Sr-Nd isotopic characteristic, U-Pb zircon geochronology, and petrogenesis of Najmabad Granodiorite batholith, Eastern Iran

زمین شناسی اقتصادی

Article 3, Volume 3, Issue 2 - Serial Number 5, February 2012, Pages 127-145   

Document Type: Research Article

DOI: 10.22067/econg.v3i2.11436

Authors

Mehrab Moradi Noghondar^{* 1}; Mohammad Hassan Karimpour¹; G. Lang Farmer²; Charles R. Stern²

¹Ferdowsi University of Mashhad

²Colorado

Abstract

The study area is located south of Ghonabad in Eastern Iran. This area is situated between two major faults, Darouneh to the north and Dashtbyaz to the south. The movements of these faults cased major dislocation of this block. Najmabad granodiorite to granite batholith is elongated trending east-west 2×8 Km2. Mineralization is associated with granite and monzonite. Alteration zones are: propylitic, sericitic, argillic and silicification. Chemically, granite-granodiorite is met-aluminous,, spider diagram normalized to lower continental crust show enrichment of LILE such as Rb, Cs, K and LREE (La, Ce) , depletion of Ti, Sr, Ta, Nb, Ba, Cs. Based on low values of magnetic susceptibility [(5 to 11) × 10-5 SI], therefore it is classified as belonging to the ilmenite-series (reduced type).The result of U-Pb zircon age dating of granodiorite is 161.85 Ma (Middle Jurassic, Callovian time). Based on Initial εNd isotope values for granodiorite is -6.51, initial 87Sr/86Sr and 143Nd/144Nd ratios for granodiorite is (0.70913 and 0.512095), the magma for granite and granodiorite originated from the continental crust. During Middle Jurassic (Callovian) due to continental collision, Upper Triassic to Lower Jurassic rocks is regionally metamorphosed. During the continental collision, Middle Jurassic (164-162Ma) reduced type granitoid magma (Ilmenite series, continental crust melting) formed and intruded these regional metamorphosed rock in Najmabad, Shah Kuh and Sorkh Kuh area.

Keywords

Najmabad; Granite; Zircon; continental collision; magma

References

[1] Esmaeily D., "Petrology and geochronology of Shah- Kuh granite with special references to tin mineralization", unpublished Ph.D thesis, TarbiatModares University (2001) 296 p.

[2] Camp V., Griffis R., "Character, genesis and tectonic setting of igneous rocks in the Sistan suture zone, eastern Iran", Lithous, Issn 0024-4937 v 15 (1982) 221-239.

[3] Tirrul R., Bell I. R., Griffis R. J., Camp V. E., "The Sistan suture zone of eastern iran", Geolc. Soc. Am. Bull 94 (1983) 134-156.

[4] Jung D., Keller J., Khorasani R., Marcks C., Baumann A., Horn P., "Petrology of the Tertiary magmatic activity the northern Lut area, East of Iran", Ministry of mines and metals, GSI, geodynamic project (geotraverse) in Iran No 51 (1983) 285-336.

[5] Tarkian M., Lotfi M., Baumann A., "Tectonic, magmatism and the formation of mineral deposits in the central Lut, east Iran", Ministry of mines and metals, GSI, geodynamic project (geotraverse) in Iran No 51 (1983) 357-383.

[6] آقانباتی ع.، "زمین شناسی ایران"، سازمان زمین شناسی و اکتشافات معدنی کشور، (1383) ٦٠٦ص.

[7] قائمی ف.، " نقشه زمین شناسی 1:100000 گناباد"، سازمان زمین شناسی کشور، (1384).

[8] داوود زاده اشمیت.، "گزارش زمین شناسی شرق ایران، بلوک لوت"، (1983).

[9] Berberian M., Jackson J. A., Qorashi M., Khatib M. M., Priestley K., Talebian M., Ghafuri-Ashtiani M., "The 1997 may 10 Zirkuh (Qaenat) earthquake (Mw 7.2): faulting along the Sistan suture zone of eastern Iran", Geophys. J. Int (1999) 671-694.

