Composition and assemblage characteristics of magnetic minerals in layer S<Subscript>5-1</Subscript> of Xifeng and Duanjiapo sections     

Jia?RongfenEmail author  Peng?Xianzhi  Zhou?Zheng  Liu?Dehan  Wang?Guanxin  Wang?Deqiang 《中国地球化学学报》2004,23(3):197-206

Relatively strongly magnetic fine components (< 30μm, XS-4J and DS-4J) which are most environmentally sensitive were separated from layer S_5-1 in the Xifeng and Duanjiapo loess sections and analyzed by MPV-3 for their morphometric characteristics and reflectance, SEM-ESD for their element contents and XRD for their mineral phases, respectively. The results showed that minerals in both samples are dominated by detrial Fe-Ti oxides of aeolian origin. In sample XS-4J the reflectance and iron contents of magnetic minerals are usually high. In addition to magnetite (Fe₃O₄), maghemite (γFe₂O₃) and hematite (Fe₂O₃), some Fe-high oxide (72.25 wt%–86.67 wt%), ilmenite (FeTiO₃), and magnetite-ulvöspinel [Fe(FeCr)O₄, Fe (FeNi)O₄] were also detected. In sample DS-4J obvious negative linear correlations were found between Ti and Fe, and the contents of Mn, Si, Al and Ca are usually high and the minerals are dominated by magnetite (maghemite), goethite (FeOOH) and limonite (containing Si and OH). In addition, the signs of corrosion of magnetic minerals and newly crystallized magnetite (maghemite) were recognized. Differences in the composition and assemblage characteristics of magnetite minerals between XS and DS reflect significant differences in source rocks and preserving conditions.  相似文献   

Use of microelectrodes for electrochemical measurement of nitric oxide in natural seawater     

张正斌 邢磊蔡卫君  任春艳姜立庆 《中国海洋湖沼学报》2004,22(4):373-380

In this paper, the application of a homemade Nation and Co(Salen) modified platinum microelectrode and an ISO-NOPMC microsensor (World Precision Instruments, USA ) to measure nitric oxide in natural seawater is reported. These two microelectrodes are suitable for the measurement. In natural seawater, the sensitivity and stability of the ISO-NOPMC microsensor are higher than that of the homemade Nation and Co(Salen) modified platinum microelectrode.  相似文献   

原子吸收分光光度法快速测定铬铁矿中钙、镁、锰   总被引：2，自引：0，他引：2  

熊艳 《安徽地质》2006,16(4):270-272

通过在标液中加入相应的Sr来消除离子干扰,采用原子吸收分光光度法快速测定CaO、MgO、MnO的含量,方法经国家标准物质验证,其RSD<2%(n=6)。其结果与标准值相符。方法达到了准确、简便、快速、实用性强。  相似文献   

酒石酸异构体对EDTA间接滴定法测定矿石中三氧化二铝的影响     

杨载明  唐晓玲 《岩矿测试》2009,28(1):75-76

应用EDTA间接滴定法测定铝土矿、高岭土、黏土等矿石中的三氧化二铝,试验了不同种类的酒石酸掩蔽钛对三氧化二铝测定结果的影响。建议选择左旋体或右旋体酒石酸作掩蔽剂,尽量不要选择内消旋体酒石酸,更不能选择外消旋体酒石酸。采用酒石酸钾钠作掩蔽剂,三氧化二铝的测定结果良好,方法快速、简便。  相似文献   

土壤中三氧化二铝测定结果的不确定度评定     

陈志清  曹静  梅祖明 《岩矿测试》2009,28(6):583-586

讨论了影响三氧化二铝测定结果不确定度的各种因素,并评定了土壤样品中测定三氧化二铝结果的不确定度。采用EDTA络合、氟化钾置换、乙酸锌溶液滴定的测定方法,当三氧化二铝的含量为15.03%时,其扩展不确定度U=0.20%(Urel=1.4%,k=2)。  相似文献   

Searching for ancient gold mines in Filippoi area,Macedonia, Greece,using Worldview-2 satellite imagery     

Dimitrios Oikonomidis  Michael Vavelidis  Vasilios Melfos  Mariam Artashova 《国际地球制图》2017,32(1):87-96

The study area is located near the town of Filippoi, north of the city of Kavala in northern Greece, known from ancient times for its rich gold mines, situated inside hydrothermal alteration zones (Fe–Mn oxide minerals). A Very High-Resolution (0.5 m pixel size) image of Worldview-2 satellite was digitally enhanced, yielding target areas of potential ore existence and lineaments. Ground-truth that followed digital image processing, revealed abandoned ancient mines, slags and ore occurrences. Also, a number of lineaments delineated on the satellite image were verified as faults.  相似文献   

