万的军,陈洪云,宋磊*,宋超
Faithfully
tracing sources of sediment and then quantifying the flux of each source are
the first-order basis for reconstructing paleoclimate and paleoenvironment
using lake sediments. The budget of various sources contributing to lake
sediment in Lake Qinghai, the largest lake on the Tibetan Plateau, is
controversial. In the previous study, the flux of the dust deposition to the
modern lake sediment was obtained through two-year observations, but estimations
of other sources have some uncertainties due to inadequate data. In this study
our new estimations for the modern Lake Qinghai sediment using new measured
data show (1) that contribution (22.1 ± 5.2%) of the fluvial particulate matter
is of second significance, only about one third of the dust deposition, to the
modern lake sediment, when its quick deposition near river mouths is not
considered, (2) that lacustrine organisms contribute only 5.2 ± 1.1% of the
sediment, but account for ~70% of the organic matter in sediment,