A preliminary discussion on the bio-metallogenesis of Tl deposits in the low-temperature minerogenetic province of southwestern China

Starting with the research status of bio-metallogenesis of Tl deposits and their geology, this work deals with the geological background of Tl enrichment and mineralization and the mechanism of bio- metal-logenesis of Tl deposits, as exemplified by Tl deposits in the low-temperature minerogenetic province. This research on the bio-metallogenesis of Tl deposits is focused on the correlations between bio-enrichment and Tl, the enrichment of Tl in micro-paleo-animals in rocks and ores, bio-fossil casts in Tl-rich ores, the involvement of bio-sulfur in minerogenesis and the enrichment of bio-genetic organic carbon in Tl ores. Thallium deposits have experienced two ore-forming stages: syngenetic bio- en-richment and epigenetic hydrothermal reworking (or transformation). Owing to the intense epigenetic hydrothermal reworking, almost no bio-residues remain in syngenetically bio-enriched Tl ores, thereby the Tl deposits display the characteristics of hydrothermally reoworked deposits.     

浅谈《防震减灾法》在河北省贯彻执行中的问题及对策

从贯彻实施防震减灾法律法规的实践入手,针对《防震减灾法》在河北省贯彻实施过程中存在的问题,进行分析探讨,提出了解决的对策,目的在于更进一步促进防震减灾工作的深入开展。     

Development characteristics of interlayer oxidation zone type of sandstone uranium deposits in the southwestern Turfan-Hami basin

The known uranium ore and anomaly occur-rences are distributed mainly in the southwestern part of the Turfan-Hami basin. The focus of current explo-ration is placed on the leachable interlayered oxidation zone type of sandstone uranium deposits. Uranium deposits in the sedimentary basin can be classified into three types in accordance with their host rock types, i.e. the sandstone-type uranium deposits, the coal rock-type uranium deposits and the mud-stone-type uranium deposits. The sandstone…     

The unique nature in ore composition,geological backgroudd and metallogenic mechanism of non-conventional superlarge ore deposits: A preliminary discussion

The new plants documented here, including a representative of the trimerophytesPsilophyton primitiuum sp. nov., a questionable rhyniophyte or trimerophyteHedeia sinica sp. nov., a prelycopodBragwanathia sp. and two species of zosterophyllophytes,Zosterophyllum australianum Lang and Cookson 1930 and2. sp. 1, from the Posongchong Formation of southeastern Yunnan, China, add to the known floral diversity of the Early Devonian of this region. Two sections of the Posongchong Formation, Changputang section of Wenshan district and Gegu section of Mengzi district also are introduced. After comparing the plants with those of the coeval flora of Australia and considering the data of recent paleocontinental reconstructions, the authors suggest that there is a northeastern Gondwana phytogeographic unit during the early Devonian comprising Australia, South China Block and perhaps Shan-Thai Block. The similarity of the floral component between Australia and South China is discussed. Because both Australia and South China also have dominant or endemic taxa, each might be recognized as a subunit, separately characterized byHedeia for Australia andEophyllophyton for South China. Project supported by the National Natural Science Foundation of China (Grant Nos. 49372075 and 49742004)     

我国地震地下流体观测台网调整与优化方案探讨

本文首先简要介绍了我国地震地下流体观测台网的现状,然后针对其存在的主要问题提出了调整与优化的建议: ① 调整布局,重点加强我国中西部地区(105°E以西)的监测; ② 扩大规模,观测井(泉)数要达到1000个左右; ③ 全面提高观测井质量,淘汰不符合规范要求的观测井(泉),改造不完全符合规范要求的观测井,新建一批完全符合规范的观测井; ④ 优化观测项目的组合,大力发展观测井(泉)水流量观测,强化以H₂、 He、 CO₂等为主测项的断层带土壤气观测,建立断层带土壤气观测网; ⑤ 优化现有的观测模式,开展平面上的台阵式观测与垂向的多层次立体化观测; ⑥ 完善与提升现有数字化观测技术水平.      

