富钾正长岩水热碱法沸石化及成矿意义

本文以富钾正长岩粉体为原料,首次通过直接水热碱法处理,成功合成了方沸石和羟钙霞石,合成温度260℃,时间4 h。通过控制正长岩粉体、氢氧化钠和水的配比,可分别将正长岩粉体中的微斜长石、斜长石和石英转化为方沸石或羟钙霞石,同时正长岩中的K2O和过剩的Si O2被溶出进入液相,可用于制取钾盐。不同类型富钾正长岩直接水热碱法沸石化的成功,为解释自然界中的沸石成因、长石与沸石的共生及转化关系、与沸石化有关的金属矿化机制以及油气成因等,提供了实验证据,也为直接利用廉价的长石类硅铝质矿物原料合成沸石提供了新的技术途径,对于利用非水溶性钾资源制取钾盐具有指导意义。     

大别山北缘响洪甸碱性杂岩体同位素地质年代学

大别山北缘安徽响洪甸碱性杂岩体由正长岩、碱性正长岩及霞石正长岩组成,而霞石正长岩则以团块状、不规则状、透镜状及似层状形式存在于碱性正长岩之中。已有的资料虽然较为全面,但年代学测定所用的方法较为单一,而精确的年龄是讨论杂岩体成因及霞石正长岩与碱性正长岩之间关系的先决条件。     

云南建水县长岭岗碱性侵入岩体岩石特征与成因

云南建水县长岭岗碱性侵入岩体由碱长正长岩、霞石正长岩(广义的)构成。其中霞石正长岩(广义的)可进一步划分为黑云霞石正长岩、霓辉霞石正长岩、黑榴霞石正长岩和霞石正长岩。岩石属过碱性岩石,轻稀土富集,具负铕异常和负铈异常。该碱性侵入岩形成于板块内部环境的可能性较大,可能是在地幔底辟的作用下由地壳下部物质重熔形成。     

云南建水县长岭岗岩体包体特征与岩浆作用

云南建水县长岭岗岩体由碱长正长岩、霞石正长岩(广义的)构成。霞石正长岩(广义的)可进一步划分为黑云霞石正长岩、霓辉霞石正长岩、黑榴霞石正长岩、霞石正长岩。岩石中之包体划分为残余包体、残浆包体、深源捕虏体、浅源捕虏体。岩浆的形成与演化过程中,分离结晶作用明显,混合或混染作用较强。该侵入体的就位机制,很可能属被动就位中的岩墙扩张。在就位过程中有类似热气球膨胀的地质作用。     

霞石正长岩中温烧结反应过程研究

针对国内铝土矿和钾盐短缺、严重依赖进口的现状,综合开发利用储量巨大的非水溶性钾矿具重要意义.本实验以具有典型代表性的云南个旧白云山霞石正长岩为原料,研究了以碳酸钠为助剂烧结反应过程中可能存在的化学反应;并以热力学计算结果为指导,研究了霞石正长岩-碳酸钠体系的烧结配比、烧结时间和烧结温度对霞石正长岩分解率的影响.实验结果表明:在烧结温度1 103 K、烧结时间1 h、霞石正长岩与助剂碳酸钠质量比为1∶0.75时,霞石正长岩的分解率可达98.0%.对霞石正长岩热分解过程的动力学研究结果表明:该过程符合Crank-Ginstling-Braunshtein方程,其表观活化能为78.75 kJ/mol;根据阿伦尼乌斯公式对反应时间进行了预测,认为离子扩散穿透厚度增加的固膜是造成理论与实际反应时间出现误差的主要原因.     

云南个旧霞石正长岩矿床放射性研究

调查个旧霞石正长岩矿床的γ辐射剂量和天然放射性核素含量,查明霞石正长岩在开采过程中放射性污染,为放射环境管理及防治放射性污染提供科学依据。     

广东石岭碱性杂岩的岩石学特征及地质意义

广东石岭碱性杂岩体岩石矿物和岩石化学研究表明,杂岩体以霞石角闪正长岩、角闪正长岩为主,黑云母正长岩等岩石组成,为Ａ－型花岗岩分异结晶作用所形成。产于板内引张构造环境,与深大断裂有关。岩体本身已构成霞石正长岩矿床,具有较高的工业利用和经济价值。     