Types and genesis of manganese oxide ores in Guangxi, Southwest China     

刘腾飞 《中国地球化学学报》1999,18(1):87-96

Systematic studies are diven to the genesis and spatial distribution of manganese oxide deposits in Guangxi,Southwest China.The deposits are classified as 3 types and 7 subtypes among which the karst depression type is regionally characteristic an of reat potential.A genetic model is presented for the mineralization on the basis of proto-rock,tectonic background,topographic features and climatic and hydrogeological conditions.  相似文献   

西昆仑山甜水海钻孔氧化铁指标的R／S分析及其意义   总被引：17，自引：0，他引：17  

周厚云  李世杰 《冰川冻土》1999,21(2):136-140

运用Ｒ／Ｓ分析法,对经过等时处理的甜水海钻孔氧化铁３项指标ＦｅＯ、Ｆｅ２Ｏ３及其比值ＦｅＯ／Ｆｅ２Ｏ３进行了分析计算,其指标都存在明显的Ｈｕｒｓｔ现象,Ｈｕｒｓｔ指数Ｈ分别为：Ｆｅ２Ｏ３为０．７６,ＦｅＯ为０．８５,ＦｅＯ／Ｆｅ２Ｏ３为０．６５,它们都大于０．５。反映了该地区过去２０多万年来气候环境变化存在持续性。３者Ｈｕｒｓｔ指数存在差异的原因目前还不清楚,可能说明它们反映气候环境演化持续性强度  相似文献   

水声学方法对黄河口水下底坡失稳现象研究     

阎通  李萍  杨作升  庞重光 《中国海洋大学学报(自然科学版)》1999,(2)

对黄河三角洲东北部地区的高分辨率水声学资料进行了综合研究。根据所记录的破坏土体变形程度、运动产生的平面形状和地貌特征形态,对土体失稳过程进行分类：浅表土体变形、塌陷凹坑、滑坡和沉积物重力流。结果表明：（１）浅表土体形变的变形程度最低,出现在研究区斜坡上部平滑海底,主要为绳网状泄水构造和表层拉张裂隙。（２）塌陷凹坑在研究区内广泛出现,是局部土体液化后发生了垂直沉降的结果。（３）滑坡多发生在水下斜坡的中上部,由弧形塌陷区、狭窄的冲沟通道和负地形沉积物堆积区组成。滑坡陡坎后缘发现拉张裂隙。（４）沉积物重力流是土体发生变形程度最大,搬运距离最长的土体破坏变形形式。局部区域多次受到沉积物重力流切割和充填作用。  相似文献   

云南维西大宝山铜矿地质特征及矿石中Ag与Cu关系探讨     

巩鑫 《地质与勘探》2020,56(1):49-58

云南维西大宝山铜矿区位于青藏高原东南缘,哀牢山-金沙江构造带西北部雪龙山成矿带中,是典型的中低温热液矿床。矿区主要包括望香台及滑石板矿段,根据矿床、矿体特征及详尽的镜下观察,将矿石类型划分为氧化矿、硫化矿及混合矿。氧化矿主要包括孔雀石及蓝铜矿,多分布在望香台矿段中浅部,是辉铜矿次生氧化富集作用的结果,出露形式多以混合矿产出;硫化矿主要包括辉铜矿及黄铜矿,且独立组成不同的矿物组合类型,分别为望香台矿段、滑石板矿段的主要矿石矿物。不同的矿石组合类型所含矿物种类、矿石结构构造不尽相同。通过对不同样品进行化学分析测试,发现在硫化矿辉铜矿等矿物组合中,Cu品位越高,相应Ag品位越高,存在一定的线性关系;而在硫化矿黄铜矿矿体中,Ag含量与Cu品位无相应关系;混合矿(辉铜矿、孔雀石及蓝铜矿)中此类关系更加显著。此外,辉铜矿、孔雀石、蓝铜矿单矿物矿石及混合矿矿石中含有硫砷铜银矿、深红银矿、雌黄及雄黄等伴生矿物,而黄铜矿中矿物种类较为单一。综合矿区地质特征、矿体分布特征、矿物组合类型认为,矿区中辉铜矿、孔雀石、蓝铜矿等组合类型为含银矿物的主要载体。  相似文献