Indium Enrichment in the Meng'entaolegai Ag-Pb-Zn Deposit, Inner Mongolia, China

Abstract. The Meng'entaolegai In-rich Ag-Pb-Zn deposit is located in the eastern part of Inner Mongolia. It is one of the In-richest deposits in China. Large amounts of quartz and sulfide minerals constitute a hydrothermal quartz-sulfide vein deposit within a Hercynian acidic granite massif, which occupies an area of about 400 km². Thirty-six orebodies, controlled strictly by the E-W trend faults, are found in the orefield of 6 km in length from east to west and 200 to 1,000 m in width from south to north. The ore minerals are mainly galena, sphalerite and pyrite, and subordinate chalcopyrite, arsenopyrite, cassiterite and stannite with many Ag-minerals. The gangue minerals are mainly quartz, calcite, sericite and chlorite. Economic components of the deposit are dominated by Pb andZn (reserves of Pb and Zn are 0.17 Mt and 0.37 Mt, and their grades are 1 % and 2.3 %, respectively), with Ag, Sn, In and Cd (1,800 t Ag, >2,000 t Sn, >500 t In and 1,800 t Cd) as by-products. Indium is highly enriched in ores and its contents are 9 to 295 ppm in ores and 85 to 2,660 ppm in sphalerite. Analytical results show that the ore-forming fluid of this deposit contains 0.8–3.5 ppm In and 4–36 ppm Sn, and the two elements show a very good positive correlation with a correlation coefficient of 0.8672, while the correlation between In and Zn in the ore-forming fluids, with a correlation coefficient of 0.5723, is not as good as that between In and Sn. This indicates that indium has an affinity with tin in the ore-forming fluids. The authors think that this is probably the main reason why those In-rich deposits spread over the world are simultaneously enriched in tin.     

MODIS数据在黄河凌汛监测中的应用

对MODIS数据的特性及其在黄河凌汛监测中的应用情况进行了探讨和总结。试验结果表明 ,MODIS数据在冰雪检测方面具有很大的潜力     

顺义地裂缝成因与顺义-良乡断裂北段第四纪活动性讨论

本文通过钻孔地层对比方法研究了顺义一良乡断裂北段的第四纪活动性，资料显示该断裂在第四纪期间呈现强弱交替的分期活动特征，距今315万年以来有3个较强活动期和3个较弱活动期，前三者分别距今266～315、171～228、73～147万年，后三者距今分别为228．266、147～171、0～73万年。中更新世晚期以来断裂活动不明显。超量开采地下水导致地面不均匀沉降是造成顺义地裂缝现今活动的主要原因。     

Upper-Tropospheric Environment–Tropical Cyclone Interactions over the Western North Pacific: A Statistical Study

Based on 25-year(1987–2011) tropical cyclone(TC) best track data, a statistical study was carried out to investigate the basic features of upper-tropospheric TC–environment interactions over the western North Pacific. Interaction was defined as the absolute value of eddy momentum flux convergence(EFC) exceeding 10 m s~(-1)d~(-1). Based on this definition, it was found that 18% of all six-hourly TC samples experienced interaction. Extreme interaction cases showed that EFC can reach~120 m s~(-1)d~(-1) during the extratropical-cyclone(EC) stage, an order of magnitude larger than reported in previous studies.Composite analysis showed that positive interactions are characterized by a double-jet flow pattern, rather than the traditional trough pattern, because it is the jets that bring in large EFC from the upper-level environment to the TC center. The role of the outflow jet is also enhanced by relatively low inertial stability, as compared to the inflow jet. Among several environmental factors, it was found that extremely large EFC is usually accompanied by high inertial stability, low SST and strong vertical wind shear(VWS). Thus, the positive effect of EFC is cancelled by their negative effects. Only those samples during the EC stage, whose intensities were less dependent on VWS and the underlying SST, could survive in extremely large EFC environments, or even re-intensify. For classical TCs(not in the EC stage), it was found that environments with a moderate EFC value generally below ~25 m s~(-1)d~(-1) are more favorable for a TC's intensification than those with extremely large EFC.     