云南个旧似长石正长岩类及其岩石成因

云南个旧碱性岩体主要的岩石类型有碱性正长岩和似长石正长岩,其中,似长石正长岩中出现大量似长石矿物霞石、方钠石和碱性暗色矿物。本文根据矿物成分及特征,将这些似长石正长岩进一步划分为黑榴霞石方钠正长岩、霞石方钠正长岩、霞石正长岩及方钠霞石正长岩4类。岩石地球化学结果表明,4类岩石的地球化学行为整体表现出过碱质岩的特征,K2O+Na2O含量很高,为钾玄岩系列,同时表现出钾质的特点。分异指数高,呈现高度分异演化特点。稀土元素变化大,轻重稀土元素分异明显,富集轻稀土元素,亏损重稀土元素。微量元素富集大离子亲石元素Th、U及Zr、Hf等高场强元素,亏损Ba、Sr大离子亲石元素,而P和高场强元素Ta、Ti亏损,同时Cr、Co、Ni含量非常低,具有中等的负Eu异常和微弱的负Ce异常。研究表明,似长石正长岩在岩浆演化过程中表现出明显的分离结晶作用特征,且岩浆起源温度较高,约为835℃,起源较深。个旧似长石正长岩为A型岩套A1亚型,结合构造判别图解,认为其可能来自角闪石或者金云母相矿物存在的富集地幔,形成于燕山晚期伸展的构造背景,岩浆在较高温度下高度结晶分异,并在侵位过程中伴随陆壳成分的混染。     

广东从化石岭碱性杂岩的岩石学特征及其地质意义

对广东从化石岭碱性杂岩体进行了１：１万地质调查和填图,并进行了详细的岩石力学研究。其结果表明：杂岩体由霞石角闪石正长岩、角闪石正长岩、墨云母正长岩等岩性组成,为Ａ－型花岗岩的分异结晶作用所形成,产于板内引张构造环境,与深大断裂有关。岩体本身已构成霞石正长岩矿床,具有较高的工业利用和经济价值。     

霞石正长岩烧结反应的热力学分析与实验

霞石正长岩是一种富含K₂O、Al₂O₃、SiO₂的矿产资源。在综合分析云南个旧白云山霞石正长岩物相组成的基础上,对以Na₂CO₃为助剂中温分解霞石正长岩中的铝硅酸盐矿物,提取碳酸钾和氧化铝的技术路线进行了研究。根据热力学理论计算以Na₂CO₃为助剂,主要烧结产物为NaAlSiO₄、KAlSiO₄、Na₂SiO₃时的反应温度,结果表明理论上反应在800 K(527 ℃)左右开始发生。通过烧结反应实验,得到优化反应温度为800～850 ℃,霞石正长岩的分解率达95%以上。X射线衍射分析结果表明,烧结产物的主要物相为NaAlSiO₄、KAlSiO₄和Na₂SiO₃,与热力学计算结果一致。烧结产物的硫酸酸浸实验表明,硅铝分离效果良好,SiO₂、Al₂O₃、K₂O三者的提取率分别高达91.4%、92.2%、92.5%。与前苏联的石灰石烧结法相比,本工艺具有低能耗、低物耗和生产过程清洁高效等优点。     

油页岩灰渣提取白炭黑的方法

以油页岩灰渣制备的水玻璃为原料,结合传统沉淀法和热风干燥工艺成功地制备了白炭黑。实验过程中研究了各种因素对白炭黑性质的影响,并确定了白炭黑的最佳制备工艺：水玻璃中w（SiO₂）为8.1%、c（H₂SO₄）为1.5 mol/L,陈化时间为8 h,反应温度为70～80 ℃,pH值为8.0。透射电镜分析结果表明：采用热风干燥技术制备的白炭黑平均粒径约为50 nm,而且团聚体较少,性能优于烘箱干燥制备的白炭黑。     

Authigenic carbonate burial in the Late Devonian–Early Mississippian Bakken Formation (Williston Basin,USA)

Late Devonian (Famennian) marine successions globally are typified by organic-rich black shales deposited in anoxic and euxinic waters and the cessation of shelf carbonate sedimentation. This global ‘carbonate crisis’, known as the Hangenberg Event, coincides with a major extinction of reef-building metazoans and perturbations to the global carbon cycle, evidenced by positive carbon-isotope excursions of up to 4‰. It has been suggested that authigenic carbonate, formed as cements in sedimentary pore spaces during early burial diagenesis, is a significant mass fraction of the total global carbon burial flux, particularly during periods of low oxygen concentration. Because some authigenic carbonate could have originated from remineralization of organic carbon in sediments, it is possible for this reservoir to be isotopically depleted and thereby drive changes in the carbon isotopic composition of seawater. This study presents bulk isotopic and elemental analyses from fine-grained siliciclastics of the Late Devonian–Early Mississippian Bakken Formation (Williston Basin, USA) to assess the volume and isotopic composition of carbonates in these sediments. Carbonate in the Bakken black shales occurs primarily as microscopic disseminated dolomite rhombs and calcite cements that, together, comprise a significant mass-fraction (ca 9%). The elemental composition of the shales is indicative of a dynamic anoxic to sulphidic palaeoenvironment, likely supported by a fluctuating chemocline. Despite forming in an environment favourable to remineralization of organic matter and the precipitation of isotopically depleted authigenic carbonates, the majority of carbon isotope measurements of disseminated carbonate fall between −3‰ and +3‰, with systematically more depleted carbonates in the deeper-water portions of the basin. Thus, although there is evidence for a significant total mass-fraction of carbonate with contribution from remineralized organic matter, Bakken authigenic carbonates suggest that Famennian black shales are unlikely to be sufficiently ¹³C-depleted relative to water column dissolved inorganic carbon to serve as a major lever on seawater isotopic composition.     

