Sibuet, J. -C., Savostin, L. A., Sorokhtin, O., Westphalh, M., Bazhenov, M. L., Lauerh J. P., and Biju-Duval, B., 1986- Geological Evolution of the Tethys Belt from the Atlantic to the Pamirs since the Lias. Tectonophysics, V. 123, P. 241-315.
Didier, J., Duthou, J. L. and Lameyre, J., 1982- Mantle and Crustal granites: Genetic classification of Orogenic granites and nature of their enclaves, J. Volca. Geoth. Res., V. 14, P. 125-132.
Harris, N. B. W., Pearce, J. A. and Tindle, A. G., 1986- Geochemical characteristics of collision zone magmatism. In: Coward, M. P. and Ries, A. C. (eds.), Collision Tectonics, Geological Society London, Special Publication, V.19, P. 67-81.
Irvine, T. N. and Baragar, W. R. A., 1971- A guide to the chemical classification of the common volcanic rocks, Canadian journal of earth science, V. 8, P. 523-276.
LeMaitre, R. W., Bateman, P., Dudek, A., Keller, J., Lemeyre, LeBas, M. J., Sabine, P. A., Schmid, R., Sorensen, H., Streckeisene, A., Wooley, A. R. and Zanettin, B., 1989- A classification igneous rocks and glassory of terms, Blackwell, Oxford, 193p.
Maniar, P. D. and Piccoli, P. M., 1984- Tectonic discrimination of granitoids, Geological society of America bulletin, V. 101, P. 635-643.
Pearce, J. A., Harris, N .B. W. and Tindle, A. G., 1984- Trace element discrimination diagrams for the tectonic interpretation of granitic rocks, Journal of Petrology, V. 25, P. 956-983.
Pearce, J. A., 1996- Sources and setting of granitic rocks, Episodes, V. 19, N. 4, P. 120-125.
Philip, H., Cisternas, A., Gvishiani A., and Gorshkov, A., 1989- The Caucasus: an actual example of the initial stages of continental collision, Tectonophysics, V. 161, P. 1-21.
Pitcher, W. S., 1983- Granite types and tectonic environment. In: Hsu, K. (ed.), MountainBuilding Processes, Academic Press, London, P. 19-40.
Rickwood, P. C., 1989- Boundary lines within petrologic diagrams which use oxide of major and minor elements, Lithos, V. 22, P. 247-264.
Sajona, F. G., Maury, R. C., Bellon, H., Cotton, J. And Defant, M., 1996- High field strength elements of Pliocene- Pleistocene island arc basalts ZamboangaPeninsula, Western Mindanao (Philippines), Journal of Petrology, V. 37, P. 693-726.
Whalen, J. B., Currie, K. L. and Chappell, B. W., 1987- A-type granites: geochemical characteristics, discrimination and Petrogenesis, Contrib. Mineral. Petrol., V. 95, P. 407-419.
White, A. J. R. and Chappell, B. W., 2004- Petrographic discrimination of low and high temperature I-type granites, Resource geology, V. 54, N. 3, P. 215-226.
Wilson, M., 1989- Igneous petrology, Unwin Hyman, London, 466 p.
Zonen Shain, L. P. and Le Pichon, X., 1986- Deep basins of the Black sea and the Caspian Sea as remnants of Mesozoic back- arc basins, Tectonophysics, V. 123, P. 181-211.