U-Pb zircon geochronology, geochemistry, and Sr-Nd-Pb-Hf isotopic composition of the Late Cretaceous monzogranite from the north of the Yidun Arc, Tibetan Plateau Eastern, SW China: petrogenesis and tectonic implication

Abstract

The Yidun Arc belt, a Triassic volcanic arc, was the result of Late Triassic large-scale subduction orogenic process of Paleo-Tethys and exposed the voluminous intermediate-acid intrusions during Mesozoic. In this paper, we mainly present petrography and petrology, major and trace element, Sr-Nd-Pb-Hf isotopic compositions, and zircon U-Pb ages for the monzogranites from the Queer Mountains area at the northern of Yidun Arc. The Queer Mountains monzogranites were emplaced at 93.6 ± 0.9 Ma (MSWD = 6.8, n = 34, 2σ), revealing that the monzogranites are the products of magmatism during the period of Late Cretaceous (BYanshanian^). The monzogranites have high SiO 2 , Al 2 O 3 , and K 2 O contents and enrichment in light rare earth elements (LREEs) and large-ion lithophile elements (LILEs) but depleted in high field strength elements contents (HFSEs), with relatively high variable (La/Yb) N values (1.38-11.79) and evidently negative Eu anomalies (Eu/Eu* = 0.07-0.35). The samples have high initial 87 Sr/ 86 Sr (0.708421-0.715698), with negative ε Nd (t) (− 0.53 to − 3.57) and ε Hf (t) (− 0.4 to − 3.2) values, and the Nd and Hf of two-stage model ages are 1.