U-PB CHRONOLOGICAL CHARACTERISTICS OF MESOPROTEROZOIC LA-ICP-MS DETRITAL ZIRCONS IN THE XIONG’ER RIFTING TROUGH AND ITS PALEOENVIRONMENT ANALYSIS.

In order to understand the sedimentary age and geotectonic environment characteristics of the Ruyang Group in geological history, this study, with the LA-ICP-MS method, focuses on the study of U-Pb isotope geochronology and geotectonic environment analysis of detrital zircons in the bottom of Xiaogoubei Formation of Ruyang Group in Daimeishan of Henan. Results show that the ages of detrital zircons of Xiaogoubei Formation range from 1720 Ma to 2727 Ma, the youngest detrital zircon age near the harmonic line is 1720 ±65 Ma, the main peak age is 2547 Ma, and the second peak ages include 2178 Ma and 1832 Ma. Therefore, we consider that the lower age limit of Xiaogoubei Formation is ~1720 Ma; the sediment sources of Xiaogoubei Formation mainly come from the geological bodies of the interior of the North China craton in the late Neoarchean, early Paleoproterozoic, middle Paleoproterozoic, late Paleoproterozoic and early Neoproterozoic. At the same time, the detrital zircon age of samples has a good response relationship with the Precambrian geological events in North China Craton, which reveals the then construction environment. [ABSTRACT FROM AUTHOR]