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This study was carried out in the Cuenca de la Independencia, a semi-arid basin in Central Mexico. The objective is to describe the main features of a groundwater flow regime under natural conditions, based on groundwater discharge manifestations. Information obtained from paleoecological, paleontological, archaeological and historical data suggests that, prior to heavy development (starting in the 1950s), the hydrogeologic regime was characterized by a larger groundwater availability in a more humid and colder climate. Manifestations associated to groundwater discharges are springs, lagoons, wetlands, saline soils, chalcedony deposits, phreatophytes, thermalism, and artesianism. The different types of manifestations and their position in the basin indicate the influence of groundwater flow systems hierarchically nested, forming concentric zones at ground level. The groundwater flow regime corresponds to a classical gravity-induced flow system with generation of local, intermediate and regional patterns. Integrating several types of data to establish the flow geometry and its dynamics has proven a useful tool to increase understanding of the original groundwater regimes. This approach can also be applied in other over-exploited semi-arid basins. 相似文献
2.
Speleogenetic history of the Hungarian hydrothermal karst 总被引:2,自引:0,他引:2
Y. V. Dublyansky 《Environmental Geology》1995,25(1):24-35
The hydrothermal karst of Hungary displays at least two principal stages of development in two differing environments. Caves of an early stage were formed within a deep zone of low thermal gradient. These caves (vugs) are small (tens of centimeters) and lined with scalenohedral crystals of calcite that are often in association with barite. Calcite yields fluid inclusion temperatures of 55–95°C and is depleted in18O (–11.2 to –17.6 per mil PDB). The caves were formed by ascending thermal waters charged with CO2. Solubility of CaCO3 in such a system gradually increases with the ascent of the fluid (solutional zone) but drops sharply at a depth of –250 m to –500 m below the water surface (depositional zone). Caves formed in the solutional zone may be shifted into the depositional zone due to tectonic uplift, and calcite lines their walls. Large caves (tens to thousands of cubic meters) of a late stage were formed within a shallow zone of high thermal gradient immediately below and above the thermal water table. The calcite of the phreatic crusts has a rhombohedral habit, displays lower fluid inclusion temperatures (35–55°C and less), and a depletion in18O of –9.5 to –14.6 per mil PDB. Several powerful cave-forming processes may operate there including convection, mixing/cooling corrosion, and condensation corrosion. Due to differences in the rate of tectonic uplift, rate of hydrothermal system decay, and hydrogeologic pattern, these caves were either filled with water for a long period of time (phreatic calcite crusts are formed) or partly dewatered early in their history (waterline and subaerial speleothems are formed). The zones of thermal cave formation recognized in Hungary may have a universal character. Very similar features are found in other hydrothermal karst areas of the world (Kirghizia, Algeria, South Dakota). 相似文献
3.
成矿古水热系统与热液铀矿床研究历史,现状与展望 总被引:3,自引:0,他引:3
介绍了成矿古水热系统与热液铀矿床研究的历史与现状。指出了以往研究只强调水及溶质起源,而对热源重视不够的欠缺。同时,结合热液铀 矿床的研究情况,对成矿古水热系统研究的下一步发展方向进行了展望。 相似文献
4.
本文在对和丰-布尔津盆地构造-沉积演化史作简要分析之后,将盆地水文地质发展历史划分成若干水文地质旋回与阶段,然后恢复上、下第三系含水岩组的水文地质期发展演化史,总结出下第三系乌伦古河组找矿目的具备良好的古淋滤水动力条件。 相似文献
5.
Eliyahu Rosenthal Akiva Flexer Peter Möller 《International Journal of Earth Sciences》2006,95(4):725-740
One of the most important processes leading to the deterioration of groundwater in Israel is the migration of brines penetrating into fresh groundwater bodies. Such manifestations occur at an ever increasing frequency and in unexpected locations. The hydrochemistry of these processes reveals the possibility of involvement of several types of brines. The distribution and the hydrostratigraphic sequence of the brines is correlated with the evolution of paleoenvironments during the geological history of the region. Several major phases of brine and evaporite formation are discerned: The earliest phase occurred in the Paleozoic–Early Mesozoic (Yam Suf–Ramon–Lower Arad Groups) during which brines were generated by dissolution of evaporites. The second major phase in the evolution of brines occurred during the Mio-Pliocene. In the western areas of the country, the brines were generated mainly by the post-Messinian ingression of seawater which dissolved evaporites and reacted with the invaded rock sequence. In the Rift and in adjoining areas, the dominant brine was the final product of the evaporation of an inland marine lagoon (the Sdom Sea) which penetrated into an environment prevalently built of previously formed rocks and, particularly of clastic beds filling at that time, the nascent rift. From this evaporating lagoon precipitated evaporates, the dissolution of which produced brines. A further step in the hydrochemical evolution in the Rift was the creation of the Lisan Lake, which became progressively saline, probably as the result of dissolution and flushing of salts derived from the previous hypersaline Sdom Sea. The contemporary phase in the Rift is characterized by an ongoing process of flushing-out of residual brines and dissolution of evaporites by currently recharged fresh water. Throughout the geological history of the area, four major periods of flushing stand out. These occurred between the Triassic and the Jurassic, at the end of the Jurassic, as the result of the Oligocene uplift and as part of the Messinian event. As the result of these processes, the rock-sequences were flushed off previously formed brines and evaporites and were “made ready” for following generations of liquids. 相似文献
6.
