فعالیت همزمان ماگماهای آنورتوزیتی و گرانیتی نوع - S در باتولیت چاه دزدان، نیریز، ایران: شواهدی از سن سنجی زیر کن به روش SHRIMP و مونازیت به روش CHIME

U-Th zircon SHRIMP and U-Th-total Pb monazite CHIME ages of 6 typical samples were established among different rock types outcropped into the Chah-Dozdan batholith from Iran. The zircon population displays simple internal structures in samples of the Chah-Dozdan batholith. The zircon crystals have well-preserved magmatic characteristics. In all population, the rims display younger ages than the cores, presumably due to late-magmatic crystallization. Zircon grains of anorthosites exhibit magmatic ages c. 170.5 ± 1.9 Ma and 173.0 ± 1.6 Ma. Zircon SHRIMP U-Th ages of metapelitic xenoliths and S-type granites from Chah-Dozdan pluton are c. 167.0 ± 3.1 Ma and 164.3 ± 8.1 Ma, respectively. Monazite grains are generally concordant in electron microprobe analysis and give Th-U-total Pb isochron ages in agreement with zircon SHRIMP U-Pb ages. The sub-grain analyses of monazite are plotted on the coordinates of PbO and ThO* (ThO plus the equivalent of UO2). Data points fit linearly and clearly defined an isochron which passes thorough the origin. Small patches of the S-type granites and metapelitic xenoliths yield chemical Th-U-total Pb isochron ages of monazite c. 171 ± 16 Ma and 165 ± 42 Ma, respectively. Emplacement of anorthositic magma into metapelites from the Qori metamorphic complex at mid-crustal depth resulted into fundamental contamination of this magma via breaking down of blocks of host rock into it, in the form of xenoliths within intruded magma, and s-type granite via partial melting of metapelitic xenoliths.