南方结晶岩区天然矿泉水水文地球化学过程研究——以广东省中山市为例

Study on Hydrogeochemical Process of Natural Mineral Water in Southern Crystalline Rock Area—— Taking Zhongshan City in Guangdong Province as an Example

摘要:

广东省中山市结晶岩地区富含优质的低钠低矿化度偏硅酸型矿泉水。本文基于区域地质背景及主要水体的水化学测试结果，对该地区的天然矿泉水开展了水文地球化学过程研究，包括水文地球化学特征分析、主要成分来源分析、矿泉水年龄分析以及水化学的反向模拟等。对比分析结果显示：结晶岩区的矿泉水与普通民井水和河湖水等具有近似的形成条件，但硫酸根、氯离子和镁离子浓度偏低；矿泉水与地热水的形成条件则存在较大的差异，地热水与海水存在明显的混合作用。而矿泉水主要组分的相关性分析和反向模拟结果表明：矿泉水化学组分的来源除了与含水系统的造岩矿物密切相关外，还与母岩风化或交代蚀变矿物密切相关，在水循环过程中溶滤了碳酸盐、硫酸盐和岩盐等矿物，矿泉水特征组分偏硅酸主要源于斜长石水解作用，与二氧化硅相关矿物关系不大。在矿泉水的形成过程中，碳酸平衡体系起着重要作用，水化学的形成需要有充足的二氧化碳气体，导致此类微矿化水多数呈弱酸性反应。本研究为进一步深入研究南方结晶岩地区微矿化水的形成机制提供了参考依据，对类似的矿泉水资源勘查评价具有一定的指导意义。

Abstract:

Metasilicic acid mineral water with high quality low sodium and low salinity is rich in the crystalline rock area in Zhongshan city of Guangdong province. Based on analysis of regional geological background and hydrochemistry test results of main water bodies, hydrogeological process of natural mineral water in this area has been carried out, including hydrogeochemical characteristic analysis, main component source analysis, age analysis of mineral water and reverse simulation of hydrochemistry. As showed by the results of comparative analysis of water quality components in different water bodies, mineral water in the crystalline rock area has similar forming conditions with ordinary drinking water and river or lake water, but the concentration of sulfate, chloride ion and magnesium ion is relatively lower, and the formation conditions between mineral water and geothermal water are quite different. Tere is obvious mixing action between geothermal water and seawater. While the results of correlation analysis of mian components of minal water and reverse simulation show that the source of chemical components of mineral water is not only closely related to the rockforming minerals of the waterbearing system, but also to the weathering or metasomatic alteration minerals of theoriginal rock. In the process of water circulation, carbonate, sulfate and rock salt are dissolved and filtered. The metasilicic acid of mineral water is mainly due to the hydrolysis of plagioclase, and has little relationship with silica related minerals. At the same time, carbonic acid equilibrium system plays an important role in the formation of mineral water. The formation of hydrochemistry requires sufficient carbon dioxide gas, which leads to the weak acid reaction of most of these micromineralized water. This study will provide some references for further study on the formation mechanism of micromineralized water in the southern crystalline rock area, and has guiding significance for the exploration and evaluation of similar mineral water resources.