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Chronological analysis is the basic premise for paleoenvironmental research on lake sediment cores. It mainly employs bulk organic matter as a mixed dating material, although terrestrial plant remains are believed to provide reliable radiocarbon (C-14) ages. C-14 reservoir effects (REs) are generally problematic in establishing a final chronology and are usually recorded in aquatic macrophytes by the incorporation of dissolved inorganic carbon in high-altitude lakes of the Tibetan Plateau. We present a typical case of a 5.48 m-long core sampled from Chibuzhang Co, a lake in north Tibet, China, which contained two obvious obstacles: high REs and age reversals. The C-14 RE was recently as much as similar to 3500 years in the upper part according to total organic carbon (TOC) C-14 ages and related dating from (210)Pbe(x,) activity. It notably changed during the climatic transition to the Holocene due to carbonate input from catchment erosion and glacial meltwater, resulting in reversed C-14 ages in the lower section of the core. C-14-dead carbon (or old carbon) dissolved in lake water was incorporated in the dating materials, as inferred from the C-14 ages of plant samples. By combining data on grain size and carbonate content changes, two sedimentary units were identified with a boundary at 390 cm depth. These were used to estimate individual sediment accumulation rates (SARs) for the final age-depth models, instead of using a constant RE-corrected chronology. Our results provide an environmental history of similar to 12.7 kyr in a long sediment core, based on an optimized SAR model of conventional C-14 ages, which is supported by related lacustrine records and Bacon models. Use of separate C-14 SAR analyses can solve the problem of age inversion in sediment cores, as sedimentological chronology analysis.