Seasonal variation of the microbially regulated buffering capacity at sediment-water interfaces in a freshwater lake     

Maja A. Lazzaretti-Ulmer  Kurt W. Hanselmann 《Aquatic Sciences - Research Across Boundaries》1999,61(1):59-74

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黄骅坳陷中北区深部储层物性影响因素分析   总被引：14，自引：5，他引：9  

游俊  郑浚茂 《现代地质》1999,(3)

通过对黄骅坳陷中北区的研究认为, 影响该地区深部储层物性的因素主要有沉积环境和沉积相、成岩作用和深部地层异常超压的形成与分布等, 其中成岩作用中的胶结作用（ 主要为硅质胶结和铁白云石胶结） 是致使深层孔隙度降低的主要原因, 酸性水的溶解作用是产生大量次生孔隙的重要因素, 深部异常压力带的存在是次生孔隙得以保存的重要条件  相似文献   

Factors controlling the distribution of transitional metal elements in marine hydrogenic ferromanganese crusts     

JIANG Xuejun）  ）*  YAO De）  LIN Xuehui）    ZHAI Shikui）） College of Geoscience  Ocean University of China  Qingdao  P. R. China ） Qingdao Institute of Marine Geology  China Geological Survey  P. R. China ） College of Georesources  Environmental Engineering  Sh  ong University of Technology  Zibo  P. R. China 《中国海洋大学学报(英文版)》2009,8(1):57-64

A series of selective dissolution experiments were conducted on the hydrogenic ferromanganese crusts collected near Line Island to study the geochemistry of Mn, Fe, Cu, Co, Ni and Ti. Despite of the fact that the very close intergrowth between amorphous ferric oxyhydroxides and δ-MnO2 exists in the hydrogenic ferromanganese crusts, there is no isomorphous substitution between iron and manganese. This is because the two elements in oxides have different crystal chemistry and geochemistry, such assertion bein...  相似文献   

赣南小流域水体中稀土元素的地球化学特征   总被引：1，自引：0，他引：1  

罗建美  季宏兵  霍永伟 《地球学报》2007,28(5):438-445

本文以赣南小流域水体为研究对象,利用VG Axiom高分辨多接受双聚焦等离子体质谱仪测定了水体中溶解态稀土元素(DREE)的含量,分析了水体中DREE的分布分异机制,并探讨了稀土元素(REE)产生分异的原因.结果表明,赣南所有的采样区水体中Ce都表现为负异常,说明其在风化壳中少活化.受自然风化作用控制为主的水体相对于页岩除Ce亏损、Eu富集外产生的分异很小,其中Eu的正异常源于Eu富集矿物的优先溶解;蒸发盐矿影响下的水体相对于自然作用为主的水体DREE没有发生明显分异;受稀土矿影响的水体中重稀土元素(HREE)富集、Eu负异常的分布模式继承了稀土矿区风化壳的特征;赣州市下游干流水体中中稀土元素(MREE)富集、Eu负异常的分布模式主要是人为影响的结果.  相似文献   

青海马海盐湖低品位固体钾矿室内溶矿实验研究          下载免费PDF全文

张宇萌  赵艳军  胡宇飞 《岩石矿物学杂志》2023,42(5):745-756

柴达木盆地马海盐湖浅部赋存有储量可观的低品位固体钾盐资源,通过水溶开采即固液转化的方法为企业10万吨/年的钾肥生产提供了资源保障。随着水溶开采工作的持续进行,目前马海钾矿区北部浅部固体钾矿的品位进一步降低,给盐田和选矿工艺的调整带来极大挑战。为使这部分资源得以充分利用,本文以马海盐湖钻孔9-13和9-3附近埋深0～3m的固体钾矿样品为研究对象,系统开展了室内溶矿模拟实验。实验结果表明:(1)在固体钾矿KCl品位较低时,适当提高溶剂的波美度,有利于K⁺的溶出,提高溶出液中K⁺的浓度。(2)溶剂中Na⁺的浓度太低会溶解盐层骨架,而Na⁺的浓度太高会导致结盐,生产中应根据钾矿层的实际情况,以满足溶出液K⁺浓度含量达标为准调整溶剂的波美度。(3)随着马海矿区固体钾矿品位持续降低,当K⁺的浓度达到盐田生产要求时,钠盐池卤水中Na⁺的浓度会明显增加,卤水中SO₄^2-相对浓度也相应增加,钠盐池阶段析出的石...  相似文献   

多孔纤维矿物在氨基酸水溶液中的溶解性及其生物持久性研究   总被引：3，自引：0，他引：3  

李国武  董发勤  彭同江  万朴 《岩石矿物学杂志》2000,19(3):220-225

在模拟人体温度３７℃条件下,进行多孔纤维矿物粉尘与氨基酸作用的实验研究。在７２ｈ内溶解过程中ｐＨ值和电导率的变化结果表明,多孔纤维矿物在氨基酸中发生的溶解作用与到的性质有关,酸性氨基酸对矿物的溶解能力最强,中性次之,碱性最弱。其溶解过程在前８ｈ以内较强,以后趋于平缓,纤维矿物在氨基酸中的溶解程度从小到大为：斜发沸石－坡缕石、海泡石－蛇纹石,说明斜发沸石有较强的耐蚀能力,其生物持久性较高,而蛇纹石石  相似文献   

外掺Cl对磷酸镁水泥离子溶出和孔结构的影响          下载免费PDF全文

董飞  周永全  董金美  文静 《盐湖研究》2021,29(2):20-28

通过测试不同Cl-(NaCl)掺量磷酸镁水泥(MPC)浸取液中离子浓度及MPC硬化体的孔结构和吸水率,研究了Cl-掺量和浸取时间对MPC硬化体平均孔径、孔隙率、孔径分布、孔体积分布、吸水率、MPC浸取液中Cl-、Na+、OH-、Mg2+、PO43-和K+浓度的影响,结果表明外掺Cl-对MPC孔结构、离子溶出及吸水率有显...  相似文献   

Fabrics,facies control and diagenesis of lacustrine ooids and associated grains from the Upper Triassic,southwest England     

P. G. Milroy  V. P. Wright 《Geological Journal》2002,37(1):35-53

Petrographic analysis of ooids from the Upper Triassic (Mercia Mudstone Group) of southwest England provides an opportunity to assess in detail the origins, transport pathways and diagenesis of an ancient oolite. The Clevedon Oolite is dolomitized and contains a variety of dissolved ooids (oomoulds) and associated grains. The oomoulds occur in well‐sorted, planar and cross‐stratified grainstones, packstones, sandstones and conglomerates associated with shoreface, intershoal, foreshore, beachrock and littoral strandplain deposits. The ooids grew in suspension in the shoreface zone and developed a radial aragonite microstructure. The ooids grew to 0.80 mm in diameter, after which they fractured or ceased growing. Broken grains deposited on or near mobile shoals were rapidly recoated, while other grains, deposited in less agitated, intershoal and lower foreshore areas, were micritized or microbially bound into grapestone aggregates. Locally peloids, intraclasts, quartz grains and micritized grains from intershoal areas supplied nuclei for ooids on nearby shoals. Grains deposited in foreshore areas were rapidly cemented into beachrock and reworked into conglomerates. Soon after deposition, the ooids were subjected to widespread aragonite dissolution followed by dolomitization. The lack of pre‐dolomitization calcite, together with the abundance of early (pre‐compaction) dolospar cements and fabric‐selective dolomitization of micritic fabrics, suggest aragonite dissolution by dolomitizing fluids. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献