电感耦合等离子体发射光谱法测定键合用硅铝丝中硅铁铜

采用电感耦合等离子体发射光谱法测定硅铝丝（Al—1％Si）中Si及杂质元素Fe和Cu。确定了最少取样量和样品溶解方法，优化了元素分析谱线和仪器的测量条件。实验表明，方法的加标回收率为99％～1叭％，相对标准偏差（n=6）低于1．4％，Si、Fe、Cu的检出限分别为8．5、1．0和0．4μg／L。该方法应用于快速测定键合硅铝丝中的各种元素，结果满意。     

微波消解-等离子体发射光谱法同时测定水中硅铁钠

讨论使用电感耦合等离子体发射光谱法测定水样中si、Fe、Na时，四种水样前处理方法对测试结果的影响。提出采用HNO3^-HF体系微波消解、H3BO3掩蔽HF的方法前处理水样，用等离子体发射光谱法可同时准确快速地测定水中Si、Fe、Na三种元素的含量。5次测定的相对标准偏差小于4％，加标回收率为89．2％-106％。     

浅析莱芜接触交代-热液铁矿的双交代渗滤作用

莱芜接触交代-热液铁矿赋存于奥陶系马家沟组碳酸盐岩与燕山晚期闪长岩的接触带及其附近.通过对各矿床有益有害组分分析,以及对成矿母岩、围岩岩石化学特征、双交代渗滤作用和围岩蚀变类型等研究,总结出"三位一体"成矿模式,进而探讨了矿体的空间分布规律及其找矿意义.     

新疆西天山智博铁矿床地球化学及同位素特征

智博铁矿位于新疆西天山阿吾拉勒铁成矿带东段,矿体以层状、似层状、透镜状产出于下石炭统大哈拉军山组玄武质安山岩中。智博铁矿成矿作用主要划分为岩(矿)浆期和热液期2个成矿期次,包括3个成矿阶段:磁铁矿+透辉石阶段、磁铁矿+绿帘石+钾长石阶段和石英+硫化物+碳酸盐阶段。智博铁矿地球化学特征表明,其成矿构造背景为早石炭世南天山洋向伊犁板块俯冲形成的岛弧环境;火山岩与磁铁矿石具有相同的物质来源,均来源于受俯冲带流体交代的亏损地幔楔部分熔融形成的玄武质岩浆。智博铁矿为岩浆(主要)-热液(次要)复合型矿床,受俯冲流体交代的亏损地幔楔部分熔融形成富铁的玄武质岩浆,岩浆沿深大断裂上侵形成早期火山岩,上侵过程中由于物理化学条件的改变在不混溶作用下形成铁矿浆,铁矿浆侵入早期火山岩地层形成岩浆期磁铁矿体;后期富铁的岩浆或矿浆热液使围岩发生矿化与蚀变,形成热液期磁铁矿体。     

Extractable and total Fe and Mn contents of three sand dune soils in NW Nigeria

The profile distribution of total, diethylene triamine penta-acetic acid (DTPA)- and 0·1 HCl-extractable Fe and Mn were determined in 12 pedons formed on three contiguous sand dunes in the semi-arid savanna of Nigeria. The total Fe and Mn contents varied from 100 to 3750 and 40 to 11,375 μg g⁻¹, respectively. Values of 0·1 HCl-extractable Fe and Mn varied from 8·0 to 123 and 1·5 to 43·5 μg g⁻¹, respectively. The corresponding values of DTPA-extractable Fe and Mn were 4·5 to 16·0 and 1·0 to 38·8 μg g⁻¹. Total Fe and Mn correlated significantly with clay in nearly all the dunes (p≤ 0·01) but were not significantly correlated with organic matter. The 0·1 HCl-extractable Mn had a positive significant correlation with soil pH (r= 0·58*) in Illela dunes but a negative significant correlation with pH in the Sangiwa dunes (r= −0·75***). The values of extractable Fe and Mn in the sand dune soils are above the critical limits reported in other literature, thus deficiencies of these micronutrients do not pose a problem to crop production in the study area.     

鄂西宁乡式铁矿分布层位岩相特征与成因探讨

鄂西宁乡式铁矿分布广、规模大,尤以普遍发育赤铁矿鲕粒而独具特色。并且它一般赋存于加里东运动后第一个海浸沉积序列中由碎屑岩向碳酸盐岩过渡的层位,岩相古地理环境有明显的控制作用。本文铁矿层中赤铁矿鲕粒类型之繁多,结构之复杂,安全可与碳酸盐鲕粒相提并论,其成因亦非常相似,均为强烈搅动环境中机械沉积的产物。经波浪和潮汐水流的再次搬运富集。最后定们于中等一弱动荡环境或相地低凹摈滨相上部。     

