New Findings in Applied Geology

New Findings in Applied Geology

Geochemistry of mafic igneous rocks of Baghcheghaz region (northeast of Hamedan province): with emphasis on origin and tectonic environment

Authors
S. Asadbeygi 1
H. Shahbazi 2
1 Ph. D. student. Dept., of Geology, Faculty of Science, Bu Ali Sina University, Hamedan, Iran
2 Assoc. Prof., Dept., of Geology, Faculty of Science, Bu Ali Sina University, Hamedan, Iran
10.22084/nfag.2024.29351.1614
Abstract
The Baghcheghaz intrusive mass is exposed in Hamadan province and in the northeast of Famenin city in the Sanandaj zone of Sirjan. Based on petrographic and geochemical studies, the type of rock that forms the mass is gabbro. The results of geochemical analysis show that these rocks are related to calcalkaline and tholeiite magmatic series. The trends formed in the Harker diagrams and their geochemical continuity, the patterns of the spider diagrams and the parallelism of the trends of these diagrams and the existence of enrichment in K and Pb elements and depletion in Nb confirm the common origin of the samples and indicate the involvement of magma with the continental crust. The nature and chemical composition of rocks in the region have undergone magmatic processes such as fractional crystallization, and contamination.The pattern of changes of normalized rare earth elements compared to chondrite and primary mantle show that the values ​​of rare earth elements LREE are higher than heavy earth elements HREE. The graphs related to the rare elements show that the magma forming the igneous rocks of the Baghcheghaz intrusive mass originates from the mantle with the composition of spinel lherzolite and with a low to medium partial melting degree (5% to about 30%) and in a subduction environment and volcanic arcs are formed on the active continental margin.
Keywords
Gabbro
Geochemistry
Petrology
Sanandaj-Sirjan zone
Abdallah, J. A. Said, A. Visona, D (1997) New geochemical and petrographic data on the gabbro-syenite suite between Hargeysa and Berbera-Shiikh(Northern Somalia). Jour of African earth scinces, 23 (3): 363-373.
Bowden, P., Batchelor, R. A., Chappell, B. W., Didier, J., Lameyre, J (1984) petrological geochemical and source criteria for the classification of granitic rocks: a discussion. Phys. Earth Planet. In, 35: 1-11.
Boynton, W. V (1984) Cosmochemistry of the rare elements: meteorite studies in: Henderson, p. (ed) Rare Earth Element Geochemistry. Elsevies, Amsterdam, 63: 114.
Cox, K. G. Bell, J. D. Pankhurst, R. J (1979) the Interpretation of Igneous Rocks. Allen and Unwin, London, pp. 450.
Furman, T (2007) Geochemistry of East African Rift basalts: An overview. Journal of African Earth Sciences, 48: 147-160.
Shahbazi, H., Siebel, W., Pourmoafee, M., Ghorbani, M., Sepahi, A. A., Shang, C. K., and Vousoughi Abedini, M (2010) Geochemistry and U–Pb zircon geochronology of the Alvand plutonic complex in Sanandaj–Sirjan Zone (Iran): New evidence for Jurassic magmatism. Journal of Asian Earth Sciences, 39(6): 668–683.
Harker, A (1909) the natural history of igneous rocks. Methuen, London.
Hofmann, A. M (1997) Mantle geochemistry: the message from ocean volcanism. Nature, 385: 219-229.
Hofmann, A. M., Jochum, K. P., Seufert, M., and White, W. M (1986) Nd and Pb in oceanic basalts: new constraints on mantle evolution. Earth and Planetary Science, 79: 33-45.
Irvine, T. N., Baragar, W. R. A (1971) Guide to the chemical classification on the common volcanic rocks. Can. J. Earth Science, 8: 484-523.
Machado, A., Lima, E. F., Chemale, J. F., Morta, D., Oteiza, O., Almeida, D. P. M., Figueiredo, A. M. G., Alexandre, F. M., Urrutia, J. L (2005) Geochemistry constraints of MesoCzoic-CenoCzoic calk-alkaline magmatism in the  South Shetland arc, Antarctica, Earth Science. South American, 18: 407-425.
Middlemost, E. A. K (1985) Magmas and magmatic rocks, an introduction to igneous petrology, Longman: London.
Mohajjel, M (1997) Structure and tectonic evolution of PaleoCzoic-MesoCzoic rocks, Sanandaj-Sirjan Czone, western Iran.-Ph. D. Thesis University of Wollongong, Wollongong, Australia.
 
