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高频燃烧-红外碳硫吸收仪快速测定含铜烧结物料中的高含量硫 总被引：3，自引：3，他引：0
应用高频燃烧-红外碳硫吸收法测定含铜烧结物中的高含量硫。对样品称样量、助熔剂的种类、加入顺序、用量等测定条件进行研究。由于样品含硫量的不同,根据矿石标准样品中含硫量的比例关系确定具体的称样量。以纯铁屑和钨粒作助熔剂,高温燃烧分解试样,红外检测可定量测定含铜烧结物样品中含量为1%~23%的硫。方法加标回收率为94%~113%,相对标准偏差(RSD,n=6)小于2%。与经典的硫酸钡重量法对比,相对误差小于4%。建立的方法解决了大宗含铜烧结物中硫快速、准确测定的问题,已应用于实际的日常检验工作。 相似文献
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W. A. Robertson 《Australian Journal of Earth Sciences》2013,60(1):87-89
Umbrella‐shaped objects, presumably fossils, were collected from the Lower Proterozoic Noltenius Formation at two localities about 80 miles south of Darwin. Radial and concentric forms are described morphologically, and their probable mode of origin is discussed. 相似文献
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水热蚀变与泉华作为地热流体水-岩反应和化学沉积的产物,其相关研究可为水热活动发展史、恢复地热流体古温度及水岩反应过程等方面研究提供重要信息。古堆地热田位于错那—沃卡裂谷中部,是继羊八井地热田之后我国大陆最具发电潜力的非火山岩型高温地热田之一,极具开发潜力。为了解古堆地热田泉华和水热蚀变的类型、分布特征及判断有利的勘探方向,本文在野外地热地质调查的基础上,结合室内镜下鉴定和扫描电镜分析等工作,识别出绿泥石化、硅化、高岭石化和碳酸盐化等水热蚀变类型。研究发现,古堆地热田水热蚀变呈现出从蚀变中心向外由酸性蚀变过渡为弱酸性-中性蚀变的分带模式,蚀变中心常由强烈蚀变的硅化带或高岭石带组成;水热蚀变分布受断裂构造的控制,蚀变在断裂交汇处最为强烈,蚀变中心常沿着断裂延伸;根据水热蚀变的分布及蚀变强度,初步判断布雄朗古和杀嘎朗嘎的渗透性相对较好且热储温度高,具有较好的开发前景。在泉华沉积方面,古堆地热田西区主要为钙华区,东区为钙华和硅华叠加区;结合青藏高原动力学背景,认为古堆地热田水热发展史与陆陆碰撞的隆升过程及错那—沃卡裂谷活动密切相关且存在明显的耦合关系。 相似文献
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Speleothems and other carbonate deposits such as tufa containing high proportions of detrital material can be difficult to chemically date due to detrital thorium levels causing a high level of error in conventional U-Th disequilibrium dating. Here we investigate the use of an alternative technique centring on radiocarbon dating of organic matter preserved within the detrital fraction. Non-acid soluble humic, particulate and detritally absorbed organic matter was recovered from eight samples from a flowstone sinter formed within a roman aqueduct at Trento in Italy with a maximum age of 100 CE (1850 cal yr BP), and two repeat samples from a dripstone formed within the 20th Century on a wire fence at Lilly-Pilly Cave, Buchan Caves Reserve in Victoria, Australia. In the aqueduct samples the median calibrated 14C ages ranged from 2232 to 2889 cal yr BP, with 95.4% probability age range in the youngest and oldest samples of 2153–2337 and 2342–3449 cal yr BP respectively. The median age of the more modern dripstone was 336 cal yr BP, with a 95.4% probability age range of 148–486 cal yr BP. These results provide very approximate ball-park estimates of the age of the sample, but are consistently too old when compared to the known maximum ages of formation. It is hypothesised that this offset is due to a combination of the nature of the organic carbon transported from the source organic matter pools, and reworking of both modern and old organic carbon by in situ microbial communities. 相似文献
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A. Martin-Izard A. Paniagua J. García-Iglesias M. Fuertes Ll. Boixet C. Maldonado A. Varela 《Journal of Geochemical Exploration》2000,71(2):217
This paper presents the petrographical, mineralogical and geochemical characteristics of the Carlés Cu–Mo–Au ore deposit, located in the Rio Narcea Gold Belt (Cantabrian zone of the Iberian Massif). It is related to a small postkinematic calc-alkaline monzogranite, which intrudes as a cedar-tree laccolith into the upper siliciclastic Furada Formation (late Silurian age) and the Nieva carbonates (early Devonian age). The Carlés deposit consists mainly of a well-developed exoskarn. The exoskarn is mostly calcic skarn made up of early garnet and pyroxene, and later amphibole, magnetite and sulfides. The presence of magnesian skarn has been recorded on the north side of the intrusion (roof of granitoid). Magnesian skarn consists of olivine, which is partially replaced by diopside and phlogopite and spinel. Close to the igneous rock, skarns are overprinted by strong potassic alteration. The ore is related to the skarn retrogradation and post-skarn veining and faulting. The skarn-related ore consists of earlier, uneconomic magnetite and Fe–As sulfide assemblages and economic Cu–Au–Ag (Bi–Te) assemblages on the eastern and western sides of the contact aureole, and uneconomic Mo and subeconomic Fe–As–Cu–Au–Ag on the northern side of the contact. Later subeconomic Fe–As–Sb–(Zn–Sn–Cu–Au–Ag) assemblages crosscut the granitoid, skarn, marbles and mineral