sr-nd isotopic characteristic, u-pb zircon geochronology, and petrogenesis of najmabad granodiorite batholith, eastern iran
نویسندگان
چکیده
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.
منابع مشابه
petrogenesis of granitoids, u-pb zircon geochronology, sr-nd petrogenesis of granitoids, u-pb zircon geochronology, sr-nd isotopic characteristics, and important occurrence of tertiary mineralization within the lut block, eastern iran
tertiary intrusive granitoids within the lut block in the khorasan razavi and south khorasan provinces are mainly sub-volcanic with porphyry texture and their composition varies from granite to diorite but monzonite is dominant. with the exception of hired, these are classified as belonging to the magnetite-series of i-type granitoids. chemically, these rocks are meta-aluminous. those with mine...
متن کاملU–Pb zircon geochronology, petrochemical and Sr–Nd isotopic characteristic of Late Neoproterozoic granitoid of the Bornaward Complex (Bardaskan-NE Iran)
http://dx.doi.org/10.1016/j.jseaes.2015.05.019 1367-9120/ 2015 Elsevier Ltd. All rights reserved. ⇑ Corresponding author. Tel.: +98 5138218146, mobile: +98 9155011318; fax: +98 5138212402. E-mail addresses: [email protected] (R.M. Bagherzadeh), [email protected] (M.H. Karimpour), [email protected] (G.L. Farmer), [email protected] (C.R. Stern), [email protected] (J.F. Santos)...
متن کاملAdakite magmatism within the Sabzevar ophiolite zone, NE Iran: U-Pb geochronology and Sr-Nd isotopic evidences
Numerous post-ophiolite intrusions exposed into the late Cretaceous–Paleocene Sabzevar ophiolite belt, northeast Iran. The intrusions consist of calc-alkaline intermediate to felsic rocks with metaluminous to peraluminous in nature and adakitic affinities. Based on U-Th-Pb dating on separated zircons by SHRIMP Ⅱ, the emplacement age of these rocks into the ophiolite zone is constrained to ~45 M...
متن کاملu-pb zircon geochronology, sr-nd isotope geochemistry, and petrogenesis of oxidant granitoids at keybarkuh, southwest of khaf
keybarkuh area is located 70 km southwest of khaf, khorasan razavi province. the study area is situated in northeastern lut block. the rock units in the area are paleozoic metamorphic rocks and cretaceous to tertiary subvolcanic intrusions intruded as dike, stock and batholith; their composition varies from granite to diorite. based on magnetic susceptibility, the intrusive rocks are divided in...
متن کاملgeology, mineralization, rb-sr & sm-nd geochemistry, and u–pb zircon geochronology of kalateh ahani cretaceous intrusive rocks, southeast gonabad
kalateh ahani is located 27 km southeast of gonabad within the khorasan razavi province. the area is part of lut block. sub-volcanic monzonitic rocks intruded regional metamorphosed shemshak formation (jurassic age). magnetic susceptibility of less altered monzonitic rocks is 0.6%., as, pb and zn > 1%, au up to 150 ppb and sn = 133 ppm. the sn content of vein in the northern part of kalateh aha...
متن کاملOxygen Isotopic Composition and U-Pb Discordance in Zircon
We have investigated U-Pb discordance and oxygen isotopic composition of zircon using high– spatial resolution !O measurement by ion microprobe. !O in both concordant and discordant zircon grains provides an indication of the relationship between fluid interaction and discordance. Our results suggest that three characteristics of zircon are interrelated: (1) U-Pb systematics and concomitant age...
متن کاملمنابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
زمین شناسی اقتصادیجلد ۳، شماره ۲، صفحات ۱۲۷-۰
میزبانی شده توسط پلتفرم ابری doprax.com
copyright © 2015-2023