Details

Autor(en) / Beteiligte

• Wu, Duo
• Zhou, Aifeng
• Liu, Jianbao
• Chen, Xuemei
• Wei, Haitao
• Sun, Huiling
• Yu, Junqing
• Bloemendal, Jan
• Chen, Fahu

Titel

Changing intensity of human activity over the last 2,000 years recorded by the magnetic characteristics of sediments from Xingyun Lake, Yunnan, China

Ist Teil von

• Journal of paleolimnology, 2015-01, Vol.53 (1), p.47-60

Ort / Verlag

Dordrecht: Springer-Verlag

Erscheinungsjahr

2015

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• We report mineral magnetic measurements (magnetic susceptibility, anhysteretic and isothermal remanence, magnetic hysteresis and thermomagnetic properties) from a 2.46-m-long sediment core taken in Xingyun Lake, Yunnan, China. Results demonstrate that magnetic minerals in the lake sediment are dominated by stable single-domain (SSD) ferrimagnetic minerals derived mainly from in-washed catchment soil. Magnetic susceptibility increases sharply during the period AD ~500–1050, and the grain size of magnetic minerals decreases. These changes are accompanied by increases in the concentrations of Fe, Ti, Zr and Si, and by decreased tree pollen percentages. δ¹⁸O measures in speleothems from South China demonstrate that climate was relatively uniform during this interval. Documentary evidence, however, indicates a large increase in the human population of Yunnan Province at that time. We conclude that the late Holocene sediment record from Xingyun Lake reflects a dramatic increase in soil erosion that was caused by a growing human population, which in turn was responsible for increased deforestation and agricultural activity. Our results from Xingyun Lake are consistent with sediment magnetic records from Erhai Lake, located near our study site. We therefore conclude that the interval AD ~500–1050 corresponded to a regional-scale increase in the intensity of human activity on the Yunnan-Guizhou Plateau.