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1.
拒马源泉群作为拒马河的源头,受到了较多专家和学者的关注。但这些研究多集中在地下水的水化学、水位动态、泉流量等特征上,对地下水氢氧同位素特征的分析几乎没有,且对北海泉的成因解释多为粗略的定性概述。为了说明涞源北盆地地下水的氢氧同位素特征,详细揭示北海泉的形成模式,首次系统地采集了不同含水岩组的地下水样品,测定了水样的氢氧同位素组分。结果表明:样品点δD和δ18O值均落在区域大气降水线上或附近,大气降水是研究区地下水的主要补给来源;白云岩、灰岩含水岩组高程效应较明显,径流途径长,松散含水层径流途径短,受蒸发作用较强;白云岩、灰岩含水岩组和松散含水层氘盈余d值分别为6.0‰～11.6‰、4.2‰～11.2‰、3.8‰～8.0‰,较大气降水大部分偏小,表明岩溶水和松散孔隙水经历了不同的流动过程;白云岩、灰岩含水岩组从补给区向排泄区各自流动过程中,在小西庄、香炉屯村附近断裂带发生沟通混合,然后在向盆地中心径流过程中受断层阻水上升,上升过程中又接受了松散孔隙水的补给,最后在松散岩层中出露成泉,形成北海泉。在孔隙水混入前,两者的平均补给比例大约为48.4%～57.6%和42.4%～51.6%。 相似文献
2.
Dynamics and anthropogenic impacts of multiple karst flow systems in a mountainous area of South China 总被引：5，自引：0，他引：5
Mingming Luo Zhihua Chen Robert E. Criss Hong Zhou He Huang Zhaofeng Han Tingting Shi 《Hydrogeology Journal》2016,24(8):1993-2002
The Xiangxi River basin, South China, is a steep terrane with well-developed karst features and an important Cambrian-Ordovician aquifer. Meteoric water in this mountainous area features a mean δ18O elevation gradient of –2.4?‰/km. This gradient was used to estimate mean recharge elevations of 760 m for Shuimoxi (SMX) spring, 1,060 m for Xiangshuidong (XSD) spring, and 1,430 m for drill hole ZK03, indicating multiple flow paths in the Cambrian-Ordovician karst aquifer. Mean residence times of 230 and 320 days and ～2 years were estimated for these features, respectively, using the damped running average model that predicts the isotopic variations in groundwater from those in precipitation. Groundwater in the regional karst flow system has the longest residence time, the highest recharge elevation, the longest flow paths, the lowest addition of anthropogenic components, and the greatest amount of water–rock interaction as indicated by its higher dissolved solids, Mg2+ concentrations and Mg/Ca ratios than the springs. In contrast, the local and shallow karst flow systems respond rapidly to recharge events. Artificial tracer tests prove that these shallow karst systems can also quickly transmit anthropogenic contaminants, indicating that they are highly vulnerable to human impacts, which include the enrichment of NO3 –. The intensity of water–rock interaction and groundwater vulnerability are mainly determined by the structure and dynamics of the multiple karst flow systems. 相似文献
3.
Uranium contents and234U/238U ratios have been determined on 29 water samples from the Taiyuan area, Shanxi Province. The results show that the same artesian
aquifer has similar uranium contents and234U/238U activity ratios, and the deeper aquifers have higher A. R. values but lower uranium contents. The A. R. values increase
slightly towards groundwater flow in the artesian aquifers dominated by oxidizing ground waters.
The Lancun Spring and the famous Jinci Spring belong to two different karst groundwater systems, i.e., the east and west karst
groundwater systems. The recharge area of the Lancun Spring should cover the wide limestone outcrops of middle Ordovician
in the northeast. The Ordovician fissure-karst ground water to the Jinci Spring is extensively mixed with fissure water in
Carboniferous-Jurassic formations and seepage water from the Fenhe River. 相似文献
4.
