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1.
Origin and Distribution of Groundwater Chemical Fields of the Oilfield in the Songliao Basin, NE China 总被引：1，自引：0，他引：1
JIN Aimin LOU Zhanghu ZHU Rong CAI Xiyuan GAO Ruiqi Department of Water Conservancy Ocean Engineering Zhejiang University Hangzhou Zhejiang China Petrochemical Corporation Beijing Exploration Bureau CNPC Beijing 《《地质学报》英文版》2005,79(5):688-696
There are many factors affecting the chemical characteristics of groundwater in the forming process of groundwater chemical fields, such as freshening due to meteoric water leaching downwards, freshening due to mudstone compaction and water release, concentration due to infiltration and freshening due to dehydration of clay minerals. As a result, the groundwater chemical fields are characterized by lengthwise stages and planar selectivity. The former arouses vertical chemical zonality of groundwater. Five units could be identified downwards in the Songliao basin： （1） freshening zone due to downward-leaching meteoric water, （2） concentration zone due to evaporation near the ground surface, （3） freshening zone due to mudstone compaction and water release, and concentration zone due to compaction and infiltration, （4） freshening zone due to dehydration of clay minerals, and （5） filtration-concentration zone; whereas the latter determines the planar division of groundwater chemical fields： （1） the freshening area due to meteoric water, asymmetrically on the margin of the basin, （2） the freshening area due to mudstone compaction and water release in the central part of the basin, （3） the leaky area, which is a transitional zone, and （4） leakage-evaporation area, which is a concentration zone. In the direction of centrifugal flows caused by mudstone compaction in the depression area, the mineralization degree, concentrations of Na^＋ and Cl^-, and salinity coefficient （SC） increase, while concentrations of （CO3^2- ＋HCO3^-） and SO4^2-, metamorphism coefficient （MC） and desulfuration coefficient （DSC） decrease. However, all these parameters increase in the direction of gravity-induced centripetal flows. 相似文献
2.
Yunchao LANG Congqiang LIU Jianghong WU Hiroshi Satake Siliang LI 《中国地球化学学报》2006,25(B08):173-173
A groundwater system in a karstic terrain is easily subject to pollution and its remediation is difficult once contaminated by human activities. The groundwater samples collected in both winter and summer seasons at Guiyang, SW China, show a wide range of variations in chemical composition and dominance of Ca^2＋, Mg^2＋, SO4^2-, and HCO3^- ions. The anthropogenic inputs include Cl^-, NO3^-, SO4^2-, Na^＋, and K^＋, as judged from the relationships between different elemental ratios and sewage samples. Cl^- concentrations of all water samples in the study area vary from 0 to 3.9 mmol/L in winter and are higher than in summer. In most of the samples, SO4^2- concentrations are high, ranging from 0.1 to 11 mmol/U The studies show that the cycling of sulfur plays an important role in controlling water chemistry and fate of contaminants in groundwater. In order to understand the source of SO4^2- and the geochemical cycling of some elements in the karstic groundwater environment, we have carried out a study on the variations of S and Cl isotope compositions, in addition to other isotopic tracers such as ^87Sr/^86Sr and δ^13C studied previously. The δ^37Cl values of the groundwater samples present a seasonal variation, ranging from 0.00‰ to ＋2.03‰ in winter and from -1.46‰ to ＋0.29‰ in summer. The surface water samples show a similar range of variations as observed for groundwater. Two rainwater samples collected at Guiyang have a distinct isotopic signature （mean value is -3‰） compared to the δ^37Cl values reported in literature. These results indicate that ground water is mainly derived from precipitation and suggest a fast recharge of the karst system by surface water. 相似文献
3.