塔尔塔格铁矿床——新疆阿吾拉勒铁成矿带内首例IOA型铁矿床的厘定及意义

塔尔塔格铁矿是新疆西天山阿吾拉勒海相火山岩型铁成矿带内的一处中型铁矿床,其铁矿体呈透镜状产于粗安玢岩内顶部,在揭示海相火山岩中铁矿床与侵入岩关系方面具有重要意义。该铁矿床发育典型的磁铁矿 磷灰石组合,基本不含硫化物,矿石以似斑状、浸染状、球粒状和晶洞等构造类型为特色,磁铁矿内发育由条带状或叶片状钛铁矿和钛氧化物构成的出溶结构,并有少量的榍石、钍石、萤石等副矿物与之共生,矿床地质特征表明该矿床为典型的与富碱、中性侵入岩有关的IOA（iron oxide apatite）型铁矿床。该矿床围岩英安岩、赋矿粗安玢岩与成矿后正长花岗岩的锆石SHRIMP U Pb同位素加权平均年龄分别为311. 3±1. 4 Ma、304. 7±2. 9 Ma和301. 1±2. 8 Ma,铁矿石样品中与磁铁矿共生的榍石的LA ICP MS U Pb同位素加权平均年龄为302. 3±4. 0 Ma和303. 7±4. 2 Ma,成岩成矿年龄高度吻合,进一步确定其在晚石炭世晚期成矿。本文根据地质特征认为该矿床矿石是由粗安玢岩顶部富铁挥发分聚集而形成的,并初步提出“超浅成侵入岩顶部富挥发分囊体”成矿模型,即富碱、中性岩体超浅成侵位导致挥发分在岩体顶部迅速聚集形成多处富铁和挥发分的囊体,岩体冷凝固结的同时磁铁矿快速结晶成矿。塔尔塔格“IOA型”型铁矿的成因厘定,不仅表明海相火山岩型铁矿与IOA型铁矿可能存在成因联系,还暗示了海相火山岩型铁成矿带内具有寻找IOA型铁矿的潜力。     

Geochemical characterization of Archaean amphibolites from the eastern part of Anshan–Benxi iron producing area,northeastern China: implication for tectonic setting of BIFs

The Anshan–Benxi iron producing area, which is located at the northeastern margin of the North China Craton, is the main distribution area of Archaean BIFs in China. In their eastern part, including the Gongchangling and Waitoushan deposits, BIFs mainly are hosted in the Archaean middle Anshan Group. Amphibolites are widely distributed in the iron‐bearing rock series, reflecting the tectonic setting of BIFs. Amphibolites not only have MORB‐like compositional characteristics, but also have island arc‐like ones, and they are consistent with back‐arc basin basalts (BABB). In the study area, the protolith of amphibolites belongs to Okinawa‐type BABB; it indicates that tectonic setting of BIFs is the intra‐continental back‐arc basin. In the study area, the formation of sedimentary basins for BIFs had been associated with oceanic plate subduction. Amphibolites from Gongchangling deposit are characterized by relative enrichments in LILE and LREE, and depletions in HFSE. This indicates that they had a relatively large influence of subduction in their formation. Amphibolites from Waitoushan deposit are characterized by relative enrichments in LILE without conspicuous depletions in HFSE, indicating relatively low subduction rates. Copyright © 2015 John Wiley & Sons, Ltd.     

Iron and phosphorus effects on the growth of Cryptomonas sp. (Cryptophyceae) and their availability in sediments from the Pearl River Estuary, China

Based on lab-culture experiments analyzing limitation and combination of iron and phosphorus on the growth of Cryptomonas sp. (Cryptophyceae), and the study of accumulation and release of Fe-bound P in sediment cores collected from the marine region of the Pearl River Estuary, China, reasons for the high frequency of phytoplankton bloom therein are discussed. Results show that the combined effect of Fe and P can obviously accelerate algal development, and the optimum culture conditions maintaining maximum growth rate are 0.05 μM Fe and 50 μM P. Cellular contents of Fe and P is consistent and the P:Fe molar ratio is 159:1. The optimum range of the P:Fe molar ratio in culture experiments for cell incubation is 500–1400. The vertical trends of total Fe and total P variations in sediments are parallel. Fe-bound P is the main species of inorganic sedimentary P. Through continuous leaching with agitation, 34–80% of exchangeable P and 4–23% of exchangeable Fe are concurrently released from the surficial sediments. This is a possible way by which nutrients are made available to phytoplankton. These factors might be responsible for a high frequency of harmful algal blooms in the Pearl River Estuary.     

河南窑场铁矿床成因矿物学研究及其地质意义

窑场铁矿床位于河南鲁山地区,大地构造位置属于华北陆块南缘,控矿地层为太华群铁山岭组,主要矿体共有两个,主要有辉石铁英岩和角闪石铁英岩组成,夹有少量的黑云角闪片岩、大理岩和花岗质混合岩,主要的矿石矿物为磁铁矿(30%～35%),少量赤铁矿(5%)和镜铁矿(3%)。脉石矿物有石英、角闪石、辉石、石榴子石等。围岩的组成包括黑云辉石岩、黑云角闪岩、黑云角闪片岩、黑云片岩、角闪黑云变粒岩、大理岩及少量的花岗质混合岩。矿石中的角闪石均属于镁角闪石,辉石有富铁透辉石、斜铁辉石,磁铁矿以纯磁铁矿为特征;围岩中的角闪石属于镁角闪石和纯镁闪石,辉石主要为透辉石,黑云母为镁质黑云母,伴有少量金云母,石榴子石以铁铝榴石为主,含有镁铝榴石、钙铝榴石分子。化学成分分析显示本区的变质相达角闪岩相,估算其变质的压力范围为0.36GPa～0.74GPa。与典型华北陆块前寒武纪铁矿床对比,窑场铁矿床的矿物组合、变质等级以及沉积相类型均与新太古代的条带状铁建造相似。磁铁矿高Ni、低Co的特点表明其成矿来源与深部物质有关。