Geochemical characteristics and isotope chronology study of the Banqiao granodiorite in the eastern part of North Huaiyang

The Banqiao granodiorite in the eastern part of North Huaiyang, which consists mainly of granodiorite, is an important component of the Lingjiachong complex. The Banqiao granodiorite is characterized by meta-aluminum, rich alkali, high K and low Ca,suggesting that it belongs to the high K calc-alkalic series. Medium REE content, high(La/Yb)_N and HREE/LREE ratios, distinct HREE depletion relative to LREE, and weak negative Eu anomalies indicate that the Banqiao granodiorite belongs to a LREE-enriched plutonic rock. Large-ion lithophile elements(LILE), such as Rb, Ba, K, La and Nd, are significantly enriched, while high field strength elements(HFSE), such as Nb, Ta, Ti and P, are depleted. LA-ICP-MS zircon U-Pb dating yields a ²⁰⁶Pb/²³⁸U age(129.0±1.9 Ma)for the Banqiao granodiorite, indicating that it formed in the Late Yanshanian and likely was the product of the Early Cretaceous magmatic activity. Based on the regional geological background of the study area and geochemical tectonic environment discrimination in this study,it can be concluded that the Banqiao granodiorite formed in the post-collision extensional tectonic setting.