新疆罗布泊钾盐矿床成因类型探讨

钾盐矿床产于蒸发岩建造中,是含盐盆地发育过程最后阶段的产物.据已往成果及盐类矿物提供的新资料认为罗布泊以卤水钾矿为主,已查明钙芒稍储钾潜卤水承压卤水钾矿床为一种新类型钾盐矿.此外,深层碎屑岩储钾卤水钾矿层及光卤石——泻利盐沉积和杂卤石沉积交代型固体钾盐矿均是有待进一步查证的稀有类型钾矿.深入研究罗布泊钾盐矿床成因,将有...     

剪切带型金矿中金沉淀的力化学过程与成矿机理探讨

剪切带型金矿是一种重要的金矿床类型,有关该类型金矿的成因问题已开展了大量研究,但对于剪切带中金的沉淀析出机制和成矿过程仍存在较大争议,对于赋矿部位的构造属性与矿床关系的研究尚显薄弱。对此笔者整理分析了近年来国内外有关剪切带型金矿的研究进展,并结合我国胶东金矿的研究实例,运用断层阀和力化学理论分析发现,无论是脆性还是韧性剪切带,无论是脉型还是蚀变岩型金矿,其成矿的关键部位均与构造应力集中而导致的脆性破裂(特别是R、T、R’破裂的产生)和碎裂作用以及(多期)岩体侵位密切相关,并且脆性破裂所导致的压力骤降从而引发流体闪蒸的力化学过程可能是造成金沉淀析出成矿的有效机制,其中多期岩体侵位所提供的流体是成矿的物质基础。此外,从国内外实例可以看出,剪切带中的脆性破裂不仅发生于脆性或脆韧性构造域,也可以发生在较深层次的韧性构造域中,尽管韧性域中产生脆性破裂的原因还不十分清楚,但这可能是韧性剪切带成矿的关键机制之一。最后,综合岩体、流体、剪切带三者对成矿的耦合作用,文中提出剪切带型金矿的成矿机理为:(多期)岩体侵位-热液活动-构造剪切-应力集中-脆性破裂(碎裂)产生-压力骤降-流体闪蒸-元素(金)析出,如此循环往复方可形成大型剪切带型金矿。     

盈江盆地盖层氧化带发育特征及其与铀矿化的关系

本文介绍了盈江盆地的构造格架及构造分区、晚第三纪盆地沉积特征 ,对盆地盖层发育的氧化带进行分类 ,论述了氧化带的发育特征及其与铀矿化的关系。认为阻水断裂上方的潜水顺层氧化带及遭受后期潜水顺层氧化的古潜水氧化带铀矿化是区内砂岩型铀矿的主要类型     

关于喀斯特石漠化类型划分问题的探讨

喀斯特石漠化是一种比较特殊的荒漠化类型,我国石漠化研究时间短、涉及学科多、跨部门、跨行业,目前还存在诸多的问题和难点有待进一步深入研究。文章简述了石漠化的发展与研究历程,列举了对喀斯特石漠化科学内涵的代表性观点。针对喀斯特石漠化类型划分问题,综述了目前的分类评价研究现状与进展,指出了其中存在的问题与不足,认为这从一定程度上制约了理论研究以及实践应用的发展。喀斯特石漠化类型的划分应以其成因为基础,体现导致石漠化的根本及内在因素,区别出自然石漠化以及人为石漠化,并能够为石漠化地区生态系统的恢复与重建提供科学依据。     

次生稠油油藏成藏模式研究—以鲁克沁构造带为例

鲁克沁构造带稠油油藏主要为次生油气藏,原油本身低熟,加之成藏过程中多种原因造成轻质组分逸散,进一步稠化而成。该构造带位于库木凸起前缘,长期处于有利的油气指向部位。台北凹陷二叠系桃东沟群湖相泥岩为长期稳定的油气来源。同时,该构造带断层和不整合面非常发育,为油气运移聚集提供了良好通道。通过对该构造带油气运聚规律的认真研究和总结,概括出次生稠油油藏的成藏模式,对吐哈油田下一步对浅层稀油、浅层气、深部气及深部凝析油的勘探具有重要意义。     

济南市新旧动能转换区浅层地下水硝酸盐污染特征

为查清济南市新旧动能转换先行区浅层地下水NO₃^-污染问题,对研究区7种污染源类型64件浅层地下水样品水质结果进行统计分析后认为:受人类活动影响,地下水中NO₃^-含量的高低往往与几种特定的水化学类型存在对应关系。4类主要污染源类型浅层地下水NO₃^-含量一般顺序为:垃圾渗滤液>禽畜养殖>生活污水>农业种植。垃圾渗滤液下渗导致的NO₃^-污染对应的主要地下水化学类型为HCO₃·Cl^-Na·Mg型,粪便渗滤液及尿液下渗主要对应产生HCO₃·SO₄-Na·Mg型、生活污水入渗对应产生HCO₃·Cl^-Na·Ca型,农业种植区主要对应HCO₃-Na·Ca型。离子相关性分析表明,NO₃^-含量与Ca²⁺、Cl^-存在相关关系。研究区以农业种植为主,大量氮素化肥和石灰等土壤改良剂的使用是导致浅层地下水NO₃^-与Ca²⁺相关的主要因素。NO₃^-与Cl^-在地下水中同属较稳定离子,由长期的人类活动排放、入渗积累或蒸发浓缩富集,是一个地区人类活动密集程度和历史长度的综合反映,提出了NO₃^-与Cl^-质量浓度联合评价地下水污染的基本方法。     

