磷、铁营养盐的交互作用对隐藻(Cryptomonas sp.)生长影响的初步研究

利用正交实验设计方法,初步研究和探讨了磷、铁营养盐交互作用对隐藻生长的影响。结果表明,磷、铁营养盐的交互作用(P×Fe)的影响是极其显著的,得出隐藻合适生长铁浓度范围为50 nmol/L~1μmol/L,隐藻生长的培养液最优组合为10μmol/L磷浓度和100 nmol/L铁浓度。     

松辽盆地南部片钠铝石形成与碎屑长石的成因联系

含片钠铝石砂岩通常以富长石类型为主(岩屑长石砂岩,长石岩屑砂岩,长石砂岩)。为揭示片钠铝石与长石之间的主要赋存关系及长石在片钠铝石形成过程中所做的贡献,通过偏光显微镜、扫描电镜及阴极发光等镜下观察方法对松辽盆地南部红岗地区含片钠铝石砂岩进行了岩石学系统研究。本区片钠铝石主要以充填孔隙及交代颗粒的形式产出,其中片钠铝石交代斜长石的现象明显多于交代钾长石,片钠铝石交代斜长石初期优先沿其双晶缝向内生长,有些甚至完全交代斜长石而呈现交代假象。整体上片钠铝石含量与长石含量呈负相关关系。长石的溶蚀溶解为片钠铝石的形成提供Na+、Al 3+,由于各类长石的热力学性质存在差异,钾长石发生溶蚀溶解的速率及程度会明显低于斜长石,因此斜长石对形成片钠铝石的离子贡献大于钾长石。     

新疆若羌喀腊大湾铁矿床辉钼矿Re-Os定年及成因

喀腊大湾铁矿是近年来在阿尔金地区发现的超大型铁矿,目前控制储量近亿吨,且该铁矿具有品位高,低硫低磷等特点。由于矿床围岩的特殊性,该矿床的成因一直存在较大争议。利用Re-Os同位素定年方法,对喀腊大湾矿体中的5件辉钼矿样品进行了成矿时代测定,获得辉钼矿Re-Os同位素模式年龄为490±11Ma,等时线年龄为481.9±7.6Ma。二者在误差范围内基本一致。该年龄与成矿相关岩体的SHRIMP锆石U-Pb年龄488±5Ma及479±4Ma吻合,且发现的矿体附近都有闪长岩体出露,表明成岩和成矿关系密切。结合岩石学、矿物学及年代学特征,认为喀腊大湾铁矿为矽卡岩矿床。     

海水中铁的几种形态对海生小球藻生长的影响

通过实验室一次性培养 ,研究不同形态的铁 :Fe3 + ,Fe2 + ,Fe3 + - EDTA,Fe2 + - EDTA以及胶体水合氧化铁在不同条件下对海生小球藻 (Chlorella vulgaris)生长的影响。实验结果表明 ,铁对小球藻生长影响的主要生物活性形式是有机络合态铁和胶体水合氧化铁 ,光诱导还原态 Fe2 + 也很重要。它们都积极促进了藻类的生长繁殖 ,其中 EDTA与铁离子结合的动力学过程并不明显影响藻类吸收铁。小球藻相对生长率的提高和叶绿素 A(Chl.a)的增加取决于铁的总量及其转变为可利用状态的速率 *和藻类的有效吸收。在不同的培养体系中 ,常量营养盐 N、P与 Fe的缺乏对藻类生长起着交互限制作用 ,其中缺 P比缺 N更能减少 EDTA络合铁对小球藻生长繁殖的促进作用。     

Coupled asteroid impacts and banded iron-formations,Fortescue and Hamersley Groups,Pilbara, Western Australia

Asteroid impact spherule layers and tsunami deposits underlying banded iron-formations in the Fortescue and Hamersley Groups have been further investigated to test their potential stratigraphic relationships. This work has included new observations related to the ca 2.63 Ga Jeerinah Impact Layer (JIL) and impact spherules associated with the 4th Shale-Macroband of the Dales Gorge Iron Member (DGS4) of the Brockman Iron Formation. A unit of impact spherules (microkrystite) correlated with the ca 2.63 Ga JIL is observed within a >100 m-thick fragmental-intraclast breccia pile in drill cores near Roy Hill. The sequence represents significant thickening of the impact/tsunami unit relative to the JIL type section at Hesta, as well as relative to the 20–30 m-thick ca 2.63 Ga Carawine Dolomite spherule-bearing mega-breccia. The ca 2.48 Ga-old Dales Gorge Member of the Brockman Iron Formation is underlain by an ?0.5 m-thick rip-up clast breccia located at the top of the ca 2.50 Ga Mt McRae Shale, and is interpreted as a tsunami deposit. We suggest that the presence of impact ejecta and tsunami units stratigraphically beneath a number of banded iron-formations, and units of ferruginous shale in the Pilbara and South Africa may result from a genetic relationship. For example, it could be that under Archean atmospheric conditions, mafic volcanism triggered by large asteroid impacts enriched the oceans in soluble FeO. If so, seasonal microbial and/or photolytic oxidation to ferric oxide could have caused precipitation of Fe₂O₃ and silica. In view of the possible occurrence of depositional gaps and paraconformities between impact ejecta units and overlying ferruginous sediments, these relationships require further testing by isotopic age studies.     

