Geochemical characteristics of REE in limestone of the Taiyuan Formation, Paner coalmine and their constraint on depositional environment

Based on a detailed petrologic study, the characteristics of REEs in limestone samples from the Late Carboniferous Epoch Taiyuan Formation in the Huainan Paner coalmine were analyzed. The origin of REEs and the depositional environment of limestone were investigated. Lower concentrations of Zr, Th, Sc, and relatively higher ratios of Y/Ho show that the limestone sediments deposited in a marine environment, with no impact on terrigenous detrital. The characteristics of LREE-depletion, slightly positive La anomaly, positive Y anomaly and high ratio of Y/Ho show that the limestones have similar tendency as the marine carbonate, which indicates that the limestone deposited in a marine environment. However, the Ce anomaly in the limestone samples reflects a transition process of a reducing-oxidizing environment during the deposition. The positive Eu anomaly reflects that the limestone from Taiyuan Formation was formed in a near coastal environment with the input of weathered terrestrial organic matter.