湘中桃江中奥陶统黑色岩系岩石学地球化学及成因

桃江中奥陶统黑色岩系主要由黑色页岩等七类岩石组成,主要矿物为伊利石、绿泥石、玉髓等。该岩系经历了强的晚期成岩作用。碳同位素(δ~(13)C=-9.35～-20.13‰)等特征表明硫酸盐还原作用形成了富~(12)C的成岩碳酸盐矿物。黑色岩系富Mn、Ba等元素,B-V图解表明它们为海相,V/Cr值表明其形成于还原环境。湘中中奥陶统黑色岩系的空间分布、几何形态等表明其形成与氧最小带有关。     

Depositional environment of a Kimmeridgian carbonate 'black band' (Akkuyu Formation, south-western Turkey)

The Upper Jurassic Akkuyu Formation of south-western Turkey consists of pale-coloured carbonate facies, but includes a peculiar ‘black band’ at its base. In order to characterize the depositional environment of this level, a sedimentological, organic and inorganic geochemical study was performed on 30 samples. Three units are distinguished. Unit 1 consists of black marlstones, very rich in organic carbon (22–30%) with HI (hydrogen index) values around 600. The organic matter is an amorphous homogeneous material even at nanoscopic scale. This unit is also characterized by a very high concentration of V ( >1000 p.p.m.) and a δ¹³C_org value around ?26·5‰. Unit 2 shows thin-bedded black limestones with chert layers. Its organic content varies from 2% to 6%. As in unit 1, the HI values are uniformly high (600), and gas chromatography shows a high quantity of hopanes. The V concentration is also high (≈400 p.p.m.). The unit has a high Sr/Ca ratio, an organic carbon isotopic ratio close to ?28·7‰ and diffuse, nanoscopically amorphous organic material that is closely associated with pyrite. Unit 3 corresponds to the white limestones overlying the ‘black band’. This calcitic facies is almost devoid of organic carbon (<0·1%). The δ¹³C_org values are similar to those of unit 1 (?25·5‰ to ?26‰). Deposition occurred in a basinal environment surrounded by a carbonate platform. Primary productivity was high but not exceptional; terrestrial organic inputs were scarce. Bottom waters were probably euxinic during the deposition of unit 1. The presence of both hopane-rich and sulphur-rich nanoscopically amorphous organic matter may be the result of strong sulphate-reducing bacterial activity. Coupled with low amounts of iron, this led to intense vulcanization of the organic matter and thus good preservation. With the onset of unit 2 deposition, environmental conditions became less extreme, perhaps because of cooler water temperatures. Finally, the depositional conditions became oxic, leading to the accumulation of pale-coloured organic-poor limestones of unit 3.     

湖南桃江奥陶系磨刀溪组锰质岩的内碎屑结构和重力流沉积

湖南桃江一带的奥陶纪锰质碳酸盐岩,具有清晰的内碎屑结构和一些粒度递变沉积构造。锰质岩或锰矿层呈薄层或条带夹在含有笔石的黑色泥页岩中,表现出它们在成因或沉积环境方面的极不协调。以砂屑和藻屑为主组成的白色、灰白色锰质碳酸盐岩是清洁、浅水、碱性环境中的产物;以细粉砂级颗粒为主并含有硅质、碳质的泥页岩则是污浊、深水、酸性环境中的沉积。这种不协调的沉积组合是由于浅水锰质碳酸盐沉积物以重力流方式进入深水盆地与黑色泥质沉积物混合、交互沉积结果。     

Effect of activated carbon on microbial-induced calcium carbonate precipitation of sand

Microbial-induced calcium carbonate precipitation (MICP) is a sustainable technique to transform or improve physical and mechanical properties of soils. This paper aims to study the effect of activated carbon (AC) on the property of bio-treated China Standard sand. Six sample groups were prepared considering various dosages of cementation solutions and bacterial suspensions. In each group, samples were prepared at six different AC ratios (0%, 0.2%, 0.5%, 1%, 2%, and 3% by weight of sand). Bacterial retention ability, calcium carbonate mass, unconfined compression strength (UCS), and microstructures of bio-treated samples were examined and evaluated in the presence of AC. It was found that the improved yield of calcium carbonate crystals and increased UCS were correlated to the enhanced bacterial retention ability attributed to AC. In addition, the test results showed that the amount of cementation solution played an important role in the MICP process, but volume variation of the bacterial suspension had a little effect on the bio-treated samples.     

