The FAST/SKA site selection in Guizhou province

Many karst depressions with diameters of 300 m to 500 m, suitable for constructing Arecibo-style radio telescopes, were identified in the south of Guizhou Province by Remote Sensing (RS) and Geographic Information System (GIS) technologies together with field investigations. Fundamental topography and landform databases were established for 391candidate depressions, and using GIS the3-dimensional images of depressions, at a scale of 1:10000, were then simulated to fit a spherical antenna. This revised version was published online in July 2006 with corrections to the Cover Date.     

长江流域沿江镉异常源追踪与定量评估的方法技术研究:以长江流域安徽段为例

长江全流域性的Cd异常是被中国正在进行的多目标地球化学调查发现的重大生态环境问题。以长江流域安徽段为研究对象,对沿江镉异常源追踪与定量评估的方法技术进行了系统研究。通过对安徽段长江干流及其主要支流悬浮物中元素含量的测量查明:悬浮物是流域内重金属元素大跨度迁移的主要载体;Cd在悬浮物中的富集程度远远大于其他重金属元素,这或许正是Cd可以形成沿江流域性异常的主要原因;长江干流悬浮物中重金属元素含量的变化明显受到沿江支流的影响。安徽段长江干流及其主要支流重金属元素输出通量定量计算结果表明:秋蒲河是安徽段重金属元素输出通量最大的支流,每年在安徽段长江两岸土壤中沉积下约4.45t的Cd。利用悬浮物加密测量、1∶5万土壤测量和岩石测量对顺安河流域Cd异常源追踪结果显示:内生金属矿床特别是铅锌矿是悬浮物中Cd的最大的供应源。采用河漫滩沉积物分层采样技术和同位素测年技术,初步恢复了研究区Cd等重金属元素沉积和污染的地球化学历史,对研究区Cd等重金属元素异常的未来演变趋势进行了预警预测。     

Pelagic records from the Equatorial Ninetyeast Ridge and significant environmental events during the past 3.5 Ma

This paper presents pelagic records of planktic foraminifera, as well as data of stable isotope stratigraphy and carbonate stratigraphy since 3.5 Ma B.P. from site ODP758 in the Ninetyeast Ridge of the Indian Ocean. Based on these data, manifestations and related mechanisms of major tectonic and environmental events such as the rapid uplift of the Himalaya Mountains, “middle Pleistocene climatic transition” and “mid-Brunhes dissolution event” in the region are discussed. According to the analysis and comparison of various indices and changes in terms of foraminifera assemblage, paleotemperature, paleosalinity and themocline from site ODP758, the authors deduce that the paleoclimatic changes might correlate with the mid-Pleistocene transition at 1.4–1.7 Ma B.P. The changes of CaCO₃, mass accumulation rates (MAR) of CaCO₃ and non- CaCO₃ MAR indicate that the loaded terrigenous sediments increased at 1.7 Ma, which is in agreement with the uplift history of the Qinghai-Tibet plateau as shown by the available data. The last two changes coincide with the uplift of the Qinghai-Tibet plateau, hence they are called “Qinghai-Tibet movement” (1.7 Ma), and the “Kunlun-Yellow River movement” (1.2–0.6 Ma). The changes of the CaCO₃ content, coarse fraction (> 150 μm) content and planktonic foraminifera biostratigraphy show that strong dissolution of abyssal CaCO₃ occurred in the study region during 0.5–0.4 Ma. The event was consistent with the “mid-Brunhes dissolution event” in the sedimentary records of the Atlantic Ocean, Pacific Ocean, Indian Ocean and Nansha sea area of the South China Sea. __________ Translated from Geological Bulletin of China, 2007, 26(12): 1627–1632 [译自: 地质通报]     

Universal birefringent filter with a new double passband mode

This article describes the universal birefringent filter (UBF) which will be mounted at Taiwan. The UBF permits observations of solar images, vector magnetic fields and/or line-of-sight velocity fields in any Fraunhofer line in the wavelength region from 4000 to 7000 with half width from 0.05 to 0.14 . We have tested it at ten Fraunhofer lines under a spectral telescope in Huairou Station of Beijing Astronomical Observatory and obtained the passband profiles. The principles of magnetic field and velocity field measurement with the UBF are also described.     

