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世界各国大型古代海相固体钾盐矿床多数是在石油、盐岩矿、盐泉卤水等资源的勘查过程中被发现的。国内几十年的找钾实践证实,我国缺乏大型海相固体钾盐矿床,近年来在新生代陆相沉积盆地中寻找大型固体钾盐矿床的努力也没有取得明显进展。我国已探明的钾盐储量主要分布在青海柴达木盆地和新疆罗布泊的11个盐湖及其晶间卤水中,约占资源总量的90%以上;以固体钾矿赋存的资源量少且品位不高,仅占己知总量的2.6%。从1958年察尔汗盐滩生产出第一批953吨钾肥填补我国钾肥生产的空白,到年产150万吨KCl的卤水钾盐开发规模的形成;从1995年在罗布泊发现大型卤水钾矿,到2008年预期生产120万吨K2SO4,显示了我国干旱区盐湖卤水钾盐资源的重要位置。有专家建议,今后的工作应在深入研究成盐盆地基底构造和岩相古地理的基础上,进一步划分可能成钾的次级盆地并进行重点勘探和研究。借鉴世界各国找钾经验,将地质观察分析、地球物理探测、地球化学与水化学等方法综合运用,我国的探盐找钾工作有可能取得突破性进展。 相似文献
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以昌都—兰坪—思茅盆地及呵叻盆地含盐带盐类沉积为研究对象,在分析总结前人研究成果的基础上,通过系统的大地构造学、矿床学、地球化学等研究方法,总结和研究了该区含钾蒸发岩矿床的矿床特征,提出了新的成矿模式。研究表明,兰坪—思茅盆地和呵叻盆地的含钾蒸发岩矿床为"海源陆相"成因,即在陆相环境下与海水的变异有关。该矿床缺失正常海水蒸发浓缩而形成的硫酸盐沉积,同时,矿床中少量菱镁矿等自生矿物的出现无法用正常海水蒸发理论解释。矿床中少量溢晶石等矿物的出现预示着该矿床富钙。兰坪—思茅盆地内广泛发育了白垩纪蒸发岩系(勐野井组或云龙组),江城地区甚至沉积了小型钾盐矿床。同位素和微量元素的研究表明,该区蒸发岩矿床为海相成因,Rb和Br的含量变化指示海水从北部兰坪侵入到呵叻。昌都及兰坪地区的白垩纪石膏硫、锶同位素研究表明,该区大套的硫酸盐沉积为海相成因,物源研究成果揭示思茅盆地的物源可能来自东羌塘地区,预示着昌都地区的硫酸盐沉积跟兰坪—思茅盆地的蒸发岩沉积具有同源性。通过上述研究,提出了多级盆地海水迁移变质成盐成钾模式。 相似文献
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呵叻高原是世界上最大的钾盐矿床之一,老挝万象盆地是呵叻高原北部沙空那空盆地的一个次级盆地,通芒矿区则是万象盆地钾盐矿床的重要组成部分。近期,大量钾盐地质勘探工作的实施为该地区钾盐沉积的研究提供了良好条件和物质基础。研究表明,含盐地层包括上、中、下3个盐段,巨厚钾镁盐主要富集在塔贡组下盐段。盐类矿物主要包括石盐、光卤石、钾石盐、水氯镁石、溢晶石、硬石膏等,还包括一些碳酸盐和硼酸盐矿物。矿石类型以光卤石矿为主。含盐层位的Br含量、Br×103/Cl比值在剖面上的变化指示了成盐期卤水不断蒸发浓缩,最终形成了具有重要经济价值的钾镁盐矿床。与世界其它海相及陆相钾盐矿床对比表明,通芒矿区钾盐沉积具有明显的海相特征,成盐成钾物质应该来自海水。 相似文献
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兰坪—思茅盆地是国内唯一发现古钾盐沉积的盆地。对云南兰坪—思茅盆地钾盐成矿背景作了总结与分析,指出中生代以来盆地经历了陆内裂谷形成到消亡、侏罗纪箕状断陷盆地发育、早白垩纪双断式断陷盆地发育、早白垩晚期干化成盐和后期挤压走滑几个阶段。在此基础上通过盐系地层沉积特征的分析,得到了盆地在成盐期(早白垩世晚期)构造活动强烈,由统一的湖盆解体为多个次级成盐盆地,盐类资源的沉积应该分属不同的沉积序列的认识。兰坪—思茅盆地成盐期构造背景分析对于了解该区蒸发岩矿床特征和成矿机理具有重要的参考意义。 相似文献
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可可西里古近系含盐系地层沉积特征及古盐湖成盐模式讨论 总被引：1，自引：1，他引：0
可可西里是羌北—滇西构造域中重要的新生代沉积盆地,其古近系红层是认识中国陆相微陆块成盐作用的重要窗口。该区南部沱沱河盆地、北部错仁德加盆地古近系雅西措群地层中明显包含两套含盐系地层,两套层系形成的时代、古气候条件相同,但古地理条件、古盐湖盆地规模、成盐机制各异。渐新世时期沱沱河盆地属于封闭型的干盐湖沉积,错仁德加盆地属于开放型干盐湖沉积环境,预示着青藏高原中部渐新世大可可西里盆地并非相互连通,其中小型盆地的沉积成盐环境存在差异。 相似文献
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位于青藏高原腹地的羌塘盆地是我国最大的中生代海相含油气盆地,盆地发育多套生储盖组合,其中蒸发岩的膏盐层往往作为油气藏研究的盖层。但盆地内蒸发岩大多只达到硫酸盐沉积阶段,盆地内是否存在古钾盐矿？最佳的钾盐矿成矿有利区域具体位于何处？保存的远景资源量有多少？通过青藏高原形成过程中微地块的碰撞和拼合历史。研究羌塘盆地中生代沉积和演化过程,厘清羌塘盆地钾盐主要富集在中生代侏罗系的局限台地相区域。结合地震勘探和构造演化史恢复,阐明只有在逆冲推覆构造之下的区域才可能保存钾盐矿。根据羌塘盆地侏罗系夏里组沉积相带分布范围,推测保存钾盐矿的两个有利区主要位于安多县北西方向,面积约8 000 km2。综合地表膏盐层分布和地球物理勘探推断的羌塘盆地中侏罗统石膏层厚度分布图,根据海水中析出石膏和钾盐的比例,结合推覆构造对侏罗系夏里组的保存比例,推测羌塘盆地保存的钾盐资源量约为11亿吨。该研究为进一步勘查古钾盐矿提供了明确的范围和方向。 相似文献
