¹⁰Be in continental sediments from North China: Probing into the last 5.4 Ma

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.