Benjamin W. Tobin Abraham E. Springer David K. Kreamer Edward Schenk 《Hydrogeology Journal》2018,26(3):721-732
An understanding of the hydrogeology of Grand Canyon National Park (GRCA) in northern Arizona, USA, is critical for future resource protection. The ~750 springs in GRCA provide both perennial and seasonal flow to numerous desert streams, drinking water to wildlife and visitors in an otherwise arid environment, and habitat for rare, endemic and threatened species. Spring behavior and flow patterns represent local and regional patterns in aquifer recharge, reflect the geologic structure and stratigraphy, and are indicators of the overall biotic health of the canyon. These springs, however, are subject to pressures from water supply development, changes in recharge from forest fires and other land management activities, and potential contamination. Roaring Springs is the sole water supply for residents and visitors (>6 million/year), and all springs support valuable riparian habitats with very high species diversity. Most springs flow from the karstic Redwall-Muav aquifer and show seasonal patterns in flow and water chemistry indicative of variable aquifer porosities, including conduit flow. They have Ca/Mg-HCO3 dominated chemistry and trace elements consistent with nearby deep wells drilled into the Redwall-Muav aquifer. Tracer techniques and water-age dating indicate a wide range of residence times for many springs, supporting the concept of multiple porosities. A perched aquifer produces small springs which issue from the contacts between sandstone and shale units, with variable groundwater residence times. Stable isotope data suggest both an elevational and seasonal difference in recharge between North and South Rim springs. This review highlights the complex nature of the groundwater system. 相似文献
5.
The Gavbast karstic aquifer located in southern Iran is in direct contact with an exposed salt diapir. To assess the influence of the diapir on the quality of groundwater in the karstic aquifer, electrical conductivity, total dissolved solids, flow rate, temperature and major ion concentrations were measured at 57 sampling sites, including springs, surface waters and wells. A conceptual model of groundwater flow is proposed for the Gavbast karstic aquifer based on the geological setting, water budget, local base of erosion, and hydrochemistry of the sampling sites. The model suggests two subbasins in the Gavbast Anticline draining into two distinct discharging alluvial sections. Unexpectedly, groundwater discharging from the carbonate Gavbast aquifer is saline or brackish and water is of chloride type. The study indicates that the source of salinity of the Gavbast aquifers is infiltration of surface diapir-derived brine into the aquifer. The contribution of the diapir brine in the Gavbast karst aquifer is calculated about 4 L/s, using chloride mass balance. Construction of salt basins to evaporate brine discharging from the diapir springs is proposed to reduce the salinity of karst water. A row of strategically placed wells in the Gavbast karst aquifer would potentially exploit large volumes of fresh groundwater before it is contaminated by the salt. Such low-cost remediation should allow the agricultural exploitation of 40 km2 of currently barren land. 相似文献
6.
Geological structure, recharge processes and underground drainage of a glacierised karst aquifer system, Tsanfleuron-Sanetsch, Swiss Alps 总被引：1，自引：1，他引：0
Vivian Gremaud Nico Goldscheider Ludovic Savoy Gérald Favre Henri Masson 《Hydrogeology Journal》2009,17(8):1833-1848
The relationships between stratigraphic and tectonic setting, recharge processes and underground drainage of the glacierised karst aquifer system ‘Tsanfleuron-Sanetsch’ in the Swiss Alps have been studied by means of various methods, particularly tracer tests (19 injections). The area belongs to the Helvetic nappes and consists of Jurassic to Palaeogene sedimentary rocks. Strata are folded and form a regional anticlinorium. Cretaceous Urgonian limestone constitutes the main karst aquifer, overlain by a retreating glacier in its upper part. Polished limestone surfaces are exposed between the glacier front and the end moraine of 1855/1860 (Little Ice Age); typical alpine karrenfields can be observed further below. Results show that (1) large parts of the area are drained by the Glarey spring, which is used as a drinking water source, while marginal parts belong to the catchments of other springs; (2) groundwater flow towards the Glarey spring occurs in the main aquifer, parallel to stratification, while flow towards another spring crosses the entire stratigraphic sequence, consisting of about 800 m of marl and limestone, along deep faults that were probably enlarged by mass movements; (3) the variability of glacial meltwater production influences the shape of the tracer breakthrough curves and, consequently, flow and transport in the aquifer. 相似文献
7.