Mohammadi Tabar, S. J (2019) Petrology of leucocratic Intrusive Igneous rocks in the Baghcheh Ghaz area North-East of Famenin; (North-East Hamedan Province). BU-Ali Sina University, Faculty of Science, Department of Geology. Thesis of M. Sc.
Nagudi, N. O., Koberl, C. H., Kurat, G (2003) Petrography and geochmistry of the Singo granite, Uganda and implications for its origin. Journal of African earth sciences, 35: 51-59.
Nelson, S. A (2004) Magmatic Differentiation, Chemical variations in rock suites. Tulan University New Orleans, Louisiana, United States.
Pearce, J. A., Gale, G. H (1977) Identification of ore-deposition environment from trace element geochemistry of associated igneous host rocks, 7: 14-24.
Pearce, J. A (1983) Role of the sub-continental lithosphere in magma genesis at active continental margin. In: Hawkesworth, C. J. and Norry, M. J. (Eds): Cotinental basalts and mantle xenoliths. Shiva, Nantwich, 230-249.
Pearce, J. A. Cann, J. R (1973) Tectonic setting of basic volcanic rocks determined using trace element analysis. Earth Planet. Science Letters, 19: 290-300.
Pearce, J. A. Cann, J. R (1971) Ophiolite origin investigated by discriminate analysis using Ti, Zr and Y. Earth Planet. Science Letters, 12: 339-349.
Pearce, J. A (1996) Sources and settings of granitic rocks. Episodes, 19: 120-125.
Pearce, J. A., Kempton, P. D., Nowell, G. M., and Noble, S. R (1999) Hf-Nd element and isotope perspective on the nature and provenance of mantle and subduction components in western Pacific arc-basin systems.Journalof Petrology, 40: 1579-1611.
Pinto-Linares, P. J., Levresse, G., Tritlla, J., Valencia, V. A., Torres –Aguilera, J. M., Gozalez, M., Estrada, D (2008) Transitional adakite-like to calkalkalinmagmas in a continental extensional setting at La Paz Au-Cu skarn deposits, Mesa Central, Mexico: metallogenic implications, Revista Mexicana de Ciencias Geological, 25: 39-58.
Rollinson, H (1993) Using geochemical data: evolution, presentation, interpretation. Longman Scientific Technical, London.
Rollinson, H (1997) Using geochemical datas, evaluation, presentation, Johen Wiley and sons, 346pp.
Rudnick, R. L., and Fountain, D. M (1995) Nature and composition of the continental crust: a lower crustal perspective. Reviews of Geophysics, 33: 267-309.
Sun, S. S., Mc Donough, W. F (1989) Chemical and isotopic systematic of ocean basalts: implications for mantle composition and processes. In: Saunders, A. D. and Norry, M. J. (Eds.): Magmatism in ocean basins. Geological Society of London, Special Publication, 313-345.
Sun, S. S., McDonough, W. F (1982) Chemical and isotopic systematics of ocean basalts: implications for mantle composition and processes. In: Saunders, A. D. Norry, M. J. (Eds.), Magmatism in the ocean basins. Geol. Soc. London Spec. Pulb, 42: 313-345.
Taylor, S. R., McLennan, S. M (1985) the continental crust: its composition and evolution. Blackwell, Oxford, England.
New Findings in Applied Geology
Volume 19, Issue 38 - Serial Number 38
December 2025
Pages 117-131

  • Receive Date 15 May 2024
  • Revise Date 17 September 2024
  • Accept Date 22 September 2024