It is necessary to understand the aquatic chemical characterstics of natural surface fresh water for water quality assessment.The chemical data from different kinds of water in the central Guizhou karst area showd that spring water from carbonate rock cracks(crack-water)is of neutrality or meta-alkalinity and [C] Ca II type.The amounts of all ions and the concentrations of HCO3^- and Ca^2 were higher in the autumn than in the spring,The crack-water was influenced by the infiltration of surface water in the process of erosion and /or trans-portation with decreasing HCO3 and increasing pH,SO4^2-,Cl^-,K^ and Na^ during running in a certain distance on the land surface .In particular,the chemical compositions of the waters at Tianxingqiao(upper-stream),Shuiliandong(mid-waterfall)and Luoshuitan(down-pool)near the Huangguoshu Waterfall were much different from those of the crack-water.The concentration of SO4^2-,Na^ ,Fe^3 and NO3^- varied closely with seasons.The CaCO3 deposited violently with CO2 release in the spring ,In Lake Hongfeng the HCO3^-/SO4^2- equivalent ratios were only 2.1-2.4 ,but Ca^2 /Mg^2 up to 2.4-4.2.The Cl^- concentration increased by a factor of 1 and Na^ by order of magnitude relative to the spring water.These indicated the increase in artificial pollutant discharge in the Lake Hongfeng watershed.In addition,Proewater in the soils covering carbonate rocks belongs to strongly mineralized water,The obvious differences in water quality were controlled by carbonate deposition,sulphate mineralization and nitrogen fixation as well as ammonification.It is indicated thaty the chemical compositions in the waters from the karst region were unstable and changeable. 相似文献
4.
The present study investigates the hydrogeochemical characteristics of groundwater quality in Agas- theeswaram taluk of Kanyakumari district, Tamil Nadu, India. A total of 69 groundwater samples were collected during pre- and post-monsoon periods of 2011-2012. The groundwater quality assessment has been carried out by evaluating the physicochemical parameters such as pH, EC, TDS, HCO3, Cl, SO42-, Ca2＋, Mg2＋, Na＋ and K＋ for both the seasons. Based on these parameters, groundwater has been assessed in favor of its suitability for drinking and irrigation purpose. Dominant cations for both the seasons are in the order of Na＋〉 Ca2＋〉 Mg2＋ 〉 K＋ while the dominant anions for post monsoon and pre monsoon have the trends of CI 〉 HCO3 〉 SO42- and HCO3- 〉 CI 〉 SO42-, respectively. Analytical results observed from various indices reveal that the groundwater quality is fairly good in some places. Analytical results of few samples show that they are severely polluted and incidentally found to be near the coasts, estuaries and salt pans in the study area. The Gibbs plot indicates that the majority of groundwater samples fall in rock dominant region, which indicates rock water interaction in the study area. The United States salinity （USSL） diagram shows that the groundwater is free from sodium hazards but the salinity hazard varies from low to very high throughout the study area. This reveals that the groundwater is moderately suitable for agricultural activities. The observed chemical variations in pre-monsoon and post-monsoon seasons may be the effect to rock-water interactions, ion-exchange reactions, and runoff of fertilizers from the surrounding agricultural lands. 相似文献
5.
QIAN Jianping LI Shuangli CAO Chao 《中国地球化学学报》2008,27(1):82-89
Through a systematic observation of water level and temperature, and a comprehensive analysis of the data on major/trace elements, nitrite, hydrogen-oxygen isotopes, the conclusion has been drawn that there are two relatively independent groundwater systems （cool water and hot water）, and the geochemical indicators of hot/cool waters are described. The cool water system is relatively enriched in Ca^2＋, Mg^2＋ and HCO3^-. Its TDS is relatively low, about 1400-1800 mg/L. The hot water system is relatively enriched in K^＋, Na^＋, Cl^- and SO4^2-. Its TDS is relatively high, about 2200-2300 mg/L. The cool water system is enriched in Ba, Ga, Cd, and the hot water system is enriched in B, Ti, Cr, Ni, Cu, Mo, Rb, and Cs, relatively. Especially, the contents of Rb and Cs in the hot water system are more than five times as high as those in the cool water system. The NO3^- contents of cool water discharged from the gold mine are relatively high, and those of hot water are extremely low. The 8D and 8-80 values follow an increasing order of surface water〉mine cool water〉mine hot water. The cool water comes mainly from the lateral supply of phreatic water, while the hot water comes mainly from the vertical supply of deeply circulating structure-fracture water. The ratio of cool water over hot water was estimated to be about 1：1 by a water quality model.. 相似文献
6.
