Abstract：Gongyi is the earlist discovered site of the karstic bauxite in Benxi formation in Henan province, and it is also the main component of bauxite metallogenic belt in West Henan. However, its bauxite material sources is not clear. In this study, samples from pisolitic-oolitic bauxite were selected. Petrographic observation, X-ray diffraction analysis and LA-ICP-MS detrital zircons U-Pb dating were conducted for data analysis. The results show that main mineral components of bauxite are diaspora, anatase and illite. The detrital zircon U-Pb ages of the sample can be divided into two groups. The first group mainly is early Paleozoic magmatic zircons ( accounted for 86%) with the age ranges 393—484 Ma and the peak value is ca. 442 Ma. The second group mainly is Precambrian magmatic zircons or metamorphic growth magmatic zircons ( accounted for 14%) with the age ranges 555—2714 Ma and has three peaks, ca. 901 Ma, ca. 1 718 Ma and ca. 2 440 Ma. The detrital zircons with early Paleozoic ages mainly derived from the Caledonian medium-acid granitic intrusive rocks of North Qinling orogeny. The detrital zircons with Precambrian ages might derive from metamorphic formations of North Qinling orogeny. The both types of aforesaid rocks were denuded together and provided sources for bauxite of Benxi formation in the study area. The reason for lack of late Paleozoic detrital zircon in bauxite of this area may be related to tectonic location which is far from Inner Mongolia uplift and close to North Qinling orogeny.

Keyword：bauxite of Benxi formation;material sources;detrital zircon;LA-ICP-MS U-Pb dating;Gongyi area;