Human impact overwhelms long-term climate control of weathering and erosion in southwest China
|Author(s)||Wan Shiming1, Toucanne Samuel2, Clift Peter D.3, Zhao Debo1, Bayon Germain2, 4, Yu Zhaojie5, Cai Guanqiang6, Yin Xuebo1, Revillon Sidonie7, Wang Dawei1, Li Anchun1, Li Tiegang1|
|Affiliation(s)||1 : Chinese Acad Sci, Inst Oceanol, Key Lab Marine Geol & Environm, Qingdao 266071, Peoples R China.
2 : IFREMER, Unite Rech Geosci Marines, F-29280 Plouzane, France.
3 : Louisiana State Univ, Dept Geol & Geophys, Baton Rouge, LA 70803 USA.
4 : Royal Museum Cent Africa, Dept Earth Sci, B-3080 Tervuren, Belgium.
5 : Univ Paris 11, CNRS, Lab IDES, UMR 8148, F-91405 Orsay, France.
6 : Guangzhou Marine Geol Survey, Guangzhou 510760, Guangdong, Peoples R China.
7 : IUEM, SEDISOR UMR Domaines Ocean 6538, F-29280 Plouzane, France.
|Source||Geology (0091-7613) (Geological Soc Amer, Inc), 2015-05 , Vol. 43 , N. 5 , P. 439-442|
|WOS© Times Cited||79|
|Abstract||During the Holocene there has been a gradual increase in the influence of humans on Earth systems. High-resolution sedimentary records can help us to assess how erosion and weathering have evolved in response to recent climatic and anthropogenic disturbances. Here we present data from a high-resolution (∼75 cm/k.y.) sedimentary archive from the South China Sea. Provenance data indicate that the sediment was derived from the Red River, and can be used to reconstruct the erosion and/or weathering history in this river basin. Accelerator mass spectrometry 14C dating provides direct age control and reveals coherent variations in clay mineralogy, geochemistry, and terrigenous flux, indicative of strong chemical weathering and physical erosion during the mid-Holocene warm period (6400–4000 cal [calibrated] yr B.P.), followed by weakening from ca. 4000–1800 cal yr B.P., and renewed intensification since 1800 cal yr B.P.. Comparison with climatic records from China indicates that precipitation and temperature controlled both physical erosion and chemical weathering intensity before 1800 cal yr B.P.. However, weathering proxies in the offshore sediment indicate recent increased soil erosion. We suggest that enhanced human activity (deforestation, cultivation, and mining) since the end of the Chinese Han Dynasty (220 CE) has overwhelmed the natural climatic controls on erosion in the Red River.|