STUDYING THE GENESIS OF IGNEOUS ROCKS IN ZARIN-KAMAR REGION (SHAHROOD, NORTHEASTERN IRAN) BY RARE EARTH ELEMENTS

Zarin-Kamar region is located north east of Shahrood (36o37’-36o42’N, 55007’-55012’E). Plutonic rocks in this area belongs to syenite group and their texture is intergranular hypidiomorphic. Volcanic rocks in the area have porphyritic, amygdale intersertal texture. which quartz is also seen among their cavities and porosities. Total concentration of REEs (ΣREE) in the study igneous rocks varies between 450 and 683 ppm. Diagram of Eu/Eu* versus Sr and Eu/Eu* versus Ba show negative anomalies of Eu. This phenomenon as well as Ba and Sr trends show that plagioclase removal has happened during the magma evolution. These rocks have rock has originated from an enriched mantle source. The rate of Dy/Yb in the igneous rocks of the region varies between 1.32 and 2.62. it shows that it stemmed from a garnet lherzolitic source. The rate of (Tb /Yb )N was between 0.97 to 2.25 showing a garnet source. Also other related figures showed that the samples belonged to OIB (Oceanic Island Basalt). The rate of La/Ta was between 6.6 to 14.01. It also showed that they had a source from asthenosphere. The rate of La/Nb was 0.5 to 0.91. It also shows a less crustal contamination among these samples.

[1]  M. Foudazi,et al.  Magmatic interactions as recorded in plagioclase phenocrysts of quaternary volcanics in SE Bam (SE Iran) , 2019 .

[2]  F. Ghadimi,et al.  Comparison of original and weighted singularity index in separation of Pb- Zn mineralized zone in the Haft Savaran district, central Iran , 2019 .

[3]  A. Bayramov,et al.  Mineral composition and paragenesis of altered and mineralized zones in the Gadir low sulfidation epithermal deposit (Lesser Caucasus, Azerbaijan) , 2019 .

[4]  M. Emami,et al.  Chemistry of Minerals and Geothermobarometry of Volcanic Rocks in the Region Located in Southeast of Bam, Kerman Province , 2017 .

[5]  K. Koga,et al.  Simple mixing as the major control of the evolution of volcanic suites in the Ecuadorian Andes , 2009 .

[6]  M. C. Göncüoğlu,et al.  Geochemistry of mafic rocks of the Karakaya complex, Turkey: evidence for plume-involvement in the Palaeotethyan extensional regime during the Middle and Late Triassic , 2009 .

[7]  M. Salavati.  Petrology, Geochemistry and Mineral Chemistry of Extrusive Alkalic Rocks of the Southern Caspian Sea Ophiolite, Northern Alborz, Iran: Evidence of Alkaline Magmatism in Southern Eurasia , 2008 .

[8]  J. Pearce.  Geochemical fingerprinting of oceanic basalts with applications to ophiolite classification and the search for Archean oceanic crust , 2008 .

[9]  Z. Abu-Hamatteh.  Geochemistry and petrogenesis of mafic magmatic rocks of the Jharol Belt, India: geodynamic implication , 2005 .

[10]  F. Nader,et al.  Characterization of the Lebanese Jurassic–Cretaceous carbonate stratigraphic sequence: a geochemical approach , 2002 .

[11]  D. Peate,et al.  Tectonic Implications of the Composition of Volcanic Arc Magmas , 1995 .

[12]  E. Middlemost.  Naming materials in the magma/igneous rock system , 1994 .

[13]  T. Bradshaw,et al.  Polygenetic Quaternary volcanism at Crater Flat, Nevada , 1994 .

[14]  W. Leeman,et al.  Basic magmatism associated with Late Cenozoic extension in the western United States: Compositional variations in space and time , 1991 .

[15]  G. Eby.  The A-type granitoids: A review of their occurrence and chemical characteristics and speculations on their petrogenesis , 1990 .

[16]  A. Hall.  Igneous Petrogenesis: A Global Tectonic Approach , 1989, Mineralogical Magazine.

[17]  M. A. Morrison,et al.  Asthenospheric and lower-lithospheric mantle contributions to continental extensional magmatism: An example from the British Tertiary Province , 1988 .

[18]  M. A. Morrison,et al.  Compositionally-Diverse Miocene—Recent Rift-Related Magmatism in Northwest Colorado: Partial Melting, and Mixing of Mafic Magmas from 3 Different Asthenospheric and Lithospheric Mantle Sources , 1988 .

[19]  S. Jackson,et al.  Geochemistry of bimodal basalt-subalkaline/peralkaline rhyolite provinces within the Southern British Caledonides , 1986, Journal of the Geological Society.

[20]  W. Boynton.  Geochemistry of the rare earth elements : meteorite studies , 1984 .

[21]  D. Wood,et al.  Elemental and Sr isotope variations in basic lavas from Iceland and the surrounding ocean floor , 1979 .