【作者】 曹云；

【导师】 刘再华； 袁道先；

【作者基本信息】 西南大学 ， 第四纪地质学， 2007， 硕士

【摘要】 重庆是有名的温泉之都，拥有世界罕见的温泉资源。目前，随着社会经济的增长和旅游业发展，重庆正在大力开发温泉资源以发展旅游业。近几年，重庆更是提出“世界温泉之都”的口号，重庆“十里温泉城”工程正在紧锣密鼓的进行中。可见，温泉旅游资源在重庆旅游发展战略中占有十分重要的地位。重庆市北温泉公园位于重庆市北碚区城郊，距今有近1600年的历史，是重庆最有名的温泉地点之一。该公园旅游资源丰富，其中钙华形成的乳花洞和温泉构成北温泉公园的主要景观。北温泉公园现有泉眼8处，温泉水水质属硫酸钙型，含钙量为川东各温泉含钙量首位，水质良好，水量丰富，日出水总量为6000--8636吨，水温36度左右。除此之外，公园中还有由钙华形成的大型钙华台地和钙华洞穴（名为乳花洞），钙华台地厚20米左右，长100多米，宽30～40米，乳花洞钙华体厚度可达10m以上，并且乳花洞出口地段的钙华沉积厚度达20余米，其规模在我国同类景观中是不多见的。旅游业的快速发展将对北温泉景观资源的可持续利用和科学保护提出更高的要求。但是，由于以往对北温泉景观资源的形成条件深入系统研究的程度不够，景观变化受制因素不明，监测系统也未建立，而且，目前对旅游资源的保护研究主要集中在管理方面，而对旅游资源（温泉、钙华）保护所需要的成因研究缺乏，导致研究和掌握其变化缺乏资料，开发保护规划缺少科学依据支持。地热温泉是一种特殊的自然资源，它受地质环境和气候条件所控制，因此有很强的地域性。不同地区的温泉具有不同的物理（如：温度，流量，电导率等）和化学（如：pH，微量元素等）性质，温泉水的这些物理和化学性质不仅是研究地质环境的窗口，也是温泉和钙华开发、利用和保护的重要指标。本研究以重庆市北温泉公园为重点研究区域，通过对温泉水的水化学和同位素以及钙华的同位素和测年研究，并结合研究区相关的自然和地质资料，探讨了北温泉的地球化学特征和它的疗养价值以及钙华的地球化学特征。初步成果有：（1）通过对北温泉温泉水的水化学数据并结合该地的水文地质背景分析，推断其来源可能是大气降水进入含石灰岩的嘉陵江组和雷口坡组（含有石膏）地层的深部，溶解碳酸钙和石膏，并通过地热增温，再通过裂隙以泉水的型式流出地表，这个推断可以从以下分析得到证实：①温泉水的电导率、SO₄^2-、Ca²⁺、Mg²⁺之间的正相关性；②温泉水的硫同位素分析；③温泉水的氢氧同位素分析；④选用温泉水中的SiO₂作为地热温度计分析。（2）北温泉温泉水各指标的时间动态研究表明，水温稳定，受气温的影响较小，电导率和pH值变化幅度都很小，相对较稳定，可见北温泉水质比较稳定；通过对北温泉5号温泉的流量监测发现流量呈季节变化，在丰水季节8月前后的流量明显高于枯水季节3月前后的流量，但总的来说，温泉水的流量在观测时间尺度内受季节影响较小，但是，结合前人的研究资料发现，从较长的一段历史时间来看，由于自然和人为因素的共同影响，北温泉温泉水的水量和水温均呈下降趋势。鉴于过去北温泉因附近挖煤、钻井造成泉水减少的教训，本区在进行总体开发规划时，应划定温泉的保护范围，建议以北温泉温泉水出露区为中心，东西20公里宽、南北15公里长的范围为保护区，在此范围内凡钻井、挖煤等地下工程均应采取措施，避免影响泉水的补给条件。（3）3号泉的各参数指标中除pH值外，其他各项指标(包括水温、电导率、K⁺、Na⁺、Ca²⁺、Mg²⁺、HCO₃^-、Cl^-、SO₄^2-)都明显低于其它7个泉点相应的指标，研究表明是由于地表水的混入造成的，而且地表水的混入也不是恒定的，进入3号泉的地表水在雨季大约为40％左右，而在旱季大约为20％左右。（4）通过将北温泉温泉水中微量元素分为有益组分和有害组分分析得知北温泉温泉水温度适中，酸碱度接近中性，流量丰富，水中可溶性固体含量高，含有十几种对人体有益的且接近或达到医疗效果的微量元素，有害组分基本都在泡浴限量标准之内，可见温泉水的保健效果好，因此很适合作为洗浴用医疗矿泉水。（5）通过对北温泉温泉水的温度和碳同位素值推算出当达到同位素交换平衡时的泉水CO₂气相的碳稳定同位素δ值与纯生物成因CO₂气体的碳稳定同位素组成相差很大，又利用北温泉与四川的黄龙有相似的地质背景条件推测北温泉深部地热成因的CO₂的δ¹³C，进而计算出北温泉深部成因的CO₂占60％之多，可见北温泉钙华起源的CO₂主要来自深部地热系统。（6）利用北温泉三个不同时期沉积的钙华的氧同位素数据分析出北温泉的温泉水水温有过起伏，但现在的水温比几千年前降低很多，呈现历史最低水平。（7）根据矿物饱和指数的计算可知，北温泉的泉水（除3号泉外）均对方解石和白云石为过饱和状态，可见北温泉的泉水对钙华不具有溶蚀作用；关于北温泉乳花洞的成因，作者基于饱和指数的计算结果认为乳花洞是由于过去某个时段有大量钙华沉积时，泉水在岸坡冲泻下来时有个水平初速度，因而沉积的钙华与岸坡之间留有一个空隙，随着沉积钙华的增多，逐渐与岸坡顶部相连，空隙却保留下来，就是我们现在看到的乳花洞。总之，对于乳花洞的成因还需进一步研究。更多还原

【Abstract】 Chongqing is famous city of warm spring, has infrequent warm spring resource in world. Nowadays, Chongqing is energetically exploiting warm spring resource to developing tourism. Especially in recent years, Chongqing put forward the slogan "World City of Warm Spring" and applied itself to the project of "Five Kilometers City of Warm Spring". It is obvious that warm spring resource possessed very important status in tourism development tactic of Chongqing.North Springs which located outskirts of Beibei Chongqing had the history of 1600 years and is one of the best well-known famous state parks in Chongqing. The park has abundant tourism resources, further more, warm spring and Ruhua Cave formatted by travertine are the main sights in it. North Springs have eight mouths of spring, which is SO₄—Ca type and the content of Ca²⁺ is the primacy of all springs in Chuandong, China. The springs water quality is good, water flux is abundant （one day’ gross flux is from 6000 to 8636 ton） and water temperature is 36℃or so. In addition, North Springs have a large-scale travertine mesa and a travertine cave （Ruhua Cave）. Travertine mesa’ thickness is 20 meters or so, length is more than 100 meters and width is 30～40 meters. The thickness of the travertine body of Ruhua Cave is more than 10 meters and of near the exit of Ruhua Cave amount to 20 meters. So, its extent sees little of the same kinds of sights in China.The speediness of tourism will put forward higher request to continuance utilize and scientific protecting of sight resource in North Springs. But, researchers had not deep systematically research the information condition of sight resource in North Springs, not know the restricted factor of sights’ changes, even not establish monitor system. In addition, the research of projecting tourism resource mostly focused on management and was short of the cause of formation which projecting tourism resource （warm spring, travertine） need. So, researching and mastering the change of tourism resource is absent of datum; projecting exploitage and protection is absent of the support of scientific basis.Terrestrial heat and warm spring are especial natural resource, which are controlled by geologic environment and condition, so they have very strongly district characteristic. Warm springs in different area have different physical characters（such as temperature, conductance and so on） and chemical ones （such as pH, trace elements and so on）.Those physical and chemical characters of warm springs are not only the window of studying on geologic environment, but also important index of warm springs’ developing、utilizing and protecting. This paper chose North Springs in Chongqing as emphatical study site and discussed geochemistry characters and recuperative merits of warm spring in addition to geochemistry characters of travertine, by ways of analyzing hydrogeochemistry and isotope of warm spring as well as isotope and dating of travertine, combined with correlative regional geology background, stratum and rock character and mail hydrogeologic conditions of North Springs. The following results have been obtained:（1） According to the results of field measuration and the analysis of lab, combined with correlative regional geology background, stratum and rock character and mail hydrogeologic conditions, the source of North Springs may come from recharge of meteoritic water into deep earth where dissolution of limestone rocks （Jialingjiang and Leikoupo formations, and the later formation is younger and contains gypsum layers） would be occurred, then effused to the earth’s surface. The deduction can be approved by means of the following analysis:①positive relativity among conductivity, SO₄^2-, Ca²⁺, Mg²⁺;②analysing S isotope of warm springs;③analyzing hydrogen and oxygen isotope;④chose SiO₂ of warm springs as Terrestrial heat thermometer.（2） By way of analysis of the seasonal variation of several indexes of warm spring, we found that water temperature of North Springs was stabilized and air temperature had little influence on it, and that conductivity and pH had little change. It indicates that the water quality of North Springs was stabilized. Based on investigating water flux of No.5 spring, we found that water flux had seasonal change（the water flux in rainy season obviously higher than it in dry season.） and was influenced little