矿物材料与环境污染治理—以粘土矿物和沸石为例

矿物的性能，矿区地质测试和吸附能力实验表明，粘土矿物和沸石等矿物材料对于Cr,Cd,Pb,Hg,As等有害元素具有很强的吸附能力，是理想的低成本吸附剂，在废水处理中可用来取代活性炭或离子交换树脂来去除重金属等有害元素。     

四川盆地广元地区大隆组有机质富集规律

四川盆地西北广元地区上二叠统大隆组主要为碳酸盐岩、硅质岩和页岩互层沉积.对四川广元长江沟剖面进行精细解剖的结果表明,大隆组中有机碳质量分数为0.16%~14.6%,有机碳质量分数与岩性关系密切,高有机碳质量分数赋存于黑色页岩和纹层状灰岩中,其中碳酸盐岩的有机碳质量分数与纹层厚度呈反比,即纹层厚度越大有机碳质量分数越低.大隆组优质烃源岩位于大隆组中部岩段,岩性组合为黑色页岩和硅质岩互层,间夹薄层状灰岩或纹层状灰岩.微量元素分析结果显示有机质的富集明显受控于沉积阶段及早期成岩阶段的氧化还原条件.综合分析表明大隆组烃源岩有机质富集受晚二叠世沉积环境、氧化还原条件、生物生产力、深部热液流体的影响,其中厌氧、缺氧环境是大隆组烃源岩发育的主控因素,高生物产率是有机质富集的前提条件.     

黄龙钙华有机碳测定方法的对比研究

中国四川黄龙钙华不仅具有重要的旅游价值,其有机碳含量对确定区内钙华沉积规律和环境生物的作用与贡献也具有重要意义。钙华有机碳测定的前提是有效去除无机碳,较好保留有机组分并测定,才能够准确地为生物参与钙华沉积提供依据。本文采用酸溶法、消解法、容量法对钙华有机碳含量进行了测定,结果表明:酸溶法会改变有机碳在钙华中所占质量分数,测试结果偏高,并且相对标准偏差(RSD)为23.73%~30.95%,精度较差;消解法对黑色、黄色两种钙华有机碳的测试较为准确,但对白色钙华的测试精度不够理想;容量法测试结果的RSD为3.27%~11.11%,在测定时受钙华组分中干扰物质和外界因素影响。通过横向对比这3种方法的优缺点和测试误差来源,认为消解法适用于钙华有机碳测定。     

内蒙古二连盆地白音查干凹陷下白垩统腾格尔组热水沉积过程中矿物沉淀顺序及其控制因素*

基于岩心、岩石薄片及元素分析等资料,通过偏光显微镜、定量矿物扫描(QemScan)、电子探针、能谱和流体包裹体分析等技术手段,探讨了二连盆地白音查干凹陷下白垩统腾格尔组热水沉积岩中热水沉积矿物的沉淀顺序。研究区热水沉积矿物主要为铝硅酸盐和碳酸盐,含少量黄铁矿、重晶石、萤石等矿物。这些矿物在空间上具有特定的先后关系或位置关系: (1)在纹层状岩层中,由下到上从铝硅酸盐过渡为碳酸盐。在铝硅酸盐矿物组合中,首先出现的是方沸石,其次是钠沸石,再次为钠长石;在碳酸盐矿物中,首先出现的是菱镁矿,其次是菱铁矿,再次为铁白云石,有时还可见到方解石,但其含量很低。(2)在凝絮状团块中,团块中心为黄铁矿,从中心向外依次过渡为方沸石、钠沸石、菱镁矿、菱铁矿,最外层为铁白云石。在纹层状岩层和凝絮状团块中,有时还能见到上述顺序的逆顺序。(3)在后期充填的裂缝中,边部为沸石或绿泥石等铝硅酸盐矿物,向中心逐渐过渡为铁白云石碳酸盐。综合研究区所有的矿物序列来看,最完整的序列应为黄铁矿—钾长石—方沸石—钠沸石—钠长石—菱镁矿—菱铁矿—白云石—方解石,但是这种完整的序列是不常见的,通常仅为其中某几种矿物的组合,然而不管是哪些矿物进行组合,其出现的顺序都不变。推测该矿物序列的类型受热液喷流和溢流阶段、时间、温度和热水化学性质控制,早期高温、高盐度条件下出现的铝硅酸盐矿物序列较多,而晚期主要形成碳酸盐矿物序列。