鄂尔多斯盆地东胜砂岩型铀矿中铀矿物的电子显微镜研究

鄂尔多斯盆地东胜铀矿是我国一个重要的大型砂岩型铀矿床。通过电子显微技术,对该铀矿床中铀矿物的种类、产出特征进行详细的研究。研究确定东胜砂岩型铀矿床中铀矿物主要为铀石和水硅铀矿,两者紧密共生,它们均为表生铀矿物。铀矿物的颗粒十分细小,一般粒度均为微米级。铀石和水硅铀矿往往呈板状、不规则微粒状产出,铀矿物的表面溶蚀现象明显,有的还具纳米级的溶蚀孔。铀矿物的产出与蚀变黑云母、蚀变黄铁矿密切相关,也见到微脉状铀矿物集合体穿切碎屑石英等现象。研究表明在表生作用下,该铀矿床中的铀元素存在溶解(迁移)-沉淀(富集)的反复过程。     

Mineral Geochemical Compositions of Tourmalines and Their Significance in the Gejiu Tin Polymetallic Deposits, Yunnan, China

Abstract: The Gejiu tin polymetallic deposits are located in the southeastern part of Yunnan Province in China. A detailed electronic microprobe study has been carried out to document geochemical compositions of tourmalines from the deposits. The results indicate a systematic change of mineral geochemical compositions, which might be used as a mineral geochemical tracer for post-magmatic hydrothermal fluid, basin fluid and their mixture. The tourmalines from granite are schorl with Fe/(Fe+Mg) ratios of 0.912-1.00 and Na/(Na+Ca) ratios of 0.892-0.981. Tourmalines as an inclusion in quartz from the ore bodies are dravite with Fe/(Fe+Mg) ratios of 0.212-0.519 and Na/ (Na+Ca) ratios of 0.786-0.997. Tourmalines from the country rocks are dravite with Fe/(Fe+Mg) ratios of 0.313-0.337 and Na/(Na+Ca) ratio of 0.599-0.723. Tourmalines from cassiterite-tourmaline veins that occur in crannies within the country rocks show distinct optical zoning with alternate occurrence of dravite and schorl, Fe/(Fe+Mg)=0.374-0.843, Na/(Na+Ca)=0.538-0.987. It suggests that schorl in granite and dravite in carbonatite are related to magmatic fluid and basin fluid respectively. When magmatic fluid rose up and entered into crannies of the country rocks, consisting mainly of carbonatite, basin fluid would be constantly added to the magmatic fluid. The two types of fluid were mixed in structural crannies of the sedimentary basin accompanied with periodic geochemical oscillations to form material records in chemical composition zonings of tourmalines.     

Phase Chemistry Study of the Zabuye Salt Lake Brine: Isothermal Evaporation at 15°C and 25°C

Zabuye Salt Lake in Tibet, China is a carbonate-type salt lake, which has some unique characteristics that make it different from other types of salt lakes. The lake is at the latter period in its evolution and contains liquid and solid resources. Its brine is rich in Li, B, K and other useful minor elements that are of great economic value. We studied the concentration behavior of these elements and the crystallization paths of salts during isothermal evaporation of brine at 15°C and 25°C. The crystallization sequence of the primary salts from the brine at 25°C is halite (NaCl) → aphthitalite (3K2SO4·Na2SO4) → zabuyelite (Li2CO3)→ trona (Na2CO3·NaHCO3·2H2O) → thermonatrite (Na2CO3·H2O) → sylvite (KCl), while the sequence is halite (NaCl) → sylvite (KCl) → trona (Na2CO3·NaHCO3·2H2O) → zabuyelite (Li2CO3) → thermonatrite (Na2CO3·H2O) → aphthitalite (3K2SO4·Na2SO4) at 15°C. They are in accordance with the metastable phase diagram of the Na+, K+-Cl?, CO32?, SO42?-H2O quinary system at 25°C, except for Na2CO3·7H2O which is replaced by trona and thermonatrite. In the 25°C experiment, zabuyelite (Li2CO3) was precipitated in the early stage because Li2CO3 is supersaturated in the brine at 25°C, in contrast with that at 15°C, it precipitated in the later stage. Potash was precipitated in the middle and late stages in both experiments, while boron was concentrated in the early and middle stages and precipitated in the late stage.     