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我国已发现的钾盐矿床不能满足国民经济发展的需求,寻找新的大型钾盐矿床是一项紧迫的任务,塔里木盆地西部,在地史时期接受多次海侵,且盆地内广泛出露岩盐矿,是一有利的成矿区。古盐湖演化的最后阶段,浓度程度高的卤水汇聚到盆地的次级拗陷中,最后形成钾盐矿床,所以确定盐湖演化阶段盆地的次级拗陷位置对寻找钾盐矿至关重要。在详细查阅和消化前人资料的基础上,结合最近的野外考察认识和室内样品分析的数据,确立库车盆地的拜城—轮台地区和莎车盆地的喀什—和田、乌恰—阿克陶地区为找矿重点区域。 相似文献
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钾盐是我国的紧缺矿产资源之一,寻找钾盐资源尤其是古钾盐矿床对于我国具有重要的意义。但是由于钾盐易溶,在地表很少有成矿标志,所以加大了找矿的难度。通过论述地球化学方法在蒸发岩研究中的应用情况,指出地球化学方法在寻找钾盐的过程中有着重要的应用,其应用可以概括为:可以判断成盐古卤水的蒸发浓缩阶段和矿床的成矿阶段、揭示盐类矿床的物质来源及其沉积环境、划分蒸发岩的沉积旋回和重现古盐湖的演化过程以及分析成盐盆地的封闭蒸发条件和氧化还原性等。云南兰坪—思茅盆地是我国最具有找钾希望的区域,研究盆地内蒸发岩的地球化学特征对于在盆地内寻找钾盐矿床具有重要的指示意义。 相似文献
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紫色土的钾素形态转化 总被引：1，自引：0，他引：1
采用室内盆钵培养方法 ,研究侏罗纪蓬莱镇组 (J3P)、沙溪庙组 (J2 S)、遂宁组 (J3S)和白垩纪城墙岩群 (K1 C)紫色岩层发育土壤的钾素形态转化。结果表明 ,一年后 ,紫色土交换性钾增加 2 0mg.kg- 1 以上 ,非交换性钾增加 10 .5 8mg .kg- 1 ,结构钾减少了 31.5 6mg .kg- 1 。交换性钾、非交换性钾增加顺序分别为 :J3P >J3S >J2 S >K1 C及K1 C >J3P >J2 S >J3S ;结构钾降低的顺序为 :J3P >J3S >K1 C >J2 S。紫色土交换性钾、非交换性钾及结构钾互为消长有利于土壤源源不断地供给作物有效态钾素 ,一定程度弥补因作物带走的钾。 相似文献
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The influence of potassium on core and geodynamo evolution 总被引：3，自引：0，他引：3
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以察布查尔县1 191~2 656 m不同海拔草原土壤为研究对象,研究有机质（外加热法,10.18~74.3 3 mg·kg-1）、全氮（自动凯氏定氮仪,0.17~2.6 g·kg-1）、碱解氮（扩散法,14.9 7~198.72mg·kg-1）、磷元素（钼锑抗比色法,全磷：0.12~0.76 g·kg-1、速效磷：20.7 4~153.64 mg·kg-1）,钾元素（火焰光度计法,全钾：9.81~18.64 g·kg-1、速效钾：659.05~1 001.45 mg·kg-1）含量垂直分布特征。结果表明碳、氮、磷、钾均随土层深度的增加而降低;除钾元素外碳、氮、磷随海拔高度的增加而上升;相关性分析结果显示,0~20 cm土层中,海拔高度与碱解氮呈正极显著性相关（p < 0.05,R=0.838**）,与土壤有机、全氮呈正显著性相关（p < 0.05,R=0.831*、R=0.751*）;有机质与碱解氮呈正极显著性相关（p < 0.05,R=0.988**）,与全磷呈正显著性相关（p < 0.05,R=0.726*）,20~40 cm土层中,海拔高度与有机质、碱解氮、全氮、全磷呈正相关,与速效磷、速效钾、全钾呈负相关;有机质与碱解氮、全氮成正极显著性相关（p < 0.05,R=0.867**、R=0.970**）,碱解氮与全氮呈正极显著相关（p < 0.05,R=0.914**）,40~60 cm土层中,海拔高度与有机质、碱解氮、全磷呈正相关,与速效磷、全磷、速效钾、全钾呈负相关;有机质与碱解氮、全氮呈正极显著性相关（p < 0.05,R=0.884**、R=0.966**）,与速效磷、全钾呈正相关,与全磷、速效钾呈负相关;碱解氮与全氮呈正极显著性相关（p < 0.05,R=0.952**）。 相似文献
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When potassium (K+) fertilizers are applied to soil, K+ is subject to displacement through the soil profile. More generally, the application of K+ fertilizers to sandy soils with low clay content and small buffer capacity, in which K+ does not interact strongly with the soil matrix, results in localized increases in K+ concentration in the soil solution. Losses of K+ depend on the concentration of calcium (Ca2+) as a competing ion in the leaching water and the amount of water that passes through the soil. In this study, we examined the adsorption and movement of applied K+ in columns of sandy soil. Glass tubes, 4.8 cm in diameter and 40 cm in length, were packed with either native soil or Ca2+-saturated soil. The resulting 10-cm-long column of soil had a bulk density of 1.65 g cm−3. Native soil was leached with distilled water and CaCl2 solutions of various concentrations. In the Ca2+-saturated soil, a pulse of K+ was leached with CaCl2 solutions of various concentrations or distilled water. Increasing the CaCl2 concentration from 3 to 15 mm resulted in earlier breakthrough, a higher peak concentration of K+, and greater amounts of leached K+. The breakthrough curve for K+, when leached with distilled water, showed very low concentrations and was more delayed than the other treatments. In Ca2+-saturated soil, the amount of K+ leached increased as Ca2+ concentration increased, with up to 54% of the added pulse K+ being removed from 10 pore volumes (Pv) (387 mm) of 15 mm CaCl2. The presence of Ca2+ in irrigation water and soil minerals able to release Ca2+ is important in determining the amount of K+ leached from soils. Large amounts of K+ are leached from soils in areas where crops are irrigated with water that contains significant concentrations of Ca2+ and other cations. 相似文献
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Changes in the relationship between soil soluble ions and rainfall were studied on hillslopes at seven research sites that represent four climatic regions: Mediterranean, semi-arid, mildly arid and arid. At each site, soil samples were taken in several seasons and the ratio between the Na+ plus K+ content and the Ca2+ plus Mg2+ content (sodium and potassium adsorption RATIO=SPAR) was determined. In general, SPAR increased with increasing aridity except for the most arid site in which the soil contains a gypsic layer. The relationship between SPAR and rainfall was non-linear. An abiotic threshold, characterized by a sharp change in the SPAR, was found around the 200 mm isohyet: sites that receive less than 200 mm annual rainfall showed significantly higher SPAR than those that receive more than 200 mm, where SPAR was very low. 相似文献
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该文根据相关研究资料，详细探讨了青海昆特位和马海盐湖区钾镁盐矿床固体矿的成因、物质成份、矿床的规模以及矿床的沉积特征，并且对两地区固体矿形成模式作了研究。 相似文献