山东省兰陵县草主山矿区铁矿床地质特征和找矿远景分析

兰陵县草主山矿区属苍峄铁矿带一部分,区内赋存有全隐伏的"鞍山式"铁矿床,经勘查共圈定了南北2个主矿带,5个矿体。矿体赋存于泰山岩群山草峪组中,其形态受基底褶皱控制,具有平行延伸的特点,经过以往地质勘查工作,基本查明了-800m以浅矿体的产出位置、形态、产状、规模、分布、厚度、矿石质量等。矿体沿走向倾向尚未封闭,有继续延伸的趋势,并且矿石品位和矿体厚度未有减弱趋势,由此可得结论其-800m以深仍有很大的找矿前景,满足深部找矿的要求,总结其成矿规律、找矿标志,建立找矿模式,可为进一步勘查提供可靠的地质参考依据。     

王水溶样-火焰原子吸收光谱法直接测定高品位金矿石的金量

原子吸收光谱法(AAS)应用于高品位金矿石中金的测定,有效地解决了火试金重量法和氰醌容量法等分析方法有毒化学试剂用量大、测试条件局限性大等诸多问题。泡沫富集-火焰原子吸收光谱法(泡沫富集-FAAS法)就能够测定金品位达到500μg/g的金矿石,但该方法在常规FAAS方法基础上增加了滤渣分离、滤液稀释及泡沫灰化、复溶等过程,由于操作环节的增多,分析效率不高,且引入测量误差的机率随之加大。本文建立了一种高品位金的快速分析方法,样品用王水溶解,分离残渣,滤液定容后无需分离富集直接采用FAAS测定金量,方法精密度(RSD)为1.6%,优于FAAS本身精密度,满足了高品位金矿石样品快速分析监控的要求。通过实验对黑龙江省某岩金矿矿样(生产监控样)、金矿石外检样品及金矿石国家标准样品采用本法、泡沫富集-FAAS法、氰醌容量法、火试金重量法进行综合分析,结果表明样品基体中铁含量的高低直接影响到本法测定高品位金量的准确性。当金量为50~110μg/g时,允许样品中铁含量为10%;金量为110~164μg/g时,允许样品中铁含量为20%;金量为164~218μg/g时,允许样品中铁含量为25%。研究认为,本法普遍适用于测定金品位达到50μg/g以上、铁含量小于10%的金矿石。铁在地壳中的平均含量为5.63%,大部分金矿石国家标准样品的铁含量均在此平均值附近,一般金矿石的铁含量也很少达到较高水平,因此本法具备较强的应用性;且与泡沫富集-FAAS法相比,省去了泡沫富集-灰化-复溶的操作过程,大大提高了金量的分析效率。     

Study of 3D Geological Modeling Based on Aeromagnetic Data

With the increasing difficulty of finding the shallow surface deposit and the increasing depth of resources exploration, three-dimensional modeling technology is more apparent in deep prospecting, and its accuracy directly determines the cognitive degree of geological body and metallogenic condition. For this, we put forward a set of the extraction technology of abnormal information combined with aeromagnetic data processing with three-dimensional geological modeling. Inversing the selected profile of the study area and obtaining each profile geological model, we built three-dimensional geological model of geological units by the method of profile linked, using undulating terrain three-dimensional block magnetic field forward techniques to model the three-dimensional geological model of the whole area, and obtained the forward modeling results of the whole three-dimensional geological model and the geological unit. After the comparative analysis with the test result, adding reasonable geological constraints and revising model, through adjusting for many times, we made the model maximum close to the actual situation. The model can well reflect the geological information and make minimum fitting error of observations and theoretical field, with which geologists can use the most of their experience and get more regional geological understanding. Using the thought of main block and secondary block to subdivision modeling of geological body, on the condition of ensuring the accuracy of model, the number of the total model block decreased and the multi-window and multi-geological body parallel computing method were used to improve the modeling speed, effectively solve the limitation problem of the model complexity in the process of the three-dimensional inversion modeling method, and easily form complex and different sizes three-dimensional geological model. We applied this method to the Hubei Daye area, constructed the three-dimensional geological model of Daye Iron Mine, and verified the feasibility and rationality of this method.