The average temperature of Thailand is projected to increase by 2-3 °C, and the annual rainfall is projected to increase by 25% and up to 50% in certain areas. The climate change in future is expected to provide changes in hydrological cycle and therefore impacts the groundwater resources too. In this study, we analyzed the general climate change trends and reviewed the groundwater conditions of Thailand. The climate changes, hydrologic variability and the impact of climate change on groundwater sustainability are also discussed based on a national groundwater monitoring program. Currently, there are 864 groundwater monitoring stations and 1 524 monitoring wells installed in Thailand. Moreover, the impact of climate change on groundwater-dependent systems and sectors is also discussed according to certain case studies, such as saline water intrusion in coastal and inland areas. Managing aquifer recharge and other projects are examples of groundwater adaptation project for the future. 相似文献
7.
《中国地球化学学报》2006,(Z1)
The Sipadan island is the only oceanic island found in Malaysia, and is popularly known for its beautiful corals and diving activities. The aquifer of the island is affected by seawater intrusion associated with groundwater exploitation. Geologically, the… 相似文献
8.
Alleppey is one of the thickly populated coastal towns of the Kerala state in southern India.Groundwater is the main source of drinking water for the 240,991 people living in this region.The groundwater is being extracted from a multi-layer aquifer system of unconsolidated to semi-consolidated sedimentary formations,which range in age from Recent to Tertiary.The public water distribution system uses dug and tube wells.Though there were reports on fluoride contamination,this study reports for the first time excess fluoride and excess salinity in the drinking water of the region.The quality parameters,like Electrical Conductivity(EC) ranges from 266 to 3900 μs/cm,the fluoride content ranges from 0.68 to2.88 mg/L,and the chloride ranges between the 5.7 to 1253 mg/L.The main water types are Na-HC03,NaCO_3 and Na-Cl.The aqueous concentrations of F~- and CO_3~(2-) show positive correlation whereas F~- and Ca~(2+) show negative correlation.The source of fluoride in the groundwater could be from dissolution of fluorapatite,which is a common mineral in the Tertiary sediments of the area.Long residence time,sediment-groundwater interaction and facies changes(Ca-HCO_3 to Na-HCO_3) during groundwater flow regime are the major factors responsible for the high fluoride content in the groundwater of the area.High strontium content and high EC in some of the wells indicate saline water intrusion that could be due to the excess pumping from the deeper aquifers of the area.The water quality index computation has revealed that 62%of groundwater belongs to poor quality and is not suitable for domestic purposes as per BIS and WHO standards.Since the groundwater is the only source of drinking water in the area,proper treatment strategies and regulating the groundwater extraction are required as the quality deterioration poses serious threat to human health. 相似文献
9.
Xun ZHOU Rui LI Hua ZHANG Li ZHANG 《中国地球化学学报》2006,25(B08):228-228
Groundwater with low total dissolved solids （less than 200 mg/L） occurs in the unconfined and confined aquifers near Beihai in southern Guangxi, China. Under natural conditions the groundwater ranges in pH from 3,33 to 7,0 with an average value of 5.12. The pH in the unconfined aquifer varies from 3.67 to 7.0 with an average value of 5.17 and the pH in the confined aquifer is in the range 3.33-6.97 with an average value of 5.07. The pH in the groundwater does not show significantly increasing or decreasing trends with time. Fluctuations in pH exist at some of the monitoring wells and the pH in groundwater is a bit higher in the rainy season than in the dry season, Monitoring data show that the pH in rainwater is higher than in groundwater in the unconfined aquifer, whereas the pH in the latter is a bit higher than in the confined aquifer. A slightly decreasing trend in the pH was also found from the inland area to the coastal zone. The occurrence of weakly acidic groundwater in this area is attributed to the recharge from low pH precipitation and the multi-aquifer and leaky groundwater system. 相似文献
10.