深穿透化探方法及在矿产勘查中的应用

文章简述了深穿透化探方法的基本理论,介绍了地气测量方法、活动态金属离子法、金属元素活动态提取法和电地球化学法4种深穿透化探方法,并对深穿透化探方法的应用现状及其地质效能进行了评析,指出在应用综合勘查技术和化探异常信息时需要注意与工作区的成矿地质条件相结合。     

磐石市矿业权实地核查测量技术总结

本文通过对磐石市矿业权实地核查测量工作的总结,对矿业权实地核查中测量技术的方法进行了全面介绍和系统阐述,为矿业权核查的顺利进行提供了良好的理论支持,同时也为今后类似测绘项目提供了宝贵的实践经验。     

广西兴业县龙安高岭土矿床成矿地质特征、选矿试验及开采价值浅谈

广西兴业县龙安高岭土矿床产于大容山花岗岩体龙门单元补充侵入岩,成矿母岩为细粒斑状二长花岗岩。高岭土分布广,储量大,埋藏浅,易开采,矿物组分主要为高岭石和石英。高岭石为片状晶体,有序度高,粒度细,粒级分布理想,广泛用于陶瓷、造纸、橡胶、油漆及无线电电子元件、冶金、石油、原子能、建材等,具有巨大的经济开采价值及广阔的市场需求前景。     

新疆冰川近期变化及其对水资源的影响研究

新疆的冰川水资源居全国第一,在新疆水资源构成和河川径流调节方面占有重要地位。最近30多年来,随着气温升高,冰川出现了剧烈的消融退缩,冰川融水径流量普遍增加,并对气温的依赖性增强。文章基于最新冰川观测研究资料,阐述新疆冰川的近期变化,分析对水资源的影响。研究表明,所研究的1800条冰川,在过去26～44年间,总面积缩小了11.7％,平均每条冰川缩小0.243km2,末端退缩速率5.8m/a。冰川在不同区域的缩小比率为8.8％～34.2％,单条冰川的平均缩小量为0.092～0.415km²,末端平均后退量为 3.5～10.5m/a。由于新疆各流域中冰川的分布、变化特征,以及融水所占河川径流的比例不同,因此,未来气候变化对新疆各个区域水资源的影响程度和表现形式是不同的。分析表明,在塔里木河流域,冰川水资源具有举足轻重的作用,但是,一旦冰川消融殆尽,对该地区将产生灾难性影响,现今该区冰川消融正盛,估计在今后30～50年,只要保持升温,冰川融水量仍会维持。未来20～40年,天山北麓水系中,1km²左右的小冰川趋于消失,大于5km²冰川消融强烈,因此,以小冰川居多的河流受冰川变化的影响较大。东疆盆地水系中的冰川数量少,并处在加速消融状态,河川径流对冰川的依赖性强,冰川的变化已经对水资源量及年内分配产生影响,水资源已经处在不断恶化之中。对于伊犁河与额尔齐斯河流域,未来冰川变化对水资源的影响在数量上可能有限,但会大大削弱冰川融水径流的调节功能。而气候变化对积雪水资源的影响和可能造成的后果应该予以特别关注。     

江苏省矿业权监督管理信息系统开发与应用

针对目前矿业权监督管理的现状,梳理矿业权监督管理流程,建立矿业权监督管理的业务数据库与基础数据库,建立江苏省矿业权监督管理系统,使矿业权监督管理的全过程实现计算机化管理,达到规范管理工作、提高工作效率的目的。     

中国地质遗迹资源保护

在地球形成与演化过程中,由于内外动力共同作用形成了众多具有科学价值和观赏价值的地质遗迹。地质遗迹是地质环境的重要组成部分,因此对于地质遗迹的保护也是自然环境保护的重要部分。中国地质遗迹资源丰富,主要有地层剖面、构造剖面以及古生物化石等。本文系统总结我国地质遗迹分布现状、地质遗迹调查工作进展情况和遗迹保护现状,分析了我国地质遗迹保护工作中存在的主要问题,提出了地质遗迹资源保护与开发利用建议。     

淮河流域地下水资源调查评价与利用研究

在查明淮河流域地下水各含水岩组的水文地质特征、水资源总量、开采现状及存在的环境地质问题的基础上,对该区域地下水资源开发利用潜力进行了详细的评价,并提出了相应的治理措施及促进地下水资源可持续利用的对策,为该区未来更长时期水资源的合理配置和以水资源的可持续利用支撑经济社会的可持续发展提供科学依据。