解释湖成和海成沉积物磁性记录的一种简单模式     

Hilton  J  张志良 《国外第四纪地质》1989,(1):53-60

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微山湖区水文地质条件对湖下采煤的影响     

王永红  沈文 《煤田地质与勘探》1992,20(2):40-43

从构造、煤系及其盖层水文地质特征与湖水关系上,综合分析了微山湖区水文地质条件的南北差异,并论述了开采引起的覆岩破坏特征和对湖下采煤的影响。应用模糊数学方法,对湖区进行了安全开采的评价,指出了应注意的问题。  相似文献   

陆地古水文学研究进展     

L.Starkel 《第四纪研究》1992,12(2):144-144

尽管97％以上的水储存在海洋中,对大陆来说,水犹如血液循环一样重要,即使每年只有占世界水总量O.0009％的水作为降水落到大地。我们对古水文变化的了解主要来自无数分散的地质记录,以及全球尺度的古气候模型,并且这些模型的获得通常是以难以证实的假定为基础的。在古水文学研究中,我们试  相似文献   

大同-阳原盆地古泥河湾湖的岸线变化   总被引：8，自引：0，他引：8  

夏正楷 《地理研究》1992,11(2):52-59

本文通过大同-阳原盆地古湖岸线遗迹的分析,阐述第四纪古泥河湾湖的出现、发展和消亡,指出湖泊变迁是构造运动和气候变化等因素共同作用的结果,构造运动是主要因素。  相似文献   

柴达木红柳泉区     

关佐蜀 《地质论评》1949,14(Z1):70-70

位置新油田们于格孜库勒湖之东北隅,东北距敦煌四百余公里,东南去西宁约一千二百公里,西北去婼(女羌)约三百公里,汽车俱可通行。  相似文献   

河南汤阴地堑的地震地质特征与地震危险性   总被引：13，自引：1，他引：12       下载免费PDF全文

韩慕康  赵景珍 《地震地质》1980,2(4):47

本文论述太行山前地震构造带南段、汤阴地堑的新活动特点,发现只有其南部是地堑,北部是由一条东侧断裂构成的半地堑。而汤阴地堑西侧断裂为断距往北迅速减小以至消失的断层。作者在野外工作结束时曾预测汤阴县西部是由于捩点继续北移而可能发震的一个危险区,并为后来在该处发生的一个3.9级地震所证实。此外,安阳市一带因有一条活动强烈、断面分别倾向南、北的北西西向枢纽断层——安阳断裂横截于南部的汤阴地堑和北部的磁县、临漳诸断裂之间,是应力容易集中、有发震可能的另一危险区,应注意监测  相似文献   

基于GIS的福建省湖雷地区钼矿成矿预测     

王春女  韩振哲  陈建平 《地理信息世界》2016,(1):46-52

本文在总结该区区域成矿规律的基础上,基于GIS平台对地质、物探、化探数据进行了分析处理,分别提取出有利成矿的地质因素、航磁因素、化探异常,并利用航磁数据对该地区的断裂、岩体进行了推断,扩充了有利地质因素。在此基础上,建立了福建省湖雷地区钼矿成矿预测模型,通过Morpas软件进行了证据权计算,圈定了5个找矿远景区。  相似文献   

益阳大通湖生态因子的灰关联分析   总被引：1，自引：1，他引：0  

杨品红  徐黎明  覃忠元  潘莹  湛瑊  石彭灵  张倩  王晓艳  谢春华  李梦军 《海洋与湖沼》2016,47(5):1063-1067

本文采用灰色系统关联度分析方法,以空间理论数学为基础,依规范性、偶对称性、整体性和接近性原则,计算并分析了益阳大通湖14个生态因子的关联度,关联序结果为:亚硝酸氮氮磷比氨氮总氮硝酸氮浮游动物叶绿素a透明度总磷水深水温浮游植物酸碱度溶解氧。益阳大通湖表现为总氮(包括亚硝酸氮、氨氮和硝酸氮)和氮磷比是优势影响因子。通过灰关联分析发现,大通湖水体水质良好,水体的总氮、氮磷比及总磷都适于浮游生物的生长繁殖,对增加渔产潜力有重要作用。  相似文献   