中国分省地质灾害图集与主要地质灾害类型

本文阐述了中国分省地质灾害图编图的意义，编图原则和方法，通过分省地质灾害图集的编制和大量资料的综合分析，提出了我国主要地质灾害类型的分类方案，论述了我国地质灾害发育的基本特点与发展趋势。     

Key Groundwater Control Factors of Deep Buried Coalfield by Landform and Sedimentation in the Northern Ordos Basin

There were three landforms (i.e. desert, bedrock platform and loess gully) in deep-buried coalfield of northern Ordos Basin. Water inflow of working face in desert area was 1~2 orders of magnitude larger than that in other landform areas. In order to find out the key controlling factors of the directly water filled aquifers on the roof of the coal seam, we carried out research from the aspects of topography, landform and geological sedimentation. The results showed that desert landform provides abundant recharge water for underlying aquifers because of gentle topography, large precipitation infiltration coefficient, thick and water-rich quaternary system. While bedrock platform and loess gully landform were the water sources with weak recharge capacity of underlying aquifers. The sandstone-mudstone interbedding structure formed by continental deposits resulted in the absence of regional stable aquifers in Jurassic and Cretaceous strata on the roof of coal seams. Pumping tests of boreholes showed that all strata belong to weak to medium water-rich aquifers. The groundwater level of Cretaceous aquifer decreased by 20~130 m in three mines. There was a close hydraulic relationship between shallow and deep aquifers. The Mesozoic strata belonged to fluvial deposits. Qilizhen sandstone and Zhenwudong sandstone aquifers were mainly developed on the roof of the coal seam, which were characterized by thick medium-coarse sandstone sections. The geological and sedimentary conditions of direct water-filled aquifer were similar, but the amount of borehole water, cumulative pre-drainage water and water inflow from goaf in desert geomorphic area were much larger than those in bedrock platform and loess gully geomorphic area. The water-rich of the aquifer was mainly controlled by geomorphology, and the water sources of the deep aquifers were meteoric precipitation and Quaternary aquifer. In different mines with similar Quaternary conditions in Mu Us Desert, there were also great differences in the amount of borehole water, cumulative pre-drainage water and water inflow from goafs. The difference was related to the thickness and lithology of the aquifers. It reflected that the geological sedimentary conditions of the coal seam roof were also important factors to control the water-rich of the aquifers. Topography, landform and geological sedimentation were the key factors to control the water-rich of the aquifer directly and the water inflow from the working face.     

Basic Types and Structural Characteristics of Uplifts: An Overview of Sedimentary Basins in China

The uplift is a positive structural unit of the crust. It is an important window for continental dynamics owing to its abundant structural phenomena, such as fault, fold, unconformity and denudation of strata. Meanwhile, it is the very place to store important minerals like oil, natural gas, coal and uranium. Giant and large-scale oil and gas fields in China, such as the Daqing Oilfield, Lunnan-Tahe Oilfield, Penglai 19-3 Oilfield, Puguang Gas Field and Jingbian Gas Field, are developed mainly on uplifts. Therefore, it is the main target both for oil and gas exploration and for geological study. The uplift can be either a basement uplift, or one developed only in the sedimentary cover. Extension, compression and wrench or their combined forces may give rise to uplifts. The development process of uplifting, such as formation, development, dwindling and destruction, can be taken as the uplifting cycle. The uplifts on the giant Precambrian cratons are large in scale with less extensive structural deformation. The uplifts on the medium- and small-sized cratons or neo-cratons are formed in various shapes with strong structural deformation and complicated geological structure. Owing to changes in the geodynamic environment, uplift experiences a multi-stage or multi-cycle development process. Its geological structure is characterized in superposition of multi-structural layers. Based on the basement properties, mechanical stratigraphy and development sequence, uplifts can be divided into three basic types ? the succession, superposition and destruction ones. The succession type is subdivided into the maintaining type and the lasting type. The superposition type can be subdivided into the composite anticlinal type, the buried-hill draped type, the faulted uplift type and the migration type according to the different scales and superimposed styles of uplifts in different cycles. The destruction type is subdivided into the tilting type and the negative inverted type. The development history of uplifts and their controlling effects on sedimentation and fluids are quite different from one another, although the uplifts with different structural types store important minerals. Uplifts and their slopes are the main areas for oil and gas accumulation. They usually become the composite oil and gas accumulation zones (belts) with multiple productive formations and various types of oil and gas reservoirs.     

康滇地轴中南段元古代地层中铀矿化类型及其特征

本文将康滇地轴中南段元古代地层中的铀矿化划分为３种类型（砂岩型、钠交代岩型和浅变质岩型），其中以钠交代岩型为主，并具有一定的找矿前景。而众所关注的中、上元古界不整合面型铀矿化至今未找到，初步认为其生成条件较差，找矿前景不乐观。