Wei ZHANG Congqiang LIU Zhiqi ZHAO 《中国地球化学学报》2006,25(B08):172-172
Boron has two stable isotopes （^10B and ^11B） with relative abundances of about 20% and 80%, respectively. Boron isotopic ratios in natural materials show a huge range of variations, from -70‰ to ＋60‰, when expressed with the classical δ^11B notation. Most of these isotopic variations occur at the surface of the Earth. Hence, boron isotopic composition can be used as a sensitive tracer in geochemical study, for instance, to identify the different sources of contamination and factors controlling the salinity of groundwater. During the last decade, boron isotopes have been used to discriminate between the influences of seawater intrusion and anthropogenic discharge. But few of those researches can precisely identify the different sources of contamination. We measured the boron concentrations and boron isotopic ratios of groundwater samples collected in Guiyang City, as well as the major ions. The results indicate that the major ion composition of the groundwater in the investigated area is mainly controlled by the interactions between water and the dominant rock i.e. carbonates. All the water compositions are characterized by high concentrations of Ca^2＋, Mg^2＋, HCO3^-, SO4^2-, and NO3^-, which are the dominant contaminants. Both dissolved boron concentrations and isotopic ratios show large variations among the ground waters, from 2 μg/L to 90 μg/L and from -6‰ to ＋26‰, respectively. The boron concentrations and isotopic ratios indicate that the river across the studied city has been seriously contaminated by urban discharge. Boron concentrations of fiver water samples varied from 20 μg/L to 140 μg/L, with an average δ^11B value of ＋2.0‰. Using boron isotopic compositions and different geochemical indices allowed us to clearly identify and distinguish the two major sources of contamination, agricultural activity and urban wastewater. Both of the two sources are characterized by high boron concentrations but their boron isotopic compositions significantly differ. 相似文献
11.
Emily Keeble David I. Whiteside Michael J. Benton 《Proceedings of the Geologists' Association. Geologists' Association》2018,129(2):99-119
Pant-y-ffynnon Quarry in South Wales yielded a rich cache of fossils in the early 1950s, including articulated specimens of new species (the small sauropodomorph dinosaur Pantydraco caducus and the crocodylomorph Terrestrisuchus gracilis), but no substantial study of the wider fauna of the Pant-y-ffynnon fissure systems has been published. Here, our overview of existing specimens, a few described but mostly undescribed, as well as freshly processed material, provides a comprehensive picture of the Pant-y-ffynnon palaeo-island of the Late Triassic. This was an island with a relatively impoverished fauna dominated by small clevosaurs (rhynchocephalians), including a new species, Clevosaurus cambrica, described here from a partially articulated specimen and isolated bones. The new species has a dental morphology that is intermediate between the Late Triassic Clevosaurus hudsoni, from Cromhall Quarry to the east, and the younger C. convallis from Pant Quarry to the west, suggesting adaptive radiation of clevosaurs in the palaeo-archipelago. The larger reptiles on the palaeo-island do not exceed 1.5?m in length, including a small carnivorous crocodylomorph, Terrestrisuchus, and a possible example of insular dwarfism in the basal dinosaur Pantydraco. 相似文献
12.
Gilles Serge Odin 《Comptes Rendus Geoscience》2002,334(6):409-414
Lithostratigraphy, physicochemical stratigraphy, biostratigraphy, and geochronology of the 77–70 Ma old series bracketing the Campanian–Maastrichtian boundary have been investigated by 70 experts. For the first time, direct relationships between macro- and microfossils have been established, as well as direct and indirect relationships between chemo-physical and biostratigraphical tools. A combination of criteria for selecting the boundary level, duration estimates, uncertainties on durations and on the location of biohorizons have been considered; new chronostratigraphic units are proposed. The geological site at Tercis is accepted by the Commission on Stratigraphy as the international reference for the stratigraphy of the studied interval. To cite this article: G.S. Odin, C. R. Geoscience 334 (2002) 409–414. 相似文献
13.
