Geochronology and geochemistry of single-grain zircons: Simultaneous in-situ analysis of U-Pb age and trace elements by LAM-ICP-MS

Simultaneous in-situ analysis of U-Pb age and 26 trace elements for single- grain zircon using the LAM-ICPMS technique was successfully achieved in thi s study. The precision of analysis is 1 to 3 % for Pb-207/Pb-206 isotopic r atios, 2 and 8 % for Pb-206/U-238 ratios and 5 to 15 % for most of the othe r trace elements. The concordia U-Pb and the mean Pb-206/U-238 ages for zir con grain of 1800 Ma to 150 Ma by LAM-ICP-MS spot analysis are in good agre ement within analytical errors with the TIMS and SHRIMP results. All zircon grains are uniquely LREE-depleted in chondrite-normalized REE patterns. Zi rcon formed in mantle-derived magmas is significantly different from that o f granitoids with regard to contents of many trace elements (i.e., U, Th, S igma REE, Y, Nb and P) and REE patterns (i.e., Nd/Yb, ratio and Ce and Eu a nomalies). This combined geochronological and geochemical investigation pro vides valuable information on timing and genesis of zircon.