示踪技术在水库绕坝渗漏研究中的应用

文章以黑洞湾水库左坝绕坝为例,介绍了利用天然渗流中的湿度,电导以及同位素示踪;定性,定量的测量和分析大坝的渗漏路径的技术和方法,并为水库渗漏的正确处理和治理途径提供了科学的数据。     

东北地区5 000 aB.P.～4 700 aB.P.左右的降温事件及对考古文化的影响

距今5000年左右世界各地普遍存在一次幅度较大的短期降温气候事件，通过对金川剖面泥炭地层14C测年，孢粉分析，认为东北地区此次降温事件结束的14C年龄在4700aB.P.左右，降温事件出现之前气候温暖湿润，降温事件过后温度持续下降，金川剖面的记录与东北地区其它类型沉积物所记录的降温事件出现的时间基本吻合，降温事件对燕辽地区古文化演变产生了深刻的影响。     

广西晚元古代本洞岩体同位素年代学研究

本洞花岗闪长岩体是目前在我国南方发现的一期最老的花岗岩类侵入体。对该岩体进行系统的同位素年代学研究和形成年龄的确定,无论是对我国南岭地区花岗岩的研究还是对我国南方前寒武纪地层的划分与对比都具有十分重要的意义。     

西藏东部大气降水氧同位素组成特征

The Xizang Plateau, with a common altitude of more than 4000 m sbove sea level,has long been celebrated as “The Roof of the World”. In order to study oxygen isotopic composition of meteoric water in the Xizang Plateau Region and its relationship with the attitude, we made an investigation tour to the Xizang Plateau, starting from Guizhow, during 1979 from July to October, and 79 meteoric Water samples were collected, including brook, well, lake, snow, firn, spring and running waters, at different altitudes. Oxygen isotope analyses indicate that the isotopie composition of meteoric water in the areas more than 4000g and in the western parts of SichuanGaizhow shows remarkable altitude effect. There is a negative correlation between δ^28O and altitude, which is reflected by --δ^18O = 0.0026H 7.75. The average δ^18O value for metcoric water in the areas: more than 4000m above sea level turns out to be --18.15‰ is evident that δ^18O value for lake water on the plateau is related to its water supply. δ^18O value for lake water, in which the evaporation is greater than supply,is approximately three or four times higher than that of supplied water, averaging -5.74‰. Oxygen isotopic compasition of geothermal water can be compared with that of local meteoric water, but shows certain δ^18O-shift, suggesting that the main water-supply source seems to be meteoric water in the same area.     

白云鄂博REE-Nb-Fe矿床成因的氧、碳和锶同位素及微量元素地球化学证据

根据白云鄂博赋矿白云石大理岩的岩石学特征及地质产状将其分为两类：粗粒和细粒白云石大理岩．它们的氧、碳和锶同位素及微量元素地球化学特征显然有别于分布在宽沟背斜以北典型的沉积石灰岩和白云岩,而和幢源火成碳酸岩十分相似．与矿床进行对比研究说明,成矿流体和矿质主要起源于碳酸岩浆的分异作用,其放射性成因同位素和微量元素保持了地但指纹,而氧和碳同位素组成却向壳源方向漂移,证实碳酸岩浆侵位过程中受大陆地壳的混染作用非常微弱,但是由碳酸岩浆活动所引起的成矿热液体系中却有一定的地表水混人认为白云鄂博REE-Nb-Fe超大型矿床的成因应归属于火成碳酸岩型矿床．     

广西某矿田磁黄铁矿的研究及其区别特征

Naturally occurring hexagonal and monoclinie pyrrhotites have been recognized by X-ray diffraction analysis and DTA from an ore deposit in Guangxi. They are distinguishable from each other in magnetism, reflectivity, hardness and some other properties. A correct distinction between hexagonal and monoclinie pyrrhotites is of practical importance in prospecting and theoretical study.     

大洋玄武岩的三元混合特征及地幔的三元结构模式

本文综合分析了新生代大洋玄武岩的Pb,Sr,Nd同位素特征，并利用同位素混合方程，差别出大洋玄武岩均显示出很好的三元混合特征，提出了大洋地幔的三元结构模式。三个地幔端员成分分别代表了亏损地幔，高U/Pb比和高Th/Ph比地幔，富集地幔。修正了过去利用Sr-Nd负相关关系得出的二元地幔结构模式，作出了大洋玄武岩的Pb-Sr-Nd同位素相关图，并论证了Zindler等（1982）提出的“地幔面”是不存在的。本文还对部分岛孤及大陆玄武岩进行了讨论。     

加扎韦特（阿及尔利亚）海洋沉积物中的钚同位素,^137Cs,^90Sr和天然放射性

在切尔及利亚西海岸的小湾湾加扎韦特采集了不同粒度的海洋表层沉积物样品，并对其进行了研究，以测量α、β和γ放射性。本次研究的目的是探测放射性污染。使用把γ能谱，放射性化学分离和α能谱、β计数相结合的方法，测定了样品中大部分有意义的天然放射性同位素的活度。