娘子关泉域群泉是中国北方最大的岩溶泉,泉域汇水面积达7 436 km2,前人认为:泉域内岩溶水由北、西、南3面向娘子关一带径流汇集,由于娘子关一带下奥陶系燧石团块或条带白云岩相对隔水层隆起,并被桃河侵蚀出露,使岩溶地下水溢出地表成泉群,其主要含水层为中奥陶系含石膏碳酸盐岩。但各泉的水化学、同位素特征有差异,娘子关泉群并不是出自统一源。文章通过水化学、同位素、水文地质剖面等方法研究得出: 娘子关泉域存在两个含水层、三个子系统:中奥陶系灰岩含水层和中上寒武系白云岩含水层;西部奥陶系岩溶水系统、东部奥陶系岩溶水系统和东部中上寒武系岩溶水系统。泉域内城西泉与程家泉出露于中奥陶系下马家沟组泥灰岩之上,含水层为中奥陶系灰岩裂隙、溶隙水,由于区域下马家沟组泥灰岩隆起隔水出露地表成泉,属于东部奥陶系岩溶水系统;坡底泉、五龙泉、河北泉、水帘洞泉、苇泽关泉其补给主要来源于中上寒武系含水岩组,为承压上升泉,属于东部中上寒武系岩溶水系统。 相似文献
8.
Characterization of karst conduits by tracer tests for an artificial recharge scheme 总被引：1，自引：0，他引：1
Challenged by rapidly changing climate in combination with an increase in anthropogenic pressures, karst groundwater resources in the Old Town of Lijiang (OTLJ), SW China, are diminishing. Higher frequency and longer duration of dried-up periods have been observed at the Heilongtan Park (HP) Springs in recent years. Thus, there is an urgent need for an artificial recharge scheme, aimed at replenishing groundwater in the aquifer and increasing the outflow of the springs to ensure effective water resources management. Evaluation of the scheme feasibility, prior to its implementation, is important. In this study, tracer tests were conducted between the recharge area and receiving springs in order to gain insight into the transport mechanisms of karst groundwater and the structural characteristics of the aquifer. Multiple underground flow paths, exhibiting high conductivity between the recharge area and HP Springs, were revealed by the interpretation of tracer breakthrough curves. Three springs considered as the leakages of the scheme were identified. Moreover, the outflow of springs at HP and OTLJ were predicted to be increased by the artificially recharged water after 9.2 and 12.5 days, respectively. Quantitative analysis of tracer recoveries demonstrates that the springs to be recharged and the springs considered as leakages, respectively, share 45 and 55% of the increased outflow. The feasibility of the scheme has been confirmed by the tracer tests. This report provides references for the evaluation of artificial groundwater recharge and protection strategies, particularly in large and poorly investigated karst spring fields.
相似文献9.
煤炭开采后峰峰矿区奥陶系岩溶水硫酸盐演化过程研究 总被引：5，自引：3，他引：2
文章运用水化学和同位素水文学等手段,寻求奥陶系岩溶水硫酸盐演化过程的“指纹”,通过不同含水层间水化学、稳定同位素差异的比对,分析其与上覆含水层间的水力联系和硫动力分馏过程,阐述采矿活动影响下峰峰矿区奥陶系岩溶水硫酸盐的演化过程。研究结果表明:煤矿开采后,峰峰矿区奥陶系岩溶水硫酸盐含量普遍增高,演化特征呈现多样性,存在多种硫动力分馏过程。分馏动力主要来自矿坑水和孔隙水通过导水裂隙的渗漏（越流）补给,以及脱白云石化过程中自身蒸发岩矿物（石膏）的溶解。 相似文献
10.
岩溶大泉是中国北方岩溶地下水的主要天然排泄形式,它们集供水、旅游、生态等功能于一体,是重要的自然资源。自20世纪后期,受自然、特别是人类大规模开发、采煤等活动的影响,有近30%的岩溶大泉断流,其中不乏中外闻名的大泉。十七大以来,各地政府积极响应党中央国务院加强生态文明建设的号召,启动了一些重要断流岩溶大泉复流的生态修复工程。本文根据北方断流岩溶大泉的结构模式与成因,提出了包括利用上游水库蓄水、调节渗漏段河水流量、在河流渗漏段实施人工增补工程、在岩溶地下水强径流带和排泄区采取关井压采、封堵泉口下游自流井、对煤矿带压区进行监控、补给区分区植树造林措施的复流模式;以山西太原晋祠泉为实例,在对各项复流措施效果进行定量优化评价的基础上,得出抬高汾河二库水位至设计标高、关闭岩溶地下水强径流带内白家庄煤矿降压排水井、封堵处置泉口下游自流井是近期经济可行的有效措施的结论;最后利用建立的泉域地下水渗流数值模型,预测实施三项近期措施后,晋祠泉水可望在2年左右的时间实现复流,该结论以期为晋祠泉及北方岩溶区其他同类型岩溶泉水生态复流工作提供示范与参考。 相似文献
11.
