『Abstract
Though considerable studies concerning past climate changes in
the Xinjiang, northwest China, have been performed, Holocene climate
changes of this area are still poorly documented and understood.
In this study, we emphasize the potential of geochemical elements
in sediments for indicating the chemical weathering intensity
(CWI) of Bakol Lake catchment during the Holocene. The results
indicate that the CWI represented by ratios of (Ca+Mg+Na+K)/Al,
Ca/Mg, Ca/Al, Mg/Al, Si/Al, Mn/Al and Ca/Al, has the potential
to reflect past climatic conditions. Three weakened CWI periods,
i.e., from 9400-7600 cal a BP, from 6000-5000 cal a BP and since
2000 cal a BP afterwards, and two strengthened CWI periods, i.e.,
from 7600-6000 cal a BP and from 5000-4000 cal a BP, are revealed.
In combination of multi-proxy records including carbonate δ18O
and δ13C, total carbonate content, as well as total
organic carbon, we find the thermal conditions possibly played
an important role in the CWI of lake catchment, with a warmer
climate favoring stronger CWI and vice versa. In contrast, the
moisture conditions appear less influence on the CWI. This new
result is expected to be helpful for strengthening our understanding
of the spatial and temporal patterns of Holocene climate changes
in the westerly influenced region.
Keywords: Lake Barkol; Geochemical elements; The westerly; Chemical
weathering intensity; Holocene climate』
1. Introduction
2. Regional setting
3. Material and methods
4. Results
4.1. Chronology
4.2. Variations of major and trace elements
5. Potential climatic implication of major and trace elements
6. Variations of catchment CWI and climate in the past 9400 years
7. Conclusions
Acknowledgements
References