The effect of water on accessory phase solubility in subaluminous and peralkaline granitic melts 总被引：4，自引：0，他引：4
The solubilities of columbite, tantalite, wolframite, rutile, zircon and hafnon were determined as a function of the water contents in peralkaline and subaluminous granite melts. All experiments were conducted at 1035 °C and 2 kbar and the water contents of the melts ranged from nominally dry to approximately 6 wt.% H2O. Accessory phase solubilities are not affected by the water content of the peralkaline melt. By contrast, solubilities are affected by the water content of the subaluminous melt, where the solubilities of all the accessory phases examined increase with the water content of the melt, up to 2 wt.% H2O. At higher water contents, solubilities are nearly constant. It can be concluded that water is not an important control of accessory phase solubility, although the water content will affect diffusivities of components in the melt, thus whether or not accessory phases will be present as restite material. The solubility behaviour in the subaluminous and peralkaline melts supports previous spectroscopic studies, which have observed differences in the coordination of high field strength elements in dry vs. wet subaluminous granitic glasses, but not for peralkaline granitic glasses. Lastly, the fact that wolframite solubility increases with increasing water content in the subaluminous melt suggests that tungsten dissolved as a hexavalent species. 相似文献
14.
Emmanuel Skourtsos Daniel Vachard Alexandra Zambetakis-Lekkas Rossana Martini Louisette Zaninetti 《Comptes Rendus Geoscience》2002,334(12):925-931
Some olistolites reworked in a Tertiary flysch of Mount Parnon (Peloponnesus, Greece) exhibit a Late Permian assemblage, dominated by Paradunbarula (Shindella) shindensis, Hemigordiopsis cf. luquensis and Colaniella aff. minima. This association corresponds to the Late Wuchiapingian (=Late Dzhulfian), a substage whose algae and foraminifera are generally little known. Contemporaneous limestones crop out in the middle part of the Episkopi Formation in Hydra, but they are rather commonly reworked in Mesozoic and Cainozoic sequences. The palaeobiogeographical affinities shared by the foraminiferal markers of Greece, southeastern Pamir, and southern China, are very strong (up to the specific level), and are congruent with the Pangea B reconstructions. To cite this article: E. Skourtsos et al., C. R. Geoscience 334 (2002) 925–931. 相似文献
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正20141596 Liu Yunhuan(School of Earth Sciences and Resources,Chang’an University,Xi’an 710054,China);Shao Tiequan Early Cambrian Quadrapyrgites Fossils of Xixiang Boita in Southern Shaanxi Province(Journal of Earth Sciences and Environment,ISSN1672-6561,CN61-1423/P,35(3),2013,p.39-43,3 illus.,20 refs.) 相似文献
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正20141719 Chen Zhijun(State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences,Wuhan 430074,China);Chen Jianguo Automated Batch Mapping Solution for Serial Maps:A Case Study of Exploration Geochemistry Maps(Journal of Geology,ISSN1674-3636,CN32-1796/P,37(3),2013,p.456-464,2 illus.,2 tables,10 refs.) 相似文献
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正20140962 Chen Fenning(Xi’an Institute of Geology and Mineral Resources,Xi’an710054,China);Chen Ruiming Late Miocene-Early Pleistocene Ostracoda Fauna of Gyirong Basin,Southern Tibet(Acta Geologica Sinica,ISSN0001-5717,CN11-1951/P,87(6),2013,p.872-886,6illus.,56refs.) 相似文献
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正1.IGNEOUS PETROLOGY20142008Cai Jinhui(Wuhan Center,China Geological Survey,Wuhan 430205,China);Liu Wei Zircon U-Pb Geochronology and Mineralization Significance of Granodiorites from Fuzichong Pb-Zn Deposit,Guangxi,South China(Geology and Mineral Resources of South China,ISSN1007-3701,CN42-1417/P,29(4),2013,p.271-281,7illus., 相似文献
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正20141205Cheng Weiming(State Key Laboratory of Resources and Environmental Information System,Institute of Geographic Sciences and Natural Resources Research,CAS,Beijing 100101,China);Xia Yao Regional Hazard Assessment of Disaster Environment for Debris Flows:Taking Jundu Mountain,Beijing as an 相似文献