The effects of microbial activity on the geochemistry of highly acidic crater lakes： An example from Laguna Caliente, Poas volcano （Costa Rica）     

Franco Tassi Orlando Vaselli Erik Fernandez Eliecer Duarte Giordano Montegrossi Angelo Minissale 《中国地球化学学报》2006,25(B08):228-229

Laguna Caliente is a crater lake hosted within the Poas volcano （Costa Rica） that is considered one of the most active volcanic systems of Central America. Laguna Caliente is characterized by extremely low pH （-1） and very high TDS values （up to 33700 mg/L）, although, in the last two decades, the lake volume has significantly changed, mainly in relation to variations of the fumarolic activity. In this work, we present the chemical and isotopic compositions of water and dissolved gases collected along the vertical profile of the lake in order to constrain the main processes that control its physical-chemical features. Water and gas samples were collected. Laguna Caliente has a Ca （Mg）-Cl （SO4） composition, typical of acid-brine lakes of active volcanic systems. Among dissolved gases, CO2 content, by considering the low pH, is particularly high （up to 18.1% by vol.）, and relevant amounts of oxygen （15.8. % by vol.）, preventing the formation of any anoxic hypolimnion, are also present at the maximum depth. Temperature and chemical species remain almost constant along the vertical profile, with the exception of F- that shows a moderate increase with depth and CI and SO4^2-, whose contents increase by more than 10% at the depth of 20 m, and, below 20 m, decrease to values similar to those measured at surface. This compositional stratification may be tentatively explained by the complex combination of, at least, three processes： （1） input of high-temperature volatiles from sub-lacustrine fumaroles, （2） loss of HCl and H2S from lake surface through evaporation, and （3） SO4^2- and CI consumption due to microbial activity at the bottom of the lake.  相似文献   

Catastrophic and persistent environmental consequences of an acid crater-lake discharge, Chiginagak Volcano, Alaska     

Janet R. Schaefer William C. Evans Bronwen Wang William E. Scott Robert G. McGimsey Janet Jorgenson 《中国地球化学学报》2006,25(B08):230-231

In early summer 2005, acidic, metal-laden water and clay-rich debris flooded down the flanks of the Chiginagak Volcano, Alaska. The estimated 3-million-m^3 discharge occurred during a rapid partial draining of a newly formed summit crater lake. Twenty-seven kilometers downstream from the source, Mother Goose Lake, a 500-million-m3 lake, was acidified from surface to bottom （pH ranged from 2.9 to 3.06）. All aquatic life was killed and salmon spawning runs were eliminated. The flood was accompanied by a simultaneous release of caustic volcanic gas and aerosols that followed the flood flow-path, and caused defoliation and necrotic leaf damage to vegetation in a 30-km^2 area along and above affected streams. In September 2005, approximately 1.4 million m^3 of acidic water remained and continued to drain from the summit crater lake. Water sampled 8 km downstream after considerable dilution from glacial meltwater was a weak sulfuric acid solution （pH-3, SO4^2- ～500 mg/L, and SO4^2-/Cl～10）. Cation proportions decreased in the order of Ca〉Fe〉Al〉Mg〉Na〉K. The eightfold predominance of Ca^2＋ over Mg^2＋ may reflect some dissolution of anhydrite, but only about 30% of the SO4^2- can be balanced by Ca^2＋. The anomalously high concentrations of Fe （-25 mg/L） and A1 （-18 mg/L） are derived from rock dissolution under the acidic conditions within the crater lake, and appear to be the most serious environmental threat in terms of metals. Further downstream, at stream and lake sites ranging from 8 to 40 km from the source, concentrations of cations remained high and hazardous metals such as As, Cr, and Cu were elevated well above background levels. Copper concentrations exceeded the U.S. Environmental Protection Agency＇s chronic exposure limit for aquatic life at most sampled sites and several sites exceeded the acute exposure limit.  相似文献