多波束测量的精度控制与规范指标

分析多波束测量、辅助测量的数据精度,研究其对成果水深的影响程度,结合《海道测量规范》与《多波束水深测量技术规定》中的测量等级指标,以及IHO规范中对水深不确定度的定义和传播结构的介绍,建立数学模型反解出符合规范的作业环境与辅助测量数据的等级指标,提出明确的多波束测量作业精度控制的技术指标,为测量数据的质量监控建立更全面的评价标准。     

Late Quaternary Slip Rate of the Xiugou Segment,Eastern Kunlun Fault Zone

The Eastern Kunlun fault zone (EKLF) is a large left-lateral strike-slip fault, whose slip rate is meaningful to seismic hazard assessment and geodynamics of the Tibetan Plateau. Previous studies suggested that the late Quaternary average slip rate was stable and uniform (10~13 mm/a) in the central and western segment of the EKLF. But there were a few researches of accurate slip rate in the central segment on the EKLF. Therefore, we focused on an offset and well preserved alluvial fan from Xiugou basin, located in the east of Xidatan-Dongdatan, to make it clear. Moreover, we used high-resolution satellite images and digital elevation model extracted from SPOT7 stereo image pairs to restore the offset alluvial fan, and combined terrestrial cosmogenic nuclides method, including 13 quartz-rich samples from this fan surface, 1 quartz-rich sample from the main active channel bed and 1 ¹⁰Be depth profile from this fan edge to eliminate the ¹⁰Be concentration of inheritance accurately, with 1 optically stimulated luminescence sample to obtain the reliable age of this alluvial fan together. Referring to field observations, this alluvial fan was offset left-laterally by (1 862±103) m, and its age is (76.55±3.20)~(106.37±3.38) ka which can be determined through the actual geologic setting and improving chi-square test. Thus, we used the Monte Carlo method to obtain a left-lateral slip rate of (20.3+3.5/-2.3) mm/a with 68% confidence envelopes since the late Pleistocene in the Xiugou basin. As a result, combining with the results of previous studies, the left-lateral slip rate indicated that the obviously decreasing activity transferred from late Pleistocene to Holocene on the central segment of the EKLF.     

地质雷达电磁干扰分析及在隧洞岩溶探测中的应用

将地质雷达用于千岛湖配水工程某隧洞岩溶探测,分析了倾斜状电磁干扰异常与溶洞雷达异常差异,通过雷达剖面及疑似异常区单道时间-频率谱的分析,推断了隧底岩溶的性质及空间分布特征,含水溶洞在雷达剖面反映为同相轴错断,强振幅及能量高衰减的特性,高频干扰波振幅幅值较异常区小且能量不满足随时间推移逐渐衰减的规律,雷达成果为隧洞安全施工提供了准确的参考。      

青藏高原新生代古高度研究：现状与展望

青藏高原新生代古高度研究是地球系统科学研究中的一个热点、难点和重点,它是解决地球深部动力学、地貌地形演化和气候变化等各部分相互关系的一个关键突破口。目前以古生物和氧同位素为代表的各种古高度计被用来重建青藏高原新生代的古高度历史,但是不同的研究方法所得到的结果并不一致,关于青藏高原何时隆升到现在的海拔高度存在晚上新世、晚中新世和始新世等不同认识。因为古高度结果的差异,所以对于青藏高原新生代的构造隆升过程和动力机制也存在大的争议。本文首先详细的阐述了部分古高度计的应用原理及其各自的优缺点,收集总结了78条青藏高原古高度研究的成果,梳理了目前青藏高原新生代古高度研究的历史和现状。然后在此基础上讨论了目前高原古高度研究的特点和存在的问题,即地层年代学、氧同位素和古生物古高度计结果的协调、“以点带面”、区域研究程度差异较大、替代性指标的多解性、古纬度影响、地质时期温度递减率的不确定性、全球气候变化的影响等特点和问题。最后就存在的特点和问题指出在恢复青藏高原新生代古高度时所需要完善和注意的方面,其中最重要的是注重地层年代学的可靠性。     

桂西北丹池成矿带He、Ar同位素特征及其矿床成因指示

桂西北丹池成矿带是我国南方重要的有色金属矿业基地.本文对成矿带内芒场矿田马鞍山Pb-Zn矿和大山Sn-Zn矿、大厂矿田铜坑Sn多金属矿、五圩矿田箭猪坡Pb-Zn多金属矿等4个主要矿床矿石黄铁矿流体包裹体He、Ar同位素进行了研究.结果 表明,丹池成矿带内典型矿床成矿流体的3He/4He=0.79～5.32 Ra,介于地壳流体(0.01～0.05 Ra)与地幔流体(6～9 Ra)特征值之间,40Ar/36 Ar=273～351,接近或略高于大气40 Ar/36 Ar特征值(295.5),不同矿床成矿流体中均有幔源组分的参与,地幔流体参与成矿作用是一个区域性事件.结合区内泥盆纪喷流沉积作用、燕山晚期花岗质岩体及构造特征等综合研究认为,参与成矿作用的地幔组分主要来自壳幔相互作用过程中沿NW向深大断裂上升的深源地幔流体,丹池成矿带内成岩、成矿作用是燕山晚期同一构造-热事件产物,矿床成因属后生热液充填交代成矿.