PROGRESS IN GEOGRAPHY ›› 2015, Vol. 34 ›› Issue (7): 909-917.doi: 10.18306/dlkxjz.2015.07.012

• Geomorphology and Quaternary • Previous Articles     Next Articles

Supergene geochemical elements of swampy basin in the subtropical monsoon region: a case study of Dingnan Dahu in Jiangxi Province

Zhiqiang WEI, Wei ZHONG*(), Yongqiang CHEN, Lingling TAN   

  1. School of Geography Science, South China Normal University, Guangzhou 510631, China
  • Received:2014-11-01 Revised:2015-04-01 Online:2015-07-10 Published:2015-07-10
  • Contact: Wei ZHONG


Geochemical elements of the lacustrine-swamp sediments are very sensitive to climate change. This study focused on the geochemical elements of the Dingnan Dahu swamp, Jiangxi Province and extracted three main component groups by using the principal component analysis method combined with related climate proxies, such as total organic carbon (TOC), organic carbon isotope (δ13Corg), median grain size (Md) and chemical index of alteration (CIA). Base on these element groups, we interpret how different geochemical elements respond to variant climate conditions and their behavior patterns. The result shows that the first principal component (PC1), includes the elements of Al2O3, TiO2, SiO2, Nb, Rb, Ga, Ba, S, and so on, indicates the weathering intensity of the lake basin; the second principal component (PC2), includes the elements of Co, Zr, and Hf, indicates hydrodynamic conditions of the Dingnan Dahu swamp; and the third principal component (PC3), includes the elements of Sc, Cu, U, and V, is heavily affected by the organic matter of the marshland. The curve of PC1 is similar to CIA, and higher loadings of PC1 suggests a warm and wet climate. The variation trends of PC2 and PC3 are similar to Md and TOC(and δ13Corg), respectively, and the higher loadings of PC2 and PC3 both suggest a cold and dry climate. The origin of this lacustrine deposit was mainly the local weathered products washed by surface runoff under the condition of warm and wet climate and strong chemical weathering. However, during the cold and dry periods, strong winter monsoon might have carried dust from local weathered products and deposited to the basin as well.

Key words: Dingnan Dahu, geochemical elements, principal component analysis, climate change, sedimentary source