ZIRCON U-Pb DATING AND GEOLOGICAL IMPLICATION OF THE JINGOU GRANITE IN YILAN AREA, EASTERN HEILONGJIANG PROVINCE

The LA-ICP-MS U-Pb dating is researched for zircon from the Jingou granite in Heilongjiang rock group, which occurs in Yilan area of the Eastern Heilongjiang Province, to identify the formation age and tectonic setting of the Heilongjiang rock group. The results show that the zircon in the sample of D2279 has a clear growth zoning, with Th/U ratios mostly between 0.1 and 1, belonging to typical magmatic zircons. The ²⁰⁶Pb/²³⁸U weighted average age is (261.18±0.74) Ma (n=20, MSWD=0.66), which represents the crystallization age of the rock. The definition of the age of Jingou granite not only defines the forming age of Heilongjiang rock group, but also provides new evidence for further exploration of the Late Paleozoic tectonic evolution of Jiamusi block.