by precipitation during the period of observation. But, water flux and water temperature of North Springs assumed the drop tendency from long historical period of time because of the conjunct influence of natural and man-made factors. Through the study on protecting North Springs, the author make suggestions that in order to avoid influence of spring water’s recharge condition, it is unwarrantable to make hole、dig coal etc in the protecting district which make the place of appearance of North Springs’s warm spring heat, 20km length range from east to west and 15km from south to north.（3） We found that the low values of Spring No. 3 in Chongqing are attributed to mixing of surface water. The SO₄^2- and Ca²⁺ concentrations in Spring No. 3 show two end-members mixing between the original spring water and river water. It seems that the amount of freshwater contribution to the spring water is related to rainfall. Based on a simple mass balance model of SO₄ concentration and current measurements, the contributions of the surface water to Spring No. 3 are about 40% in the rainy season and about 20% in the dry season.（4） The spring water’s temperature in Beiwen Spring is moderate to medical treatment bath, in addition, warm spring water contain abundant saleratus, so Beiwen Spring has the function of making people beautier, at the same time, warm spring contain manifold trace elements that has the curative effects on many ailments.（5） Methods of automatic hydrochemical logging and in-situ titrating combinited with the measurement of stable carbon and oxygen isotope were used to study the hydrochemical and isotopic characteristics of travertine in North Springs. It was found that the travertine-forming springs have high concentration of calcium and bicarbonate, and accordingly high CO₂ partial pressures. Further analysis on the stable carbon isotopic composition of CO₂ gas in the springs shows that the high pressure of CO₂ is mainly related to a deep-seated CO₂ source, meaning that the North Springs travertine should be thermo-genetic.（6） According to relevant calculations based on differences in stable oxygen isotopic compositions of the travertine depositions formed in different epochs at North Springs, water temperature had risen and fallen and nowadays is the lowest.（7） Based on the results of the saturation exponential of carbonate, warm springs in North Springs （apart from No 3 spring） were all supersaturation to calcite and dolomite, but all were close to equilibrium, so, nowadays, travertine in process of deposit was a fat lot. During the past when the travertine cave formed, the recharge water might penetrate further deep into the limest-one of Jialingjiang formation to dissolve abundant Ca²⁺ and CO₃^-concentrations. The saturated CaCO₃ in the spring water would provide conditions for the formation of the travertine carbona-tes. When the travertine was formed, because of the muzzle velocity with whic-h spring water rushed down, there is space within deposited travertine and the borderline of bank. Along with deposit travertine more and more, it gradually was joined with the top of bank, but the space was retained. This is the form reason of Ruhua Cave. Further investigation on how the cave was formed is needed.更多还原