海原盆地地下水咸化特征和控制因素   总被引：1，自引：0，他引：1       下载免费PDF全文

王雨山  李戍  李海学  程旭学  刘伟坡  张梦南 《水文地质工程地质》2019,(4):10-17

地下水是海原盆地唯一的供水水源,近年来部分地区地下水溶解性总固体(TDS)增高,引起了有关部门和水文地质工作者的高度关注。通过分析69组地下水样品的水化学和氢氧稳定同位素数据,对地下水补给来源和咸化的水文地球化学过程进行了研究。结果表明:地下水TDS值198.2~6 436.4 mg/L,沿着地下水流向,咸化程度增加,水化学类型从基岩区的HCO3—Ca·Mg型演化至滞留—排泄区的SO4·Cl—Na·Mg型。地下水补给来源主要为大气降雨和基岩裂隙水侧向径流,补给源—对地下水咸化贡献较小。溶滤作用具空间差异,基岩区和补给区以碳酸盐、硅酸盐风化为主,径流区和滞留—排泄区则为蒸发岩风化,硫酸盐是地下水中阳离子的主要来源。补给水、溶滤和蒸发对第四系地下水TDS的贡献比率分别为4.8%~81.2%、11.9% ~85.9%、1.7%~29.5%,溶滤作用是控制海原盆地地下水咸化的首要因素。当地有关部门应加大对基岩泉水的综合利用,同时注意控制海原县和西安镇等地区地下水开采量,防止地下水进一步咸化。另外,在微咸水分布区可引进地下水去除硫酸盐技术,提高微咸水利用程度。  相似文献   

微测井时深关系质量控制方法研究     

王克非  舒玉涵  姚茂敏  郑超  冀冬生  张萍  薛为平 《新疆地质》2019,(3):414-418

微测井是目前公认的精度最高的表层调查方法,其主要作用是宏观下的质控建模及静校正各方法应用精度的量化检验。在野外施工时,往往会遇到如电缆堆积等问题,使微测井的时深关系出现异常点,影响表层建模精度。本方法在不改变原微测井观测方式基础上,增加中远偏移距接收点记录,依据井中激发点之间的旅行时初至时差关系,准确判定出波阻抗界面位置,保证了微测井采集的可靠性。此方法在准噶尔盆地不同表层介质条件下进行测试和应用,均获得良好效果。  相似文献   

A Reconsideration of the Relationship between Conotubus and Cloudina in Southern Shaanxi: New Evidence from Geometric Morphometry     

LUO Jingzhou  LIU Ziwei  REN Jinjie  ZHAO Wenyu  CHAI Shu  CUI Zaihang  DAI Qiaokun  HUA Hong 《《地质学报》英文版》2019,93(Z2):269-270

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Numerical Modeling of the Relationship Between Mechanical Properties of Granite and Microparameters of the Flat-Joint Model Considering Particle Size Distribution     

Shu  Biao  Liang  Ming  Zhang  Shaohe  Dick  Jeffrey 《Mathematical Geosciences》2019,51(3):319-336

Mathematical Geosciences - Deep geothermal energy is typically stored in granite reservoirs, and natural granite is highly heterogeneous because it is composed of different sizes and shapes of...  相似文献   

The petrology of a complex sodic and sodic–calcic amphibole association and its implications for the metasomatic processes in the jadeitite area in northwestern Myanmar,formerly Burma     

Guang-Hai?Shi  Wen-Yuan?Cui  Peter?TropperEmail author  Chang-Qiu?Wang  Gui-Ming?Shu  Haixa?Yu 《Contributions to Mineralogy and Petrology》2003,145(3):355-376

