1�� College of Earth Sciences��Jilin University��Changchun 130061��China; 2�� ��esearch Center of Palaeontology �� Stratigraphy��Jilin University��Changchun 130026��China

Based on the study of LA- ICP- MS zircon U- Pb geochronology and whole- rock geochemistry for the Luojiazhuang diorite porphyries in Menying��western Shandong��the analyzed zircons exhibit oscillatory growth zoning in the cathodoluminescence images and have high Th/U ratios (0.15-1.53)�� indicating a magmatic ori- gin�� In addition��most of the zircons have narrow metamorphic edges��suggesting that late metamorphic events may exist�� The youngest group of magmatic zircon 207 Pb/ 206 Pb ages ranging from 2 384 Ma to 2 234 Ma��yiel- ding a weighted mean age of 2 353 ±14 Ma��which represents the forming age of the diorite porphyries��as the Early Paleoproterozoic�� Geochemically��the samples are characterized by low SiO 2 (54.54% and 55.47%)�� high MgO (5.22% and 5.49%) and Mg # values (58 and 59)�� Moreover��they show enrichment of light rare earth elements and large ion lithophile elements (��b��Ba and K)��depletion of heavy rare earth elements and high field strength elements (Nb��Ta��Zr and Hf)��positive anomaly of Pb��and negative anomaly of Ti�� The fact implies that the Luojiazhuang diorite porphyries might derive from partial melting of enriched lithospheric mantle and mixed with an amount of continental crust material�� In summary��they may form in the compression tectonic setting that stretching along the east- west direction at the North China Craton in the Early Paleoprotero- zoic��