Geochronology and geochemistry of single-grain zircons; simultaneous in-situ analysis of U-Pb age and trace elements by LAM-ICP-MS
Geochronology and geochemistry of single-grain zircons; simultaneous in-situ analysis of U-Pb age and trace elements by LAM-ICP-MS
European Journal of Mineralogy (October 2000) 12 (5): 1015-1024
Simultaneous in-situ analysis of U-Pb age and 26 trace elements for single-grain zircon using the LAMICPMS technique was successfully achieved in this study. The precision of analysis is 1 to 3% for (super 207) Pb/ (super 206) Pb isotopic ratios, 2 and 8% for (super 206) Pb/ (super 238) U ratios and 5 to 15% for most of the other trace elements. The concordia U-Pb and the mean (super 206) Pb/ (super 238) U ages for zircon grain of 1800 Ma to 150 Ma by LAM-ICP-MS spot analysis are in good agreement within analytical errors with the TIMS and SHRIMP result. All zircon grains are uniquely LREE-depleted in chondrite-normalized REE patterns. Zircon formed in mantle-derived magmas is significantly different from that of granitoids with regard to contents of many trace elements (i.e., U, Th, Sigma REE, Y, Nb and P) and REE patterns (i.e., Nd/Yb ratio and Ce and Eu anomalies). This combined geochronological and geochemical investigation provides valuable information on timing and genesis of zircon.