Water and sediment chemistry of Lake Pumayum Co, South Tibet, China: implications for interpreting sediment carbonate
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A combination of water and sediment chemistry was used to investigate carbonate production and preservation in Lake Pumayum Co (altitude 5,030 m a.s.l.), south Tibet, China. We compared the chemical composition of lake water in various parts of the lake with that of input rivers and found that the loss of Ca2+ results from calcite sedimentation induced by evaporation and biogenic precipitation. This is supported by evaporation data from the catchment and δ18O measurements on water. Results suggest that CaCO3 is the predominant carbonate in this lake. There is a positive correlation in the sediments among concentrations of total inorganic carbon (TIC), Ca, total organic carbon (TOC), and total nitrogen, confirming that most carbonates in sediment are endogenic. The Jiaqu River is the largest inflow to Lake Pumayum Co and has a strong influence on both lake water chemistry and sediment composition. The river and lake bathymetry influence carbonate sedimentation by affecting water flow velocity and growing conditions for macrophytes. Different carbon contents and relationships between TIC and TOC in the two long cores from different depths in the lake reveal that hypolimnetic conditions also influence carbonate precipitation and preservation.
KeywordsCarbonate Lake sediments Tibetan Plateau Water chemistry Spatial distribution Lake Pumayum Co
This study was supported by the National Natural Science Foundation of China (Grants No. 40871099), the National Basic Research Program of China (Grant No. 2005CB422002), and the Knowledge Innovation Project of the Chinese Academy of Sciences (KZCX2-YW-146-4). The authors thank two anonymous reviewers for the encouragement and constructive remarks. We also thank Ms. Margaret Joyner and Dr. Mark Brenner for help with improvement of the language. Thanks are also given to J. Gao, D. M Qu, and S. P. Gao from the Institute of Tibetan Plateau Research, Chinese Academy of Sciences, for their great help with laboratory work.
- Bureau of Geology, Mineral Resources of Xizang Autonomous (1993) Region regional geology of Xizang (Tibet). Geological Publishing House, Beijing, p 142 (in Chinese)Google Scholar
- Filippi ML, Lambert P, Hunziker JC, Kubler B (1998) Monitoring detrital input and resuspension effects on sediment trap material using mineralogy and stable isotopes (18O and 13C): the case of Lake Neuchâtel (Switzerland). Palaeogeogr Palaeoclimatol Palaeoecol P140:33–50. doi: 10.1016/S0031-0182(98)00040-6 CrossRefGoogle Scholar
- Gu ZL, Liu JQ, Yuan BY (1993) Monsoon variations of the Qinghai-Xizang plateau during the last 12, 000 years—geochemical evidence from the sediments in Siling Lake. Chin Sci Bull 38:577–581Google Scholar
- Guan ZH, Chen CY, Ou YX, Fan YQ, Zhang YS, Chen ZM, Bao SH, Cu YT, He XW, Zhang MT (1984) The rivers and lakes of Tibet. Science Press, Beijing, pp 162–168 (in Chinese)Google Scholar
- Handra BK (1972) Geochemistry of the Ganges River water. India Geohydro 8:71–78Google Scholar
- Jones BF, Bowser CJ (1978) The mineralogy and related chemistry of lake sediments. In: Lerman A (ed) Lakes—Chemistry, Geology, Physics. Springer, New York, pp 179–227Google Scholar
- Kelts K, Hsü KJ (1978) Freshwater carbonate sedimentation. In: Lerman A (ed) Lakes—Chemistry, Geology, Physics. Springer, New York, pp 295–321Google Scholar
- Schmieder K, Piepho HP, Schröder HG (2005) Patterns of surface sediment composition and their contributing factors in the littoral zone of Lake Constance (Germany). Aquat Sci 67:326–336Google Scholar
- Wang SM, Li JR (1991) Lacustrine sediments—an indicator of historical climatic variations—the case of Qinghai Lake and Daihai Lake. Chin Sci Bull 36:1364–1368Google Scholar
- Yin CL, Tian LD, Yu WS, Gong TL (2006) Variations of stable oxygen isotope in precipitation in the Basin of Yamzho Lake. J Glaciol Geocryol 28:919–924 in ChineseGoogle Scholar