Geochemical characteristics of REE in the Late Neo-proterozoic limestone from northern Anhui Province, China

Ten representative limestone samples [six from Wangshan Formation (WL) and the other four from Gouhou Formation (GL)] were collected from outcrops of the northern Anhui Province, and REE concentrations in limestone were measured by ICP-MS. The depositional environment and source of the REE were analyzed, and the results implys that the total REE of samples are low compared with the recent marine sediments, which range from 9.61 to 54.18 mg/kg and an average of 22.93 mg/kg. The PAAS-normalized REE+Y patterns of limestone are characterized by (1) light REE depletion in WL and enrichment in GL with the values of (Nd/Yb)SN ranging form 0.65 to 0.91 and 1.12 to 1.46, respectively; (2) light negative Ce anomaly (0.85-1.02) and positive La anomaly (0.92-1.27); and (3) both Eu (0.91-1.23) and Y (1.42-2.38) expressing light positive anomaly. The character indicated that the depositional environment was oxygenated, with infection by the hydrothermal activity and contamination of detritus. © 2014 Science Press, Institute of Geochemistry, CAS and Springer-Verlag Berlin Heidelberg.