冀西石湖金矿中石英脉的热释光特征与其含金性研究

介绍了石英热释光测量方法在石湖石英脉型金矿找矿试验中的应用,结合峰型(单峰、双峰)、峰点温度和发光强度,本区石英脉的热释光曲线可分为4种类型,其中两峰发光强度相当,且强度值较小的双峰型曲线对应含金性较好的石英。石英热释光的发光强度、峰点温度和金品位等值线图表明,发光强度较低的石英脉含金性较好,峰点温度的低值—中值区为有利矿段,石英脉含金性较好。     

铝市震荡延续

铝价近月维持震荡走势。电价上涨带来成本上升的预期已被消化,铝价短期跟随金属板块重心下移趋势不改,价格上升的主要因素取决于电价再度上调以及供应趋紧的预期。如果现货价格走弱,利润消失,铝生产厂商不得不控制产能。     

冀西石湖金矿床中黄铁矿的热爆特征及其启示

研究了不同世代黄铁矿的爆裂温度、爆裂曲线等成因矿物学信息及其与金矿化的关系。结果表明,黄铁矿的起爆温度可划分为4个区间,依次对应Ⅰ→Ⅱ→Ⅲ→Ⅳ4个成矿阶段;黄铁矿热爆裂曲线归纳为A、B、C3种基本类型,含金性好的黄铁矿的热爆曲线大多是B型曲线,含金性差或不合金的黄铁矿的热爆曲线大多属于A型曲线;曲线上有中低温峰的黄铁矿金品位高,起爆至368℃的区间无峰的矿化好;初步认为该区在180m中段以下的19～31线和3—11线会出现金品位的高值区。     

Significance of zircon trace element geochemistry,the Shihu gold deposit,western Hebei Province,North China

The Shihu gold deposit is characterized by gold-bearing quartz-polymetallic sulfides and quartz veins.Both Mapeng granitoids batholith and intermediate-basic dikes intruded the metamorphic basement rocks,and are spatially associated with gold mineralization.Trace element abundances in zircons from the Shihu gold deposit,determined by laser-ablation microprobe ICPMS analysis,are sensitive to source rock type and crystallization environment.Concentrations of 21 trace elements were determined for zircons from granitoid rocks,diorites,quartz diorite porphyrites and gold-bearing quartz veins revealed some elemental characteristics and chondrite-normalized trace element patterns from different samples.There were no distinctive differences in REE concentrations of zircons from plutonic rocks and quartz veins,indicating that they probably had the same origin.Relatively flat chondrite-normalized REE patterns with(Yb/Sm)N ratios less than 60 characterized zircons from quartz diorite porphyrites and quartz veins.The highest Nb/Ta ratios were found in zircons from quartz diorite porphyrites,whereas the lowest ratios were found in quartz vein zircons.The Nb/Ta ratios were broadly correlated with HREE+Y contents,and had weak positive correlations with the depth of the Eu negative anomalies.High values U up to 0.4% and Th up to 0.1%,as well as positive correlations with REE+Y characterized zircons from quartz vein.The lowest Th/U ratios of zircons present in quartz veins reflected the relatively high concentration of U in hydrothermal fluid,and high Pb concentrations only typified quartz vein grains relatively enriched in U and Th.Zircons from quartz diorite porphyrites showed the most pronounced Ce anomalies,whereas weak Ce anomalies were typical of zircons from quartz veins,in which Eu/Eu* of zircons had a broadly negative correlation with Ce/Ce*.Trace element geochemistry of zircons from mineralized quartz veins and plutonic rocks confirmed that the sources of ore-forming materials were from Precambrian host rocks.Our results significantly enhanced the usefulness of zircon in crustal studies of the North China craton and as an indicator mineral in mineral exploration of the Taihang region.