Document Type : Original Research Paper

Authors

1 School of Geology, University College of Science, University of Tehran, Tehran, Iran

2 Faculty of Sciences, Shahroud University of Technology, Shahroud, Iran

Abstract

     The intrusive bodies of Central Alborz constiute speciale distribution. And they are located near major faults, and also they are accompnied by pyroclastic rocks of the Karaj Formation.Moreover they  display lithological diversity and they occur as sill, lopolith, stock and plug.
These intrusive bodies blong to post upper Eocene and they are related to the Pyrenean- equivalent orogenic phase.
Rregarding the geochemical results obtained by other researchers, as well as determining the nomenclature, definiton of granitoid and gabbroic bodies the composition of the above mentioned masses, fall within the calc - alkaline to alcaline range.
However, most specimens are plotted  in the field of  type I granitoids.From the tectonic viewpoint, all of  the intrusive bodies are Considered as syntectonic. Moreover, they are often of continental subduction Zone(CAG)origin , while other may be long to continental collision type(CCG), and a few are located to the island arcs(IAG).

Keywords

References
 Allenbach, P., 1966- Geologie und petrographie des damavand und seiner umgeburg(Zentral Elburz), Iran, mitteilung Nr.63, geologisches institut, ETH – zurich, 114 P.
Annells, R. N., Arthurtoh, R. S., Bazley, R A. & Davies, R. G., 1975- Explanatory text of the Qazvin and rasht quadrangles map. Geological survey of Iran, E3 and E4, 94P.
Assereto, R., 1966 b- Geological map of upper Djadjrud and lar valleys(central Eiburz, Iran), scale 1:50,000 with explanatory notes. Ist. Geol. Univ. milano, ser. G. Publ. 232.
Berberian, M., 1976 b- Contribution to the seismotectonics of Iran(Part II). Geo, surv, of Iran, Rep. No. 39,518 P, 5 maps, 259 figures.
Cas, R. A. F. & Wright, J. V, 1987- Volcnic sucessins, modern and Ancient, Allen and unwin hyman, London. 528 PP.
Chappell, B. W. & white, A.J. R.,1992- I- and S-type granites in lachland fold belt: Trans R., SOC. Edinb earth sci. 83, P. 1-26.
De Bon, F. & Le Fort, P., 1983- A chemical – mineralogical classification of common plutonic rocks and associations, R. Soc. Edinb., Trans., 73 P. 135.
Dedual, E., 1967- Zur geologie des mittleren und unteren karaj Tales, Zentral Elburz(Iran). mitt. Geol. Inst. E. T. H. U. univ. zurich, n. s., n. 75, 125 P.
Dellenbach, J., 1964 -Contribution a letude geologique de la region situee a lest de teheran(Iran), FAC. Sci., Univ. strasbourg(France), 117 P.
Gansser, A. & Huber, H., 1962- Geological observations in central Elburz Iran. Schweizerische mineralogische und petographische mitt, 42(4), PP. 583-630.
Hyndman, D. W., 1985- Petrology of Igneous and metamorphic rocks, MC – Graw – Hill, Newyork, 786 PP.
Irvin, T. N. & Baragar, W. R. A., 1971- A guide to the chemical classification of the common volcanic rocks, canadian. Jour. Eart. Sci., No. 8, P. 523-548.
Jung, D., Kursten, M. & Tarkian, M.,1976- Post mesozoic volcanism in Iran and its relation to the subduction of the afro Arabian under the eurasian plate. In Afar between continental and oceanic rifting(V. II).Eted by pilger and Rosler. E. Sehw. Verl. Hamdlung, stuttgart, PP. 175-181.
Maniar, P. D. & Piccoli, P. M., 1989- Tectonic discrimination of granitoids, Geo. Soc. Am. Bull. , V. 101. P. 635-643.
Meyer, S. P., 1967- Die Geologie des Gebietes velian – Kechire(zenteral – Elburz, Iran) These Zurich. Mitt. Geol. Inst,. N. F. 79, 127 P.
Middlemost, E. A. K., 1987-Magas and Magatic Rocks An Introduction to Igneous petrology. Longman group U. K. 266 P.
Midelemost, E. A. K., 1985- Naming materials in The magma/igneous rock System Longman Groun u. k., pp.73-86.
Rollinson. R., 1993- Using geochemical Data. Evoluation, presentation, Interpretation, Longman scientific and Techncal, U. K. 352PP.
Stalder, P., 1971- Magmutisems tertiarie. Et subrecent entre Taleghan et Alamout, Elbourz central(Iran) Bull. Suiss de Min. petr, vol, 51/1, 139PP.
Stocklinn, J., 1974, a-Northern Iran: Alborz mountains. Meszoic – senozoic orogenic Belt, data for orogenic studies, Geol. Soc, london, Sp. Pub4, P. 213-234(Collec. Ed. A. M.Spenncer, scottish Academic press).
White, A.  J.  R. & chappell, B. W., 1977- Ultrametamorphism and granitoid genesis: Tectonophysics, 43, P. 7-22.
Whitney, J. A. ,1988- Magmatic conditions and development of chemical zonation in the C arpenter Ridga Tuff, central san Volcanic field, Colorado: American Jour of Science, Wones Memorial, v. 231, P.
Wilson, M., 1989- Igneous petrogenesis a global tectonic approach. Unwin Hyman Ltd, London 466P.
Wyllie, P.  J., 1984- Sources of granitoid magmas at convergent plate boundaries, Planetary interiors No. 35, 12-18 P.