14C Chronostratigraphy for Qinghai Lake in China

• DOI: 10.2458/56.16470
• Publication Date: 2014-01-15T19:14:40Z
• Authors: Weijian Zhou; Peng Cheng; A J Timothy Jull; Xuefeng Lu; Zhisheng An; Hao Wang; Yizhi Zhu; Zhenkun Wu
• Keywords: Silt; Chronostratigraphy; Accelerator mass spectrometry; Lithology; Bedrock; Loess plateau; Lithostratigraphy

Radiocarbon accelerator mass spectrometry (AMS) techniques were used to date total organic carbon and plant seeds in the lFs core sequence (36°48′N, 100°08′E) from Qinghai Lake, China. This was drilled ∼18 m into Lake sediments as part of an international cooperative research project, “Scientific Drilling at Northeastern Tibetan Plateau: High-Resolution Paleoenvironmental Records Eastern Asia Linked Global Change,” which began 2004. Based on differences lithology content (TOC) lFs, divided 3 sections for age-modeling purposes: upper ∼499 cm lacustrine silty clay clay; middle unit with silt layers 499–901 cm; lower 901–1861 clay, loess-like silt, fine sand layers. Three different approaches are applied reservoir age problem. First, a simple linear regression gives offset 1342 yr. If is three sections, regressions can be separately segments, results estimate average hardwater effect ∼135 yr BP surface section up 499 cm. extrapolated deeper these imply higher those two may much 1143 2523 yr, but this assumes that there no discontinuities core. A third approach using wiggle-matching gave 196 study concludes complex, new data add our understanding 14 C chronology last 32 ka.