Residence time distribution in the Kirkgoz karst springs (Antalya-Turkey) as a tool for contamination vulnerability assessment 总被引：1，自引：0，他引：1
N. Nur Ozyurt 《Environmental Geology》2008,53(7):1571-1583
Lumped parameter modeling of environmental tracer (tritium, CFCs and tritiogenic helium-3) transport in the Kirkgoz karst
springs (Antalya-Turkey) appears to be a useful tool for assessing the vulnerability to contamination. Based on tritium observations
between 1963 and 2000, the springs revealed a mean residence time (MRT) of 120 years. This suggests an active transport volume
of 71 billion cubic meters for the aquifer, a value that is coherent with the estimated void volume of karst aquifer based
on the mass of associated travertine deposits. The CFC-11 and CFC-12 MRTs are in agreement with tritium-based MRT, after correcting
for excess air effect. Excess crustal and mantle helium flux hindered the use of tritiogenic helium-3 as a potential tracer.
The residence time distribution (RTD) indicates a groundwater transport system that is fed by recharges extending back to
past several hundred years. This wide RTD suggests that any recent contamination that may have entered the system could progress
slowly within the entire aquifer but would be unnoticed in the early period because of the dilution effect of uncontaminated
past recharge waters. Once the contamination is recognized, it may last for many centuries ahead even if the contamination
practice is stopped. Thus, control of contaminant release to aquifer and monitoring of contaminant level in Kirkgoz springs
is an immediate task for the associated public health authorities. 相似文献
12.
Nico Goldscheider 《Hydrogeology Journal》2008,16(7):1311-1317
In 1998 and 1999, two multi-tracer experiments were conducted in the artesian karst aquifer of the mineral springs of Stuttgart, Germany. The breakthrough curves (BTCs) monitored at the springs showed very long tails or developed plateau-like concentration levels for more than 200 days. Initially, this observation was qualitatively explained by exchange between cavities with stagnant water and the active conduits. Since then, a new analytical solution for tracer transport in karst aquifers has become available, the “two-region non-equilibrium model” (2RNE), which assumes the presence of mobile and immobile fluid regions, and mass transfer between these two regions. The experiments were thus revisited, and it was possible to provide a more quantitative explanation of the observed behaviour. The new model simulated all BTCs very well, thus confirming the earlier qualitative explanation. The prolonged BTCs can be attributed to intermediate storage in cavities containing quasi-immobile groundwater, and slow release into active fractures and conduits. The results also demonstrate that karst aquifers are not always fast-flushing systems, but contaminants can sometimes remain in immobile fluid regions for long periods. 相似文献
13.
Martin Knez Janja Kogovšek Hong Liu Janez Mulec Metka Petrič Nataša Ravbar Tadej Slabe 《Environmental Earth Sciences》2012,67(1):273-283
In Kunming area (6.8 mio population), two big interventions are in progress: construction of a new airport, the 23 km2 area of which will extend across karst terrain northeast of the city, and extensive uptake of water from karst aquifers for drinking and agricultural use. In the study, an interdisciplinary approach was utilized to demonstrate the need for holistic karstology studies prior to performing extensive interferences in the karst environment. This study included survey of surface karst features and microscopic analyses of rock samples in the area of the new airport location, accompanied by hydrogeological studies and microbiological analyses of two karst drinking water sources in its vicinity (Qinglongdong, Huanglongdong). Results showed the specific characteristics of the subsoil stone forest that indicated a high level of karstification. The direction and characteristics of groundwater flow from the sinking Qiaotou Stream at the margin of the new airport area toward the Huanglongdong Spring were defined with a single tracer test. Additional information about hydrogeological characteristics of the karst aquifer was obtained by individual measurements of physical and chemical parameters of the springs and sinking stream. Selected chemical and bacteriological parameters showed substantial pollution of both springs due to various types of human activities in the catchments. The results of the study pointed to the necessity of taking immediate measures for the springs’ protection and showed the importance of interdisciplinary research when planning anthropogenic activities in the karst. 相似文献
14.
