黔中开阳磷矿沉积区震旦纪陡山沱期定量岩相古地理重建*

磷矿的沉积和成矿与成磷期的古地理环境密切相关。本文首次将“单因素分析多因素综合作图法”运用于开阳地区震旦纪陡山沱期沉积型磷矿床的成矿分析和找矿预测上。通过选取陡山沱组及其各岩性段的地层厚度及磷矿层品位作为单因素,确定开阳地区古地理格局;结合地层岩性组合、沉积特征等多因素综合分析,恢复开阳地区成矿期沉积环境,编制陡山沱早期、中期和晚期岩相古地理图。根据定量岩相古地理重建结果,认为开阳地区陡山沱期整体处于南靠黔中古陆、地势南高北低、局部地形复杂的滨岸海滩沉积环境,其中临滨带为最有利成矿带,局部地形变化也会造成矿层厚度、品位的差异;矿层受到的水流冲蚀、暴露、淋滤及再沉积作用是导致矿石品位显著提升的关键因素。通过定量岩相古地理学精确还原成矿期古地理环境、解析多期次沉积成矿过程,对于确定磷矿控矿因素、构建找矿预测模型和预测矿体空间位置具有重要意义。     

Diurnal Variations of Hydrochemistry in a Travertine-depositing Stream at Baishuitai, Yunnan, SW China

Diurnal variations of hydrochemistry were monitored at a spring and two pools in a travertine-depositing stream at Baishuitai, Yunnan, SW China. Water temperature, pH and specific conductivity were measured in intervals of 5 and 30 min for periods of 1 to 2 days. From these data the concentrations of Ca²⁺, HCO₃⁻, calcite saturation index, and CO₂ partial pressure were derived. The measurements in the spring of the stream did not show any diurnal variations in the chemical composition of the water. Diurnal variations, however, were observed in the water of the two travertine pools downstream. In one of them, a rise in temperature (thus more CO₂ degassing) during day time and consumption of CO₂ due to photosynthesis of submerged aquatic plants accelerated deposition of calcite, whereas in the other pool, where aquatic plants flourished and grew out of the water (so photosynthesis was taking place in the atmosphere), the authors suggest that temperature-dependent root respiration underwater took place, which dominated until noon. Consequently, due to the release of CO₂ by the root respiration into water, which dominated CO₂ production by degassing induced by temperature increase, the increased dissolution of calcite was observed. This is the first time anywhere at least in China that the effect of root respiration on diurnal hydrochemical variations has been observed. The finding has implications for sampling strategy within travertine-depositing streams and other similar environments with stagnant water bodies such as estuaries, lakes, reservoirs, pools and wetlands, where aquatic plants may flourish and grow out of water.     

Age and Thermal History of the East Ore Section,Bayan,Obo Deposit—A Fission Track Study

Considerable attention has been paid in recent years to the study of geothermal history by using spontaneous fission tracks of 238U recorded in minerals.Apatite and zircon were used for fission track study in this paper because apatitie has been widely used as a natural geothermometer(Wang Shicheng et al., 1994) to reveal the thermal evolution of sedimentary rocks based on its low annealing temperature of fission tracks and zircon is characterized by a closing temperature above 700℃,The samples were collected from ferruginous,siliceous slate wall rock at the upper levels of the orebody and Nb-REE-Fe ores from deep tunnels.The age and thermal evolution of the orebody were discussed in terms of fission track characters and their length variations observed in the coexisting apatite and zircon in the same specimen.     

微压流化式复合生物反应器的同步脱氮

通过对曝气系统的调节,微压流化式复合生物反应器（MP-FHBR）内可以实现好氧区和缺氧区共存,利用这一特点和MP-FHBR中同时存在的活性污泥﹑悬浮生物膜复合生物体系,进行了同步脱氮的试验研究。结果表明,MP-FHBR在好氧-缺氧条件下,实现了同步脱氮过程,TN和COD的平均去除率分别达到77.5%和98.3%。降低DO质量浓度使反应器内形成完全缺氧环境,对MP-FHBR同步脱氮效果没有显著影响,但会降低系统去除COD的效果;而提高DO质量浓度使反应器内形成完全好氧环境,MP-FHBR同步脱氮效果显著下降。在一定范围内提高进水COD/TN有利于提高MP-FHBR同步脱氮效果,COD/TN 由2升高到10,TN平均去除率由58.4%提高到78.8%,而继续提高COD/TN对系统同步脱氮效果的影响并不明显。在反应器允许的条件下,提高污泥质量浓度(MLSS)有利于提高系统反硝化脱氮效果,TN去除率随MLSS的增加而提高。     

岩浆型磷灰石结构四面体替换特征的标型意义

根据文献中列了的５６个产于碳酸岩－碱性岩磷灰石的成分数据，讨论了这些岩浆型磷灰石结构四面体替换特征的标型意义，并定义出四面体替换指数，（ＴＳＩ＝（Ｓｉ＋ＳＣ）／Ｐ，单位晶胞原子数百分比），以区别侵入相碳酸岩磷灰石，喷发相碳酸岩磷灰石和碱性岩磷灰石：ＩＡＰ的ＴＳＩ为０－６．９，平均３．６２，仅少量Ｃ进入Ｔ位置；     