我国火山灾害评估中的问题初探

文中讨论了我国火山灾害准确预报的可能性，对与火山灾害有关的一些重要问题，如高风险火山区的评估预测，火山灾害的预测评估的分期界定等进行了讨论。     

南岭东段钨锡多金属矿床地质特征、成矿模式及找矿方向

南岭东段地区是世界著名的钨多金属矿集区。近年来中国地质调查局在该区实施钨多金属矿调查评价,找到了一批具有中大型远景的与花岗岩有关的新类型钨锡多金属矿床,特别是在复式岩体中的花岗岩型新类型钨钼多金属矿床（简称＂体中体＂式钨钼多金属矿床）和受中、上泥盆统地层控制的层控矽卡岩型钨锡多金属矿床的发现,不仅实现了南岭东段地区找矿新突破,而且对整个南岭乃至我国华南地区钨锡多金属矿找矿具有重要指导作用。本文根据近年来南岭东段地区钨锡多金属矿找矿新成果,通过该区钨锡多金属矿床地质特征的总结,建立了南岭东段地区钨锡多金属矿成矿模式,提出了南岭东段地区今后钨锡多金属矿找矿方向应重点注意与燕山期复式花岗岩有关的＂体中体＂式钨钼多金属矿床和中、上泥盆统控制的层控矽卡岩型钨锡多金属矿床的寻找。     

西南地区次级构造块体与分区强震预报

依据西南地区现今构造、活动断裂和历史地震活动特点以及西南地区断裂带间相互作用等，将西南地区划分为次级构造区或次级块体——即将西南地区划分为5个构造次级块体，川青甘块体、川西块体、滇中块体、滇西南块体、川东南块体；针对西南次级构造区或次级块体的现今强震活动特征和历史中强地震特点，将中强地震归属划分为5个地震预测跟踪区，探讨基于西南次级构造区或次级块体的分区强震预报。     

钻孔岩心重定向的古地磁学新方法及其在华南铀矿床岩心定向中的初步应用

基于岩石剩余磁化强度的矢量特性,使用古地磁学方法对钻孔岩心进行重新定向,对于解译地下构造、分析应力特征、判定成矿方向等问题具有重要意义.针对华南地区复杂构造下的倾斜钻孔岩心,本文构建了古地磁学岩心定向新方法理论,结合多次坐标转换和磁场一致性扫描,实现了基于黏滞剩磁的岩心重定向;设计了定向所需的成套古地磁学岩心定向、测量、取样装置,并将该方法和装置应用于华南铀矿钻孔的重定向,恢复后的岩心特征剩磁计算获得的早白垩世古地磁极位置与同期华南地块的极位置一致.该方法对地球物理深部探矿技术的改进有一定意义.此外,所设计的研究装置在古地磁学研究对象的拓展中也具有应用前景.

     

A preliminary model for 3-D rheological structure of the lithosphere in North China

3-D rheological structure is mainly the spatial distribution of lithospheric strength or viscos-ity, its strength and viscosity are indispensable parameters in quantitative study of the lithosphere deformation. Plate tectonics theory initially divided the…     

青藏高原东北缘热水-日月山断裂带热水段古地震初步研究

通过遥感影像解译和详细的野外填图,获得了热水-日月山断裂带热水断裂段的断错地貌,其水系右旋断错量为140～940m.沿断裂带的探槽开挖,揭示距今9645±220 a B.P,热水段曾发生一次古地震事件;结合前人的研究结果,认为热水-日月山断裂带热水断裂段上古地震复发间隔约3365 a,全新世以来的倾滑速率为0.03 mm/a.热水-日月山断裂带上已揭露出3次古地震事件,分别为9865±40 a B.P～9425±35 aB.P,6280±120 a B.P和2220±360 a B.P,复发间隔为3500 a左右,由于该断裂段最近一次古地震事件距今已接近2220年,与其复发间隔3365 a年相比尚有一段时间,但考虑到古地震事件的不确定性和年代样品的误差,初步推断热水-日月山断裂带热水段的地震危险性不大,但不排除有中强地震的可能性.     