Philippe Meus Pierre Moureaux Sébastien Gailliez Jérémy Flament Francis Delloye Philippe Nix 《Environmental Earth Sciences》2014,71(2):533-541
The implementation of the Water Framework Directive, as well as the forthcoming entry into force of other European water policies focusing on water resources, require a thorough reorganization of groundwater resources monitoring in most European countries. In Wallonia, monitoring programs were initiated in 2005 to control the quantitative and chemical statuses of groundwater bodies, as well as the effectiveness of management plans aimed at achieving environmental objectives. In karst aquifers, springs are preferential monitoring targets even if, as a result of the high heterogeneity of this type of aquifer, the interpretation of time series and spatial data remains a challenge. Since 2006, a “springs” monitoring network has been progressively set up in the southern part of Belgium. Currently, in situ measurements of discharge, temperature, conductivity, turbidity and fluorescence of water are conducted at nine karstic outlets in the Devonian and the Carboniferous limestone aquifers of Wallonia. The main objective of this ongoing research is to evaluate the suitability and the robustness of such standard measurements to discriminate anthropogenic impacts from natural variations, at both short- and long-term scales. Discharge and temperature data revealed being useful in the assessment of regional hydro-climatic trends. Groundwater proved to be a better natural filter for the assessment of long-term climatic changes than mathematical filtering of noisy surface signals. Investigations of such data at a European scale could therefore give additional insight into the impacts of climate change on groundwater resources. Conductivity, turbidity and fluorescence data characterize the particulate, mineral and organic health of water and a better understanding of their natural dynamics could help in the early detection of anthropogenic deviations. However, the current reproducibility of these measurements is too low to ascertain observed trends and fluctuations, and further research is still needed. 相似文献
15.
Impact of karst water on coal mining in North China 总被引：1，自引：0，他引：1
Coalfields in North China encompass more than ten Provinces. They contain six to seven coal seams in the Permo-Carboniferous
strata. The lower three seams account for 37% of the total reserves and are threatened with intrusion of karst water from
the underlying Ordovician limestone. Hundreds of water inrush incidences have occurred, in which a large amount of water suddenly
flows into tunnels or working faces under high potentiometric pressure. Over 50 mines have been flooded over the last 30 years.
Large-scale dewatering or depressurizing of the karst aquifer was considered essential to avoid water inrushes and keep the
mines safely operational. This practice, however, has caused sinkholes, dry springs, water supply shortage, and groundwater
contamination in the surrounding areas. One alternative water control measure is to make full use of the rock layer between
the coal seam and the karst aquifer as a protective barrier to prevent or constrain water flow from the underlying aquifer
into the mines. Grouting is effective when the hydrogeological conditions are favorable to this technique. Proper design of
the grouting program and experience of the contractor are also important for a successful application. 相似文献
16.
奥 陶 系石 灰 岩 是 济宁 煤 田 一 区太 原 组 下 部煤 层 底 板 充水 含 水 层 ,岩 溶 裂隙 发 育 ,富 水 性 较 强,由 于排 泄 条 件差, 天然 状 态下 水质 不 符合 饮用 水标 准 。通 过 群孔 抽 水 试 验,改 变 了地 下 水 的 循环 条 件 ,使 水 质 达 到了 生 活 用 水 导致标 准,为此 区 奥灰 水的 综 合利 用打 下 了基 础。 相似文献
17.
Karstic aquifers are considered as the main sources of groundwater in the northeast of Rudbar, Iran. The present study was conducted to evaluate the hydrogeological properties of karstic springs in this region. For this purpose, saturation indices (SI values) were calculated using the geochemical PHREEQC model for a number of minerals in the groundwater in the karstic aquifer. Moreover, AqQA-RockWare software packages were used to prepare hydrogeochemical plots for the aquifer, using which the sources of the ions in the water were identified. The origin of bicarbonate, calcium, and magnesium ions in water was determined using chloro-alkaline indices. Moreover, through plotting a Piper diagram for spring water samples, it was discovered that water type of all springs is the Ca-HCO3 type, confirming the karstic characteristic of springs in the area. A Durov diagram also suggests that the water composition of the springs is of the bicarbonate type with the dominant Ca cation, suggesting the calcareous effects of the region on the quality of groundwater and exhibiting a single source for the springs. The calculated saturation indices show that most of the water samples are undersaturated with respect to calcite, dolomite, and CO2. The stable isotopes (δ18O and δ2H) and deuterium excess values were used to get information about transport pathways in groundwater, atmospheric moisture, and the degree of interaction between these reservoirs. The degree of karstification of the recharge area of the karst aquifer was determined to be 5.5 from an analysis of the hydrograph Sefidab Spring. 相似文献
18.