In the Myanmar jadeitite area of Pharkan, amphibole felses occur between jadeitites and serpentinized dunites. These so-called amphibole fels boundary zones were studied optically and by electron microprobe, and found to include the six amphibole species magnesiokatophorite (Mg-kat), nyböite (Nyb), eckermannite (Eck), glaucophane (Gln), richterite (Rich) and winchite (Win). In most samples, the two main amphibole species Mg-kat and Eck coexist with amphiboles containing variable amounts of components of the remaining four species, as well as with the clinopyroxenes jadeite (Jd), omphacite (Omp) and kosmochlor (Ko). However, Mg-kat, Nyb and Eck are also present as separate phases as well as in zoned porphyroblasts with Mg-kat in the core, Nyb in the inner rims, and Eck in the outer rims. The analytical data on such zoned amphiboles reveal that the chemistry changes from core to inner rim by virtue of the substitution NaAlCa _-1Mg _-1 (glaucophane vector), and from the inner to the outer rim along MgSiAl _-1Al _-1 (tschermak vector). The overall substitution from core to outer rim is, therefore, along NaSiCa _-1Al _-1 (plagioclase vector). Based on the Si content, three groups can be distinguished within Eck: Eck coexisting with Nyb has low Si contents of <7.6 a.p.f.u., Eck rimming Nyb has higher Si contents of 7.6–8.0 a.p.f.u., and fine-grained Eck in the matrix has Si contents of 7.9–8.0 a.p.f.u. Plotting the amphibole analyses in a compositional volume with the axes (Na+K) in A, Na in M(4), and tetrahedral Si shows that three groups of amphibole compositions can be distinguished, one being subdivided into three subsets. Group A contains Rich and Mg-kat, B comprises of Win and Gln, whereas the subsets C can be defined as follows: C1: high-Na amphiboles with low tetrahedral Si; these are mainly amphiboles from the Eck field but overlap with the two fields of Gln and Win; C2: high-Na and low-Si Ecks overlapping to high-Si Nybs; this group is midway between Eck and Nyb end members; C3: high-Na Mg-kats. Textural observations indicate three stages of sodic and sodic–calcic amphibole growth: stage 1 are amphiboles of group A (Mg-kat+Rich), stage 2 are amphiboles of group C2 (Nyb+Eck with Si<7.6 a.p.f.u.), and stage 3 are amphiboles of groups C1 and B (Eck with Si>7.6 a.p.f.u., +Gln+Win). Based on the subdivision into the compositional groups A–C, the only hint to a miscibility gap is provided by the large gap in the (Na+K) content on the A site which may point to a possible solvus in the system Eck–Win. Overall, the amphiboles investigated here show discontinuities in their growth compositions, rather than miscibility gaps. Textural observations suggest amphibole formation during fluid infiltration in the contact zone between the jadeitite bodies and the surrounding peridotite under high-pressure conditions (>1.0 GPa) and rather low temperatures of about 250–370 °C. Based on compositional trends within the amphiboles as well as phase-equilibrium constraints between amphibole and coexisting pyroxene solid solutions, the chemical composition of zoned amphibole porphyroblasts indicates two growth episodes—increasing pressures from stage 1 to stage 2 lead to the formation of Nyb from Mg-kat, and subsequently decreasing pressures lead to the formation of stage 3 Eck from Rich.  相似文献   

黄河三角洲土地持续利用优化分析   总被引：9，自引：0，他引：9  

何书金  李秀彬  朱会义  苏光全 《地理科学进展》2001,20(4):313-323

在黄河三角洲主体东营市土地利用现状和变化特征分析的基础上 ,提出了因地制宜、发挥优势、突出综合效益和保护生态环境的土地持续利用优化原则与目标 ;按土地利用类型进行了土地持续利用约束分析 ;提出了退耕还林还牧、提高森林覆盖率 ,适当集中布局农村居民点、加大土地整理力度 ,适度开发滩涂地、荒草地和盐碱地等土地持续利用结构优化配置方案。  相似文献   

合理开发利用新疆水资源发展绿洲生态农业   总被引：12，自引：4，他引：12  

何文勤  章曙明 《干旱区地理》2001,24(1):42-46

通过对新疆水资源开发利用有关的重大生态环境问题以及农用水资源开发利用中存在的问题的分析，对绿洲生态农业在新疆的发展提出了具可行性的对策和建议。  相似文献   

人类活动地全球碳循环的影响   总被引：11，自引：0，他引：11  

郑淑颖  管东生 《热带地理》2001,21(4):369-373

工业革命前，碳循环是碳在大气、海洋和陆地生态系统间的流动。工业革命以来，化石燃料的使用使贮存于地质碳库中的碳参与短期碳循环，因森林和草原开垦等土地利用增加的CO2排放量加重了大气的负担；另一方面造林和再造林形成CO2汇。大气CO2增加导致的气候变化反馈过程影响碳循环。文中提出从控制人类活动入手平衡全球碳循环的收支。  相似文献   

福建近41年气候变化对自然植被净第一性生产力的影响   总被引：13，自引：2，他引：13  

闫淑君  洪伟  吴承祯  毕晓丽 《山地学报》2001,19(6):522-526

从福建建瓯、尤溪、南靖三区近41年自然植被净第一性生产力(NPP)的时空变化,讨论了全球气候变化对三区自然植被NPP的影响.结果表明三区近41年NPP平均为18 t/hm2.  相似文献   

胶东西北部断裂构造与成矿作用研究   总被引：10，自引：8，他引：10  

邓军  徐守礼 《现代地质》1996,10(4):502-511

以控矿断裂构造因素为主线，探讨分析断裂构造与含矿流体生成、运移、分配、聚集机制的关系，建立起断裂构造、围岩蚀变及矿化分带的对应关系，强调指出矿化类型及矿化组合分布以水平为主的空间分带特征。从构造地球化学角度，对断裂构造活动与地球化学行为在时空联系上进行了解析，加深了对区域构造控矿规律的认识  相似文献