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依据青海昆特依、马海两矿区固体钾镁盐矿物质成份、矿床规模、矿石品位、埋藏深度等地质条件和矿区自然经济地理条件、勘查程度及开发现状，进行了两矿区开发的经济远景评价。 相似文献
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A field trial on 3-year-old Prosopis alba growing on pH 8.5 soils in Argentina was conducted to identify mineral nutrients that were most limiting growth and to determine correlations among these nutrients. As applications of nutrients such as Zn, Cu and P would be soon rendered unavailable due to the high pH, combinations of elemental S to decrease the pH were examined along with macro and micronutrient soil additions. Thirty trees were selected with stem diameters ranging from 2.8 to 4.5 cm and divided into five treatments in a completely randomized design with 1 tree per replicate. The treatments were: (1) control, (2) addition of elemental S to lower the pH, (3) addition of S and triple superphosphate (P), (4) addition of S, P and a complete blend of micronutrients and (5) addition of S, P, micronutrients and K and Mg. Biomass increases were estimated using regression equations on stem diameter increases. A small non-significant decrease in pH of about 0.3 pH was obtained in the treatments with S, except for treatment which contained micronutrients in the form of strong base oxides. There was a significant increase in electrical conductivity due to the oxidation of the S. The best treatment containing S, P and micronutrients had a 42% increase significant biomass increase over the control. Growth was positively correlated with leaf levels (decreasing order of significance) of K, S, P, and Zn and negatively correlated with leaf Na and Ca. The leaf K, which had the highest positive correlation with growth, was highly significantly positively correlated with leaf S, P, N, and Zn and highly significantly but negatively correlated with leaf Ca, Mg and Mn. Leaf N was very highly correlated with leaf Zn, S and P concentrations. Indian workers have found that 20 years after establishment Prosopis juliflora changed the soil pH from 10.4 to 8.0. Since trees on 10 m×10 m spacings are suggested to be ultimate climax density for these ecosystems, apparently it will only necessary to add inexpensive small quantities of elemental S, Zn and K directly around 100 small trees ha−1 to effect a major soil reclamation over the entire ha. 相似文献
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