黔东北高原斜坡地区4种岩溶地下水系统模式及特点——基于地貌和蓄水构造特征 总被引：5，自引：0，他引：5
受深切河谷地貌控制,黔东北大部分地区岩溶地下水深埋且排泄于河谷岸边,以快速的管道裂隙流为主,给地下水资源勘探开发带来了极大的困难,局部地区受蓄水构造控制形成勘探有利的地下水富集区。笔者基于地貌和蓄水构造将研究区岩溶地下水系统归纳总结为深切河谷型、向斜山地型、单斜夹层型和背斜槽谷型4类模式。深切河谷型岩溶地下水系统地下水水力坡度大,地下水以快速的管道流为主,排泄点低,开发利用方式建议直接在地下河出口或天窗中抽提地下水,经济效益明显地区可堵洞成库进行综合利用;向斜山地型岩溶地下水系统发育高位岩溶泉或地下河出口,排泄点高,适合直接引水利用;单斜夹层型岩溶地下水系统在岩性接触带出露一系列接触泉,排泄分散,开发利用方式建议直接利用或抽提岩溶泉水,受夹层隔水顶底板影响局部地区可钻井取水;背斜核部出露寒武系白云岩地层,导致背斜槽谷型岩溶地下水系统含水岩层均匀厚度大,分布大量非全排型岩溶泉,地下水开发适合抽提泉水或钻井抽取地下水。 相似文献
19.
综合利用马坑矿区积累的水位、水温资料,结合前期对矿区水文地质条件的认识,查明了矿区岩溶水在疏干条件下的补给的变化特征。矿区岩溶含水层以石炭系船山组至二叠系栖霞组灰岩为主,大气降水为其主要补给来源。矿区开采过程中由于矿山采石场开采灰岩造成的溶洞出露地表、采空塌陷裂隙、第四系扰动及沟谷堵塞等使大气降水入渗补给量增大;断层破碎带使分布于灰岩含水层上部的二叠系文笔山组泥质砂岩地层具有了良好的含水性及导水性,致使其上部加福组砂岩裂隙水通过小娘坑断层及F3断层等破碎带补给岩溶水;溪马河河水沿河床与F1断层交汇段渗漏补给岩溶水;深部花岗岩低温热水也沿F1及F10断层破碎带进入矿坑。 相似文献
20.
Jacek Rózkowski 《Environmental Geology》1998,33(4):274-278
A karst-fissured aquifer in the Upper Jurassic carbonate rocks of the Krakow Upland shows a very high yield (safe yield 117 000 m3/day) and belongs to the major groundwater basins (MGBs) of Poland. The uncovered character of the aquifer and its hydraulic
structure favor the intensive infiltration and migration of anthropogenic pollutants from the surface. This pollution is caused
by agriculture and industry in the proximity of Krakow and the Upper Silesian agglomeration. Progressive degradation of groundwater
quality on a regional scale results. Evaluation of the endangering of the aquifer studied is based on the analysis of the
time interval of vertical water percolation from the surface, the time interval of groundwater horizontal flow through the
aquifer and the duration of water residence in the aquifer derived from tritium data. Quaternary and Cretaceous overburden
occur in the Krakow Upland in addition to numerous outcrops of limestones. The time interval of vertical water percolation
in highly permeable limestones does not exceed 3 years and in the areas covered by overburden it is from several to 50 years.
The mean effective time interval of horizontal groundwater flow through the Upper Jurassic rocks along the flow paths ranges
from several months in the areas of direct drainage to over 15 years in the elevated areas of local groundwater divides. The
age of water in the rock matrix was determined using tritium data interpreted according to an exponential model and it ranges
from 70 years to over 130 years. In karst-fissured systems with a high retardation index (Rp=21) the effective time of water circulation in local drainage basins does not exceed 7 years.
The Krakow-Wieluń Upland is the most extensive and uniform karst region in Poland. It is a belt of Upper Jurassic limestone
extending from Krakcow in the southeast to Wieluń in the northwest on the northeast slope of the Silesian Upland. Residual
hills of Paleogene age separated by infilled karst depressions are the most characteristic features of the Krakow-Wieluń Upland.
More than 800 small caves are known in this area, but only two of them reach 1 km of aggregate passage length (Gazek and others
1992).
Received: 4 December 1996 · Accepted: 29 April 1997 相似文献