This paper explores the influence of the local meteoric conditions, the overlying soil on the concentrations of Ca, Mg, and St, and the ratios of Mg/Ca, Sr/Ca, and Mg/Sr in soil infiltrating water （SIW）. An in situ ...This paper explores the influence of the local meteoric conditions, the overlying soil on the concentrations of Ca, Mg, and St, and the ratios of Mg/Ca, Sr/Ca, and Mg/Sr in soil infiltrating water （SIW）. An in situ monitoring program was carried out above the Furong Cave throughout 2010 to collect data on SIW, monthly temperature and rainfall, and the geochemical com- position and granularity of soils. The discharge of SIW responded quickly to the local rainfall, and its residence time was the primary factor affecting the Ca, Mg, and Sr content of the SIW. The high concentrations of Ca, Mg, and Sr in the SIW during April should be attributed primarily to the prolonged residence of SIW in the soil during the local dry seasons of winter and early spring. The maximum Mg/Sr ratio also occurred in April. The ratio of Mg/Ca in SIW is positively correlated with pro- longed residence time and with high temperatures, which do not strongly affect the ratio of Sr/Ca. The Mg/Ca ratio was lowest when the Sr/Ca ratio was highest because plant metabolism increased the absorption of Ca and Mg, but not St, and also be- cause higher temperatures enhanced the dissolution of Mg more than that of Sr. These different responses of Mg and Sr to temperature increases resulted in high Mg/Sr ratios during July and August.展开更多
基金supported by National Natural Science Foundation of China(Grant Nos.41302138,40971122,41030103 and 41172165)the Fundamental Research Funds for the Central Universities of Southwest University(Grant Nos.XDJK2013A012 and XDJK2009C106)State Key Laboratory of Loess and Quaternary Geology,Institute of Earth Environment,Chinese Academy of Sciences(Grant No.SKLLQG1310)
文摘This paper explores the influence of the local meteoric conditions, the overlying soil on the concentrations of Ca, Mg, and St, and the ratios of Mg/Ca, Sr/Ca, and Mg/Sr in soil infiltrating water （SIW）. An in situ monitoring program was carried out above the Furong Cave throughout 2010 to collect data on SIW, monthly temperature and rainfall, and the geochemical com- position and granularity of soils. The discharge of SIW responded quickly to the local rainfall, and its residence time was the primary factor affecting the Ca, Mg, and Sr content of the SIW. The high concentrations of Ca, Mg, and Sr in the SIW during April should be attributed primarily to the prolonged residence of SIW in the soil during the local dry seasons of winter and early spring. The maximum Mg/Sr ratio also occurred in April. The ratio of Mg/Ca in SIW is positively correlated with pro- longed residence time and with high temperatures, which do not strongly affect the ratio of Sr/Ca. The Mg/Ca ratio was lowest when the Sr/Ca ratio was highest because plant metabolism increased the absorption of Ca and Mg, but not St, and also be- cause higher temperatures enhanced the dissolution of Mg more than that of Sr. These different responses of Mg and Sr to temperature increases resulted in high Mg/Sr ratios during July and August.
