We report results of 10Be distributions in two continental sequences, a profile of loess-palaeosols and a series fluvial-lacustrine sediments from the Yushe basin, North China, that extend back to 5.4 Ma. 10Be concentrations range from 48.1 to 16.4 × 107 atoms/g in the loess-palaeosol sequence and from 4.2 to 1.0 × 107 atoms/g in the fluvial-lacustrine sequence. The 10Be concentrations show defined decay trends over the interval 1.4 to 5.4 Ma, with an excellent fit to the loess-palaeosol section for the period 1.4-2.8 Ma. The overlap between 10Be and palaeomagnetic time scales is generally good over all the studied sequences. Two major enhancements in the 10Be concentrations were identified at about 1.4 and 3.6 Ma. Climatic information for the area studied, gained from pollen analysis of the fluvial-lacustrine sequence, over the period of 1.8-5.1 Ma, shows an interesting and striking coincidence with 10Be flux trend. The discontinuity in 10Be flux at about 3.6 Ma is associated with an increase of the subtropical pollen components.
ASJC Scopus subject areas
- Global and Planetary Change
- Ecology, Evolution, Behavior and Systematics