associations developed previously, and are related to younger episodes of fracturing and faulting. Fluid inclusions in the first hydrothermal stage consist of an aqueous solution with significant contents of CO2, which reach unmixing conditions as a result of a decrease in P–T conditions. This led to two types of solutions, aqueous solutions of moderate to high salinity and hydrocarbon solutions of low salinity. This unmixing phenomenon controlled the first stage of gold precipitation. During the late hydrothermal activity, primary low-salinity-aqueous-carbonic inclusions with contrasting densities are found. They homogenize into vapor, critical or liquid phase. Homogenization temperatures are practically the same in all inclusions, indicating a boiling phenomenon that could control a new precipitation of gold. 相似文献
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大理岩型红宝石矿床成因研究 总被引：1，自引：0，他引：1
大理岩型红宝石矿床是红蓝宝石矿床的重要类型。对此类型矿床与找矿相关的成因问题，长期存在模糊认识。本文在实际研究和文献资料整理的基础上，得出以下结论：大理岩型红宝石矿床产于有深大断裂构造活动的深成造山变质带；含矿岩石是钙质结晶大理岩，而非鲜质大理岩或镁质夕卡岩；含矿岩石中的角闪石为富铝贫硅含铬的钙质闪石，如含铬的镁砂川闪石，而非绿色透闪石；矿床成因类型属区域热动力变质型，而不是“气成－热认型”或“夕卡岩型”。 相似文献
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Pb-Zn-Ag-bearing M anganoan Skarns of China 总被引：2，自引：0，他引：2
ZHAO Yiming LI Daxin Institute of Mineral Resources Chinese Academy of Geological Sciences Beijing 《《地质学报》英文版》2004,78(2):524-528
Manganoan skarns consist of special Mn (Ca, Mg, Fe, Al) silicate metasomatic minerals and are usually associated with Pb-Zn(Ag) mineralization. They occur chiefly along the lithologic contacts or faults and fractures of carbonate wall rocks distal from the intrusive contact zone, and are combined with Fe, Cu, W, Sn and Cu-bearing calcic or magnesian skarns occurring in the contact zones to constitute certain metasomatic zoning. Manganoan skarns are formed later than calcic or magnesian skarns. Their rock-forming temperatures are lower than those of calcic or magnesian skarns. The mineral assemblages of manganoan skarns occurring in different carbonate rocks (limestone or dolomite) are notably different. 相似文献
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Thomas T. Sorulen Ryohei Takahashi So Tanaka Kana Suzuki Akira Imai Yasushi Watanabe Shingo Kikuchi 《Resource Geology》2019,69(4):402-429
The Utanobori gold deposit is a low‐sulfidation, epithermal vein‐type deposit located in northern Hokkaido, Japan. The deposit is hosted by conglomerate, sandstone, and tuff of the Middle to Late Miocene Esashi Formation. These rocks were hydrothermally altered. Silica sinters and quartz‐adularia veins are common in the deposit. The quartz‐adularia veins either contain a ginguro band, which corresponds to the main gold‐bearing vein (Type 1 Veins), or do not contain a ginguro band but contain minor adularia (Type 2 Veins). Type 1 Veins are divided into three stages with 12–14 substages. Ore minerals identified include electrum, naumannite, chlorargyrite, bromargyrite, an unidentified Fe‐Sb mineral, and an Fe‐(Sb)‐As mineral. These ore minerals formed in the main mineralization stages I (bands I‐b and I‐d) and II (band II‐a). Scanning electron microscopy with cathodoluminescence images show that cathodoluminescence‐dark microcrystalline quartz exhibiting colloform (ghost‐sphere) texture is closely associated with ore minerals in the Type 1 Vein and Type 2 Vein, and the Al and K contents of such quartz are commonly >1000 ppm. This indicates that the ore minerals were crystallized from alkaline, silica‐saturated fluids at temperatures <200°C, which initially deposited amorphous silica that was recrystallized to microcrystalline quartz. The average Au content of electrum is 52.5 at% Au (n = 10), 65.7 at% Au (n = 20), and 55.5 at% Au (n = 5) in bands I‐b, I‐d, and II‐a, respectively, of Type 1 Veins. The δ34SCDT values of two fine‐grained disseminated pyrites in the altered conglomerate and bedded tuff in the argillic altered zone are ?4.3 and ?4.2‰. Ar‐Ar dating on adularia yielded 13.6 ± 0.06 Ma, 13.6 ± 0.07 Ma, and 13.6 ± 0.06 Ma for the stages I, II, and III of the Type 1 Vein, respectively. K‐Ar ages determined on adularia in the silica sinter and on whole‐rock of glassy rhyolite of the Esashi Formation are 15.0 ± 0.4 Ma and 14.6 ± 0.4 Ma, respectively. These radiometric ages indicate that silica sinter associated with the rhyolitic volcanic rocks formed prior to the main gold mineralization. 相似文献