蒙甘新相邻(北山)地区金铜矿床时空分布特征及成矿作用

文章首次对蒙甘新相邻(北山)地区各类金、铜和铜—镍矿床(点)地质特征、成因类型和空间分布特点进行了系统总结，论证了金、铜和铜—镍成矿作用与古生代岩浆活动的关系，对区域地壳演化过程中金、铜和铜—镍成矿的动力学机制进行了深入讨论。研究结果表明，该区的金矿床(点)大体可划分为变质岩型、火山岩型、斑岩型和深成侵入岩型；铜矿床(点)有斑岩型、夕卡岩型和铜—镍硫化物型。金和铜矿床(点)大都沿古板块汇聚带分布，与海西期火成岩具密切的时空分布关系，它们是古板块对接碰撞期和碰撞期后大规模构造—岩浆活动的产物。     

Exploration and Study on Deep Crust Structural Characteristics in the Jiashi-Artux Seismic Region

The data from two deep seismic sounding profiles was processed and studied comprehensively. The results show that crnst-mantle structures in the investigated region obviously display layered characteristics and velocity structures and tectonic features have larger distinction in different geological structure blocks. The boundary interface C between the upper and lower crust and Moho fluctuate greatly. The shallowest depths of C (30.0km) and Moho (45.5km) under Jiashi deepen sharply from Jiashi to the western Kunlun mountain areas, where the depths of C and Moho are 44.0km and 70.0km, respectively. The higher velocity structures in the Tarim massif determine its relatively “stable“ characteristics in crust tectonics. The phenomenon in the Jiashi region, where the distribution of earthquake foci mostly range from 20kin to 40kin in depth, may infer that the local uplift of C and Moho interface, anomalonsly lower velocity bodies and deep large faults control earthquake occurrence and seismogenic processes in the Jiashi strong earthquake swarm.     

江西利山金矿床地质特征及控矿构造

本文较系统地阐述了利山金矿床的各项地质特征，并重点就控矿构造问题进行了总结讨论，认为ＮＷＷ向断裂带严格控制了所有金矿体的产出。ＮＮＥ、ＮＮＷ向断裂与ＮＷＷ向断裂带的交汇部位控制了富矿段的产出。在此基础上初步探讨了矿床成因及找矿方向，这对该地区的找矿评价和开发均具有实际意义     

双频电磁波电导率层析成象

本文论述双频透射电磁波电导率层析成象方法。设｜Ｅ１｜，｜Ｅ２｜为在远场区观测的同一电偶极天线的两个辐射电场强度。如地质介质的电导率连续变化，观测场强的辐射频率ω１，ω２之差较小，则有如下的电导率层析成象方程｜Ｅ１｜－｜Ｅ２｜＝２０ｌｏｇ（ω１／ω２）＋２０ｌｏｇ（ｅ）μ／２（ω２－ω１）∫σ～（ｒ）ｄｒ式中σ＾＝σ，σ为介质的电导率。双频透射电磁波电导率层析成象方法克服了长期困扰电磁波吸收层析成象的初始辐射场强计算问题，应用实例表明它可获得更精确的层析图。     

福建晋江市前港湖、龙湖、虺湖等的地震堵塞成因研究

在国外前苏联学者尼可拉也夫曾提及地震后有的河流形成地震坝,其后再超覆沉积细粒物质,并称为"地震沉积相",显然这是指的地震堵塞湖形成后的沉积.国内最著名的地震堰塞湖是1933年四川省茂汶北的迭溪7.5级地震,这次强震不仅使迭溪全城及周围60余城镇、村寨全部毁灭,并且四山普遍崩溃,迭溪台地大规模崩塌、堵塞岷江,形成四个地震堵塞湖.大震后45天湖水溃决,造成下游水灾.类似这种地震堵塞湖是地震导致山地,丘陵或台地崩塌堵塞溪流,是地震导致的重力作用堵塞,应为地震重力堰塞湖.本文论及的地震堰塞湖即前港湖、龙湖、虺湖、丙州西侧小湖位于福建省晋江市龙湖镇西南侧,处晋江半岛中部,4个湖沿着控制深沪湾地堑北西边缘的衙口-丙洲断裂呈NE60°线状展布.该断裂与其东侧的深沪-金井断裂共同构成了全新世深沪湾地堑,卫星照片中有清晰的显示.这两条断裂及其所夹的活动地堑同属于区域性的常乐-诏安断裂带中段部份.     

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。