短波红外伊利石结晶度在新疆白杨河铀矿床勘查中的应用

短波红外伊利石结晶度是云母族矿物的重要光谱参数,与矿物的形成温度密切相关,通常用来指示可能的矿化/热液中心。本文使用FieldSpec4可见光-短波红外地面非成像光谱仪对新疆白杨河铀矿床地表进行光谱测试与分析,发现矿床主要蚀变矿物伊利石结晶度具有明显的变化规律：矿床北缘接触带短波红外伊利石结晶度变化范围为0.7～2.0,大部分伊利石结晶度大于1.0,少部分小于1.0;矿床南缘接触带短波红外伊利石结晶度变化范围为0.3～1.0,多数伊利石结晶度小于0.7,矿床北缘接触带伊利石结晶度明显大于南缘接触带,同时矿床北缘接触带为铀矿化富集部位,结合相关地质资料,可以推断北缘接触带为矿床可能的矿化/热液中心,这可以为白杨河铀矿床铀矿勘探提供参考与借鉴。     

深海热液生物群落研究综述

深海热液口吸其生物群落自1977年发现以来,受到海洋学界和生物界的广泛关注,并在热液生物生理、生态和生物地理学等方面取得了显著的进展.本文就该领域的研究进展做一简要的综述,主要内容包括热液生物群落的基本特征、种类组成和时空变化.     

Dating of sediment－hosted disseminated－type gold deposit by using ^40Ar／^39Ar laser probe： A case study of Changkeng large－scale gold deposit, China

Hydrothermal clay minerals that formed in the main metallogenic stage of the Changkeng disseminated-type gold deposit in central Guangdong were analyzed by the 40Ar/39Ar laser probe. The results give Ar-Ar isochron ages of 109.9 1.4 to 110.1 1.3 Ma, which are 30 to 50 Ma older than the age of silver ore bodies in the deposit. Both gold and silver mineralizations were not related to hidden granite batholith in the mining district, but probably related to evo-lution of sedimentary basins. This study shows that the 40Ar/39Ar laser probe is a sound dating tool applicable to sediment-hosted disseminated-type gold deposit.     

黔西南赵家坪矿带地层中汞金地球化学研究

通过对地层中汞、金的某些沉积作用和地球化学特征的研究,认为赵家坪矿带内各地层中的汞、金曾参加了同生沉积作用。由于黔西南普遍存在着玄武岩喷发对地层中汞金含量在时间上和空间上的直接和间接控制作用,使地层中的汞、金含量达到了初始富集,即形成了矿源层。再经构造热液改造矿源层而成矿。     

XW铀矿床成矿物理化学条件

XW铀矿床为产于花岗岩断裂破碎带中的大型热液铀矿床。沥青铀矿是矿石中唯一的原生铀矿物,其共生矿物主要有石英、萤石、赤铁矿和黄铁矿。该文主要用包体矿物学和热力学的方法,研究了矿床的成矿物理化学条件。结果表明,铀从迁移到沉淀的过程,实际上是热液HCO_3~-含量显著减少,热液温度、压力和pH值降低而氧化性增强的过程。铀沉淀发生在中低温(150—250℃)、弱酸性(pH≈4.69—5.09)、贫HCO_3~-、相对氧化性的低压介质中。     

Microbe-related precipitation of iron and silica in the Edmond deep-sea hydrothermal vent field on the Central Indian Ridge

Microbial mats, several millimeters thick and brown-yellow to white in color, were collected in hollow inside of chimney structure from Edmond hydrothermal field on the Central Indian Ridge. Microbes with shapes of rod and helical stalk-like filaments were observed in the microbial mats, and are com- monly characterized by their cells completely encrusted by thick mineralized layers, made up of large amounts of amorphous silica and minor amounts of iron oxides. Transmission Electron Microscope observation has demonstrated that the acicular Fe-bearing matter was not only heterogenously dis- tributed on the surface of the cell wall, but also deposited in the inside of cell, suggesting that bio-precipitation of Fe had occurred both on the surface and in the interior of cell. Microbial silicification was also commonly found in the mats. Silica usually precipitated homogeneously on the surface of the microbes and forms micro-laminated layers, which might be controlled by the inorganic process of precipitation in hydrothermal environment. The biomineralization phenomenon in the mi- crobial mats showed that the precipitation of Fe and Si was closely related to microbes in hydrothermal environment. Considering that hydrothermal activities provided required chemical elements for miner- alization, it is suggested that this biomineralization process also might be driven by hydrothermal ac- tivities at the sea floor to some extent.     

青海然者涌铅、锌、银多金属成矿地质条件浅析

青海然者涌铅、锌、银多金属矿床地处藏北唐古拉成矿带,子曲铜钼铅锌成矿带的中段,成矿地质条件优越,找矿前景广阔,研究程度较低,故从成矿背景、构造、地层、岩浆岩、热液等成矿地质条件进行初步探讨,为找矿方向提供参考。     

青山铅锌矿床两种热液混合成矿的锶同位素证据

对青山铅锌矿的锶同位素测试表明它的组成符合二元混合模型，通过其他地质与地球化学的研究表明本区铅锌矿系由两种成矿溶液混合形成的。     

西秦岭铀矿床热液石英Pb同位素组成及其应用

作者分析了西秦岭地区各类岩石、花岗岩、含铀黄铁矿及早阶段热液石英Ｐｂ同位素组成，并将热液石英Ｐｂ同位素组成作为联系母源Ｐｂ与矿床Ｐｂ同位素组成的桥梁，与母源Ｐｂ及矿床Ｐｂ同位素组成进行了对比，花岗岩－石英－含铀黄铁矿Ｐｂ同位素组成具有线性演化关系，从而提出矿床中的铀来自隐伏构造－岩浆岩，而不是地层岩石。