东帕米尔变质核杂岩构造的厘定

卡拉库鲁木变质核杂岩是慕土塔格岩体的南缘部分，由长城系片麻岩以及燕山期花岗岩组成，其中长城系片麻岩为一套低角闪岩相的变质侵入岩，主要岩性为（石榴石）黑云二长片麻岩、（石榴石）黑云斜长片麻岩；根据变形程度，将其划分为内带、中带及外带，其中在内带见有燕山期花岗岩。剥离断层沿变质核杂岩边缘呈向南凸出的弧形展布。剥离断层上盘滑脱体由长城系赛图拉岩群高绿片岩－低角闪岩相的变质岩系构成。变质核杂岩构造的形成时代为早－中侏罗世。     

数学地质的主要进展和发展趋势

数学地质是地质学的一个重要的新分支。本文涉及数学地质在几个领域的主要进展,分形、耗散结构、灰色系统模型和模糊数学在地质学中的应用。分形已成功地应用于准晶体微粒结构、断层系统和地质构造分布、多孔介质、地质体表面粗糙度和其他问题研究。耗散结构已应用于矿物离解过程、热液成矿作用动力学、混合岩成因以及地壳地幔的结构和运动等的研究。灰色系统理论在水文地质、工程地质、环境地质和矿床预测的很多问题中得到应用。模糊数学是解决很多地质问题的有用的定量工具。最后,讨论了数学地质的进一步发展趋势。     

塔中古溶洞见证晚奥陶世抬升幅度

塔中隆起区上奥陶统良里塔格组灰岩与桑塔木组砂—粉砂岩之间为不整合接触,昭示着这两个组沉积期之间存在一次历时约百万年的区域性构造抬升事件。中古31井良里塔格组三段的4 125.6～4 133.9 m井段为垮塌型溶洞沉积,洞顶距良里塔格组二段顶部190.6 m,溶洞中角砾状充填物主要来自良里塔格组洞壁本身的礁相灰岩,且见数厘米厚的暗河流水沉积纹层,未发现源于其它时代的颗粒混杂其间。这一事实指证了溶洞的形成和充填时代均为良里塔格组沉积之后、桑塔木组覆盖之前的晚奥陶世凯迪中期。具溶蚀力的淡水潜流带的深度一般不低于周围的海平面,由此可推断出该井区这次抬升出海平面之上的高度,即使忽略良里塔格组顶部可能经地表剥蚀的良里塔格组一段,抬升出水面部分至少也应该有190 m,藉生态地层学恢复洞壁礁灰岩沉积时的海水深度约为30 m±,因此总抬升幅度至少能达到220 m。     

湘黔新晃-天柱重晶石矿床微量稀土元素和硫同位素研究

湘黔新晃-天柱地区的早寒武世重晶石成矿带是世界上最大的重晶石矿集区,在全球范围内具有代表性,对其进行 研究具有重要的科学意义。本文通过对新晃-天柱地区的重晶石矿床微量稀土元素和硫同位素研究表明：所有样品的 、比值以及重晶石含矿岩系稀土元素具有明显的负异常表明重晶石矿床形成时处于缺氧还原环境;重晶石矿石 表现出明显的正异常,反映了成矿过程受到了较强的海底热液物质的影响,表明钡可能主要来自于海底热液喷流物质; 重晶石的δ3值主要分布在,表现出重硫富集的特征,且重晶石硫同位素呈塔式分布,表明硫源来源单一,主 要来自同期海水硫酸盐。黄铁矿δ3值低于同期海水硫同位素组成,表明生物细菌对海水硫酸盐的还原起到了很大作用, 并且反映了矿床形成于海水交换有限的滞留的海盆系统。综合以上分析认为重晶石成矿时期为海底缺氧、热液活动频繁、 封闭半封闭的台地泻湖环境。     

Analysis of the ore-controlling role of Guojiadian mantle branch structure, Northwest Shandong Peninsula, China

Metallogenesis in the gold ore-concentrated zone of Northwest Shandong Peninsula is closely related to deep processes.The region in the eastern part of North China entered into the stage of mantle plume evolution during the Yanshanian movement,following the long-time stage of stable platform evolution during Paleozoic time.At that time,the ore-concentrated zone of Northwest Shandong Peninsula just entered into the development-evolution stage of the Laiyang sub-mantle plume and the Guojiadian mantle branch structure in its periphery.The core-mantle-source gold was present in the gas-liquid form,and it migrated through mantle plume→sub-mantle plume→mantle branch structure→favorable tectonic expansion zone to the favorable loci of the mantle branch structure,where gold was deposited as ores,thereafter constituting a series of large-to medium-sized gold deposits distributed around the Guojiadian mantle branch structure.This study also dealt with the Jiaojia fault as the main detachment(fault altered rock) belt on the northwestern margin of the mantle branch structure and also presented a basic cognition about the fact that the Sanshandao fault as the listric fault on the hanging wall of the detachment belt.Furthermore,on this basis,this study also pointed out the orientation for further ore prospecting in this region.