n-Alkane-based reconstructions of peat accumulations and depositional
conditions at four locations around a shallow maar lake in the Changbai
Mountains, northeastern China
Abstract
A high-resolution n-alkane biomarker study of peat cores from
four locations around the Yuanchi maar lake in the Changbai Mountains of
northeastern China, has revealed different histories of peat deposition
in the closely located sequences, although they experienced the same
paleoclimate changes. Comparisons of the n-alkane distributions
of modern plants around the lake and those in the peat cores suggest
that the disparate peat development patterns in the four sites are the
consequence of different peat-forming communities growing around the
lake. These floral differences were in turn controlled by different
water depths associated closely with the volcanogenic lava- and
tephra-shaped topography of the lake basin. Moreover, the
n-alkane-inferred variations in peat development patterns and
inferred recent climate changes around Yuanchi Lake relate closely to
the histories of volcanic forcing in the tropical Pacific and local
volcanic eruptions of the Changbai Mountains. These events evidently led
to alterations of local climate that affected growth of land plants at
the four locations. Finally, anthropogenic impacts since 1950 CE have
had an additional effect on peat accumulation in the Changbai Mountains
region.