金华北山洞穴水地球化学变化特征及气候指示意义

为揭示洞穴水地球化学变化特征及其气候指示意义，从2014年5月到2015年4月对金华北山双龙洞和二仙洞洞穴水进行了连续12个月的观测分析，并结合当地气温和降雨数据，得到以下结果:（1）由于受上覆岩土作用、植被、运移路径等因素的影响，不同滴水点的离子浓度变化有所差异，常年性滴水点（除Ca²⁺外）阳离子平均浓度均大于季节性滴水点、瀑布水和池水；（2）金华北山洞穴水的Ca²⁺，Mg²⁺，Ba²⁺，Sr²⁺浓度变化具有明显的季节变化特征，总体上呈现出雨季高、旱季低的特点，5—8月和次年1—4月随着降雨量的增多而升高，9—12月由于外界降雨少而处于较高的值，外界干湿是影响阳离子浓度变化的主要因素；（3）洞穴水中Mg/Ca比值对外界干湿有指示意义，但也受气温的影响；而Sr/Ca，Ba/Ca比值除了受降雨影响，还受其他因素的影响。

Cave Water Hydrogeochemical Characteristics of Jinhua North Mountain Caves and Its Climate Implications

In order to reveal the geochemical characteristics of cave waters and its climate implication, we have monitored cave waters in Jinhua Beishan Mountain caves from May 2014 to April 2015. Combining with the local data of temperature and precipitation, we got the following conclusions. (1) Affected by overlying rock, vegetation, flow path and other factors, different drip points have different ion concentrations, ion concentrations (except Ca²⁺) of perennial drip point were higher than the seasonal average dripping point, waterfall and pond. (2) Trace element ion concentrations of cave water in Jinhua North Mountain caves showed seasonal variation characteristics that the ion concentrations were low in dry season, were high in rainy season, and increased with the precipitation from May to August and the following year from January to May, keeping the high values from September to December due to the decrease of outside rainfall, dry or wet condition outside is the main factor affecting ion concentration. (3) Mg/Ca ratio of cave water implicates the wet or dry condition outside, but also it is affected by temperature. The ratios of Sr/Ca and Ba/Ca were not only affected by the precipitation, but also were affected by the interference of other geological and hydrological factors.