| In the recent decade, with the advance of the global orogenic event at 2.1-1.8Ga, the Columbia super-continent has become more and more well-recognized and known. Many geologists have studied its amalgamation and breakup and obtained important advances. While, the advance on the basemental tectonic of North China Craton (NCC) is that the basement of the NCC could be divided into Eastern Block, Western Block and the Central Orogenic Belt between the two blocks. At about 1.85Ga, the collision between the Eastern and Western Blocks along the Central Orogenic Belt, leading to the ultimate amalgamtion and cratonization of the NCC.Liaoji Area, located to the east of the Tanlu Fault zone in the eastern NCC, includes the Longgang terrain in the north which is adjacent to Xing-Meng orogenic belt, Liaonan and Rangnim Blocks in the south. The Rangnim Block will not be discussed because of a few data. Paleoproterozoic metamorphic rocks, named as "Liaohe Group" in the Liaodong and "Ji'an Group and Laoling Group" in the Jinan area, are widespread throughout the area with emplacement of Paleoproterozoic granitic plutons. However, there are still controversial on the stratigraphy, tectonic setting and geochronologic frame of the metamorphic rock. In this paper, we present the geochronology of the Paleoproterozoic metamorphic rocks from a typical area-The Tonghua area, to resolve the problem. Paleoproterozoic metamorphic rocks are widespread in the studied area, including metamorphic volcanics, metamorphic sedimentary rocks and Paleoproterozoic granites. Although studying had been done since 1830's, there was not systematic geology material untill 1970's. Since 1980's, the Institute of Geology and Mineral of Tianjin, Changchun College of Geology, Shenyang Institute of Geology and Mineral Resources, Jilin Bureau of Geology and Mineral and other units, as well as some scholars, had studied thoroughly, and proposed different theories and thoughts. Recently, with adavance of the study of Paleoproterozoic metamorphic rocks all over the world, especially the important development of Paleoproterozoic metamorphic rocks of NCC, it obviously shows flaws of study on the Tonghua area. Many basic geological problems about Paleoproterozoic metamorphic rocks in the Tonghua area need to be resolved urgently, including: 1) the primary sedimentary sequence and sedimentary besement of Paleoproterozoic metamorphic rocks; 2) the precise dating, petrogenesis, tectonic setting, petrological progress of Paleoproterozoic granites; 3) the geochronology of metamorphism; 4) the crustal evolution during Paleoproterozoic. Geochronological frame of Paleoproterozoic tectonic-magmatic event is fundamental to answer the above questions and provides new evidence to understand the Paleoproterozoic crustal evolution. On the basis of previous data and study and detailed geologic mapping, we collected samples systemically and then dated the different rocks using TIMS, SHRIMP and LA-ICPMS. The shape characteristics of the zircons, the photos of the transmitted light and the reflected light, and the characteristics of the cathode luminescence image, give the detailed structure of the zircon. The results give the geochronological frame of tectonic-magmatic event as below. In early stage (2.18Ga-2.16Ga), mafic-ultramafic rock of Chibaisong pluton and syenite-granite of Qianzhuogou pluton emplaced in an extensional setting. In late stage (1.87Ga-1.85Ga), large scale of granitic plutons, such as Qinghe pluton, Wolongquan pluton and Shuangcha plutons, emplaced in an orogenic setting with regional metamorphism. Between the two stages, volcanic activities happened simultaneously and formed the Ji'an Group and Laoling Group fragmentary rocks deposited. In the last stage, the Kuangtonggou syenite pluton emplaced at about 1.83Ga. Geological and geochemical features of granites show that the early mafic-ultramafic rocks of Chibaisong pluton have high platinum group element contents, while Qianzhuogou syenites and granites have similar characteristics to A-typ...
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