The records and implications of Mg,Sr and Ba in cave water and active speleothems in Jiguan Cave,western Henan Province
REN Xiao-feng
YANG Yan
PENG Tao
ZHAO Jing-yao
ZHANG Yin-huan
NIE Xu-dong
LIU Xiao
LI Jian-cang
LING Xin-you
ZHANG Zhi-qin
Abstract：Speleothems contain a number of suitable proxies reconstructing climate environmental changes, which is a top topic in current research.Due to the variety of sources and complex factors,trace elements are less frequently used than the oxygen isotopes in climate studies.However,they are used to reveal the groundwater runoff in the epikarst overlying the cave with the process and the surface environment.Induc-tively coupled plasma mass spectrometry (ICP-MS)and inductively coupled plasma optical emission spec-trometry(ICP-OES)have been used to analyse the trace elements of Ca、Mg、Sr and Ba in cave water and ac-tive formations in Jiguan Cave during December,2009 and August,2013.Jiguan Cave (33°46′N,111°34′E) is located in Luanchuan county,western Henan Province,which is north of the Qinling ranges-Huaihe River and southeast of Loess Plateau,while at the foot of the northern watershed of the Yangtze River and the Yellow River.It main exposed rocks are Sinian chlorite marbles.Located in the typical east Asian monsoonal zone,the Jiguan Cave area is typically has cold/dry winters and warm/wet summers.More than 50 % of the total annual precipitation occurs in summer.The mean annual temperature and precipitation recorded at a nearby meteorological station are 12.1±0.9 ℃ and 846±181 mm (1957-2009)respectively.In the paper, trace elements such as Ca,Mg,Sr and Ba in cave water and active formations collected in Jiguan Cave were analyzed with ICP-MS and ICP-OES.The Mg/Ca,Sr/Ca and Ba/Ca of cave water varied between 0.2-0.8, (1.2-6.0)×10-3 and (0.3-2.0)×10-3 respectively.Mg/Ca can respond to the environment outside the cave faithfully.The wet-dry condition of the karst system is suggested as the dominant controller of Mg/Ca ratios in cave pool water and underground rivers,whereas the Sr/Ca and Ba/Ca may have nothing to do with precipitation and temperature.The Mg/Ca,Sr/Ca and Ba/Ca ratios in active speleothems varied between (9-50)×10-3 ,(0.1-1.2)×10-3 and (0.8-3.2)×10-3 respectively.Corresponding to that of the water, the opposite trend was observed in Sr/Ca,Ba/Ca and Mg/Ca ratios.This opposite trend may have been in-fluenced by atmospheric dust and surface soil,but there are still unexplained phenomenons worth further re-search.The co-precipitation coefficient constants for Mg/Ca and Sr/Ca between modern carbonate and water were calculated,giving a KSr value of 0.02-0.18 and KMg value of 0.01-0.03.Positive correlation between KMg and cave temperature is faint.
Keywords：speleothemscave dripping watertrace elementJiguan CaveLuanchuan in Henan Province
Publication Date：2014-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：7( 57-63 )