[10] Rowan L. C., Hook S. J., Abrams M. J., Mars J. C., "Mapping hydrothermally altered rocks at Cuprite, Nevada, using the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), A new satellite imaging system",Economic Geology 98 no 5 p 1019-1027 (2003) DOI: 10.2113/98.5.1019.

[11] Yamaguchi Y., Rowan L. C., Tsu H., Kahle A. B., "Application of ASTER data to geological studies" Proceedings of the Eleventh thematic conference on geologic remote sensing; practical solutions for real world problems 11 (1996) I.77-I.86.

[12] Rowan L. C., Mars J. C., "Lithologic mapping in the Mountain Pass, California, area using Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data" Remote Sensing of Environment, v. 84, no. (3), p. 350–366, 2003. DOI: 10.1016/S0034-4257 (02) 00127-X.

[13] Hubbard B. E., Rowan L. C., Dusel-Bacon C., Eppinger R. G., "Geologic Mapping and Mineral Resource Assessment of the Healy and Talkeetna Mountains Quadrangles, Alaska Using Minimal Cloud- and Snow-Cover ASTER Data.USGS Open-File Report", 2007–1046.

[14] Middlemost E. A. K., "Magmas and Magmatic Rocks" London: Longman, Naming materials in the magma/igneous rock system, Earth-Sciences Reviews 37 (1985)215–224.

[15] Shand S. J., "Eruptive Rocks; Their Genesis, Composition, Classification, and their Relation to Ore Deposits", with a chapter on Meteorites (revised second edition): Hafner Publishing Co., New York (1943) 444 p.

[16] Taylor S. R., McLennan S. M., "The Continental Crust; Its composition and evolution; an examination of the geochemical record preserved in sedimentary rocks", Blackwell, Oxford (1985) 312.

[17] Sun S., McDonough W. F., "Chemical and Isotopic Systematics of oceanic basalts: implications for Mantle Composition and Processes", Spec. Publ. Vol. Geol. Soc. Lond. No 42 (1989) 313-345.

[18] Burnham C. W., Ohmoto H., "Late- stage processes of felsic magmatism, in Ishihara", S. and Takenouchi, S. Ceds., Granitic magmatism and related mineralization: Mining Geology, Spec. Issue No 8 (1980) 1-11.

[19] Ishihara S., "The magnetite-series and ilmenite-series granitic Rocks", Mining Geology 27 (1977) 293-305.

[20] Garrido C. J., Bodinier J. L., Burg J. P., Zeilinger G., Hussain S., Dawood H., Chaudhry M. N., Gervilla F., "Petrogenesis of mafic garnetgranulite in the lower crust of the KohistanPaleoarcComplex (Northern Pakistan): Implications forintra-crustal differentiation of island arcs andgeneration of continental crust", Journal of Petrology 47 (2009) 1873–1914.

[21] Campbell I. H., Ballard J. R., "U-Pb Zircon Geochronology of Granitic Rocks from the Chuquicamata-El Abra Porphyry Copper Belt of Northern Chile: Excimer Laser Ablation ICP-MS Analysis", Economic Geology, Bulletin of th society of economic geologists 101 NO 7 (2006) 1327-1344.

[22] Esmaeily D., Nedelec A., Valizadeh M. V., Moore F., Cotton J., "Petrology of the Jurassic Shah-Kuh granite (eastern Iran), with reference to tin mineralization", Journal of Asian Earth Sciences 25 (2005) 961-980.

[23] Jung D., Keller J., Khorasani R., Marcks Chr., Baumann A., Horn P., "Petrology of the Tertiary magmatic activity the northern Lut area, East of Iran" Ministry of mines and metals, GSI, geodynamic project (geotraverse) in Iran No 51 (1983) 285-336.