Paleolimnology of Qilu Hu, Yunnan Province, China.
Qilu Hu is a large (A = 36.9 km2), shallow (zmax = 6.8 m) lake that lies at an elevation of 1797 m above msl on the Yunnan Plateau, southern China. Lake waters are hard (Mg = 3.2m eq L−1, Ca = 1.3 meq L−1 ), fresh (conductivity = 380 μS cm −1), and productive (Secchi < 40 cm). An 11-m sediment core has a basal 14C age of 30960 ± 860 B.P. Sediments between 11 m and 6 m are high in % dry weight, rich in clay components Al2O3, Fe2O3, K2O, MgO, and low in organic C (≤6.1%), carbonate-C (<1.0%), total N (<3.2 mg g−1), and total S (<-1.7 mg g−1). Diatoms and pollen indicate open-water conditions between 9.0 m and 6.0 m (1342011790 B.P.). Above 6.0 m, CaCO3 and organic matter concentrations increase relative to clastics. The transition marks a change to shallow-water conditions as inferred from diatoms and pollen, and probably reflects a shift to drier climate. Uppermost (80-0 cm) red clays were deposited rapidly, probably as a consequence of recent (decades to centuries) riparian disturbances (e.g. agriculture, lake-bottom reclamation, urban development). Dates assigned to events in the Qilu Hu profile are tentative because of potential hard-water-lake error.
Brenner, M., Dorsey, K., Xueliang, S., Zuguan, W., Ruihua, L., Binford, M.W., & Whitmore, T.J. (1991). Paleolimnology of Qilu Hu, Yunnan Province, China. Hydrobiologia, 214(1), 333-340. doi: 10.1007/BF00050968.
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