Geological and geochemical characteristics and SHRIMP U-Pb zircon dating of the Yinglingshan granite and its xenoliths in Yishui County, Shandong

The Yinglingshan granite, which is mainly distributed in the southeast of the seat of Yishui County, is one of the most important component parts of the Neoarchean Yishui magmatic complex. The gneissosity of granite strikes NE and dip S at 40-50°. The granite is intruded into the Yishui Group-complex composed of a metamorphic rock association of two-pyroxene amphibolite - biotite-plagioclase fine-grained gneiss – two-pyroxene-plagioclase gneiss, and its northern margin is in contact with the Mashan, Xueshan and Dashan granite bodies, while its southeast part is in contact with the Linjiaguanzhuang rock body. The rock is medium to coarse-grained and slightly gneissoid and contains abundant xenoliths. The contents of SiO2 range from 73.36 to 74.44 wt% with K2O>Na2O>CaO. The total content of rare earth elements (REE) are low, varying from 22.25 to 88.82 ppm, and there are obvious fractionations between HREE and LREE. The La/Yb ratios vary from 11 to 47. The rock is enriched in large-ion lithophile elements such as K, Rb and Ba and high-field strength elements such as Er and Hf and depleted in Sr, Ta, Nb and P. Positive Eu anomalies are weak to moderate. So the rock is compositionally potassic granite. The zircon SHRIMP U-Pb dating of samples YS06-30 and YS06-48 yield 2530±7 and 2531±8 Ma respectively, indicating a Neoarchean age.