Due to the influence of the CO2 derived from the decay of organic matter in soil and the meteoric diagenesis, δ13C and δ18O values of the carbonates in the weathering profile at the unconformable boundary between the early Cambrian and the late Proterozoic Jingeryu Formation in Ji County, North China are markedly negative, and increase with the distance to the unaltered rocks downwards. In addition, the C-and O-isotopic composition of the carbonates in the strata above and below the weathering profile are different. The characteristics of the C-and O-isotiopic compositions described above can be applied to the recognition of other paleo-weathering crusts and the stratigraphic unconformable boundary associated with them.
Li Renwei,Chen Jinshi,Chen Zhiming. CHARACTERISTICS OF THE C-AND O-ISOTOPIC COMPOSITIONS OF CARBONATES IN THE WEATHERING PROFILE AT THE UNCONFORMABLE BOUNDARY BETWEEN THE EARLY CAMBRIAN AND LATE PROTEROZOIC IN JI COUNTY,NORTH CHINA[J]. Chinese Journal of Geology, 2000, (1): 55-59.