Chemical evolution of saline waters in the Jordan-Dead Sea transform and in adjoining areas 总被引:1,自引:0,他引:1
Peter Möller Eliyahu Rosenthal Stefan Geyer Akiva Flexer 《International Journal of Earth Sciences》2007,96(3):593-597
The Ca–Mg relationship in groundwaters strongly points to the overall dolomitization and local albitization. The Mg/Ca ratios
reveal two trends by which saline waters develop: increase of Mg/Ca ratio by evaporation and decreasing Mg/Ca ratios due to
dolomitization and albitization. Br/Cl vs. Na/Cl ratios demonstrate that albitization does not play a major role which leaves
dolomitization to be the main source for decreasing Mg/Ca ratios in saline waters. In the eastern and southern Region of Lake
Kinneret, salinization occurs by mixing with a Ca/Mg molar ratio <1 brine (Ha’On type). Along the western shoreline of the
Lake, a Ca/Mg > 1 dominates, which developed by the albitization of plagioclase in abundant mafic volcanics and the dolomitization
of limestones. The most saline groundwater of the Tabgha-, Fuliya-, and Tiberias clusters could be regional derivatives of
at least two mother brines: in diluted form one is represented by Ha’On water, the other is a Na-rich brine of the Zemah type.
Additionally, a deep-seated Ca-dominant brine may ascend along the fractures on the western side of Lake Kinneret, which is
absent on the eastern side. Groundwaters of the Lower Jordan Valley are chemically different on both sides of the Jordan River,
indicating that the exchange of water is insignificant. All saline waters from the Dead Sea and its surroundings represent
a complex mixture of brines, and precipitation and local dissolution of halite and gypsum. Many wells of the Arava/Araba Valley
pump groundwater from the Upper Cretaceous limestone aquifer, the origin of the water is actually from the Lower Cretaceous
Kurnub Group sandstones. Groundwater drawn from the Quaternary alluvial fill either originates from Kurnub Group sandstones
(Eilat 108, Yaalon 117) or from altered limestones of the Judea Group. The origin of these waters is from floods flowing through
wadis incised into calcareous formations of the Judea Group. On the other hand, as a result of step-faulting, hydraulic contact
is locally established between the Kurnub- and the Judea Groups aquifers facilitating the inter-aquifer flow of the confined
Kurnub paleowater into the karstic formations of the Judea Group. Two periods of Neogene brine formation are considered: the
post-Messinan inland lagoon resulting in drying up of the Sdom Sea and the evaporation of the Pleistocene Samra Lake, which
went further through the stage of Lake Lisan to the present Dead Sea. For the first period, major element hydrochemistry suggests
that the saline waters and brines in the Jordan-Dead Sea–Arava Valley transform evolved from the gradual evaporation of an
accumulating mixture of sea-, ground-, and surface water. Due to the precipitation of carbonates, gypsum, and halite, such
an evaporating primary water body was strongly enriched in Mg, Br, and B and shows high molar ratios of Br/Cl, B/Cl, and Mg/Ca
but low Na/Cl ratios. The development of the Br/Cl ratio is chemically modelled, showing that indeed brine development is
explicable that way. Along with the evaporation brine, evaporites formed which are leached by infiltrating fresh water yielding
secondary brines with Na/Cl ratios of 1. When primary brines infiltrated the sub-surface, they were subjected to Mg–Ca exchange
in limestones (dolomitization) and to chloritization and albitization in basic igneous rocks turning them into Ca-Cl brines.
These tertiary brines are omnipresent in the Rift. The brines of the late Lisan and Dead Sea were generated by evaporating
drainage waters, which leached halite, gypsum, and carbonates from the soil and from the sub-surface. All these brines are
still being flushed out by meteoric water, resulting in saline groundwaters. This flushing is regionally enhanced by intensive
groundwater exploitation. In variable proportions, the Neogene and late Lisan Lake and Recent Dead Sea brines have to be considered
as the most serious sources of salinization of groundwaters in the Rift. Deep-seated pre-Sdom brines cannot strictly be excluded,
but if active they play a negligible role only.
An erratum to this article can be found at 相似文献
7.
Slovakia has many areas rich in thermal waters one of which is the Hornonitrianska kotlina depression. At four localities
three types of waters are found. The first belongs to the Ca–Mg–HCO3 type with T.D.S. 0.7 g/l, the second to the Ca–Mg–SO4 type with T.D.S. 1.37–2.01 g/l and the third to the Ca–Mg–SO4–HCO3 type with T.D.S. 0.97 g/l. Discharge at individual localities varies up to 30 l/s and temperatures of water reach 32.5–66.6 °C.
The waters are predominantly used for healing, rehabilitation purposes, recreation and heating.
Received: 8 March 1999 · Accepted: 7 June 1999 相似文献
8.
在分析华东南相山铀矿田成矿地质背景、古气候条件基础上,运用古水文地质分析方法研究铀成矿古水热系统的构造——古水文地质条件和古水动力条件。划分了两个古水文地质期和两个古水文地质区,确定了成矿古水热系统补给区、排泄区位置,并分析了水循环过程中铀的矿化形成过程。研究结果表明相山铀矿田的形成是由于大气降水在补给区渗入地下,经深循环加温和水岩相互作用形成的富铀成矿热液在古水热系统排泄区(减压区)沉淀富集成矿。 相似文献
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