Large clusters of gold deposits and large-scale metallogenesis in the Jiaodong Peninsula, Eastern China

The Jiaodong Peninsula is the largest repository of gold in China based on the production in history. It covers less than 0.2% of China’s territory, but production of gold accounts for about one fourth of the whole country. Thus, the Jiaodong Peninsula is a typical area or case of large-scale metallogenesis and a large clusters of mineral deposits in China. It is characterized by the large clusters of gold deposits in large scale, high reserve and short mineralizing stage. In this study, we suggest that the eastern boundary of the large clusters of gold deposits is as same as that of North China Block, the gold deposits are hosted by Archean metamorphic rocks or Mesozoic granites, and the age of gold mineralization is 121.6 to 122.7 Ma. Gold and related ore-forming materials are derived from multisources, i.e. Archean metamorphic rocks, granites and intermediate-mafic dikes, especially, intermediate-mafic dikes and calc-alkaline granites. The metallogenic geodynamic process is constrained by the tectonic evolution of eastern North China Block during Late Mesozoic, and it is the result of the interaction between mantle and crust as the boundary plates are playing role on the block.     

一种基于地表能量平衡的遥感干旱监测新方法及其在甘肃河东地区干旱监测中的应用初探

目前遥感干旱监测方法的精度普遍不高,探求新的遥感干旱监测方法有助于干旱监测预警技术的提升与发展.波文比是感热通量与潜热通量之比,能综合反映地表水热特征,可尝试将其引入到遥感干旱监测领域加以利用.应用甘肃河东地区的EOS-MODIS卫星资料和同步地面气象资料,基于地表能量平衡原理构建了波文比干旱监测模型,对比分析了波文比（β）指数、温度植被指数（TVX）与土壤水分的相关性,并以典型晴空影像（2014年10月5日）为例初步建立了β的干旱分级标准,对研究区进行了旱情评估.结果表明：β与土壤相对湿度呈现出高度负相关,相比于当下广泛应用的TVX,β与0～20 cm平均土壤相对湿度具有更好的相关性,监测精度得到了显著提高.用β干旱分级标准评估的研究区干湿状况与前期降水空间分布吻合得相当好,评估表明2014年10月5日研究区基本为适宜（无旱）,与2014年9月的降水距平百分率特征一致.基于地表能量平衡的波文比（β）指数在干旱监测中效果突出,具有很好的应用前景.     

江西省会昌县淘锡坝大型锡矿床构造控矿机制探讨

淘锡坝锡矿床是近年探明储量达大型的锡矿床,是一种新的锡矿类型-隐爆层间裂隙带型。文章介绍了该矿床的地质特征和矿化特征,对矿区的构造进行了重点解剖,对构造控矿机理进行了探讨,提出火山机构及北东向断裂是矿区的控岩构造,控制了白垩纪成矿花岗岩体的侵入就位。而火山岩中大范围的隐爆层间裂隙带是良好的容矿构造,矿体赋存其中呈似层状,局部膨大形成厚达数十米的＂锡矿包＂。通过研究构造与矿化富集的内在联系,总结了该矿床的成矿规律。     

西藏及西南三江深断裂构造格局新认识

西藏和西南三江地区是青藏地区断裂构造最为复杂区域,历经数十年研究,对该区断裂构造的认识仍存在分歧.笔者以最新实测航磁数据并结合重力资料为基础,从重、磁场特征与地质构造研究相结合角度出发,新编制了西藏及西南三江地区的断裂构造格架图.研究结果表明,在西南三江流域的金沙江深断裂、澜沧江深断裂和怒江深断裂自南向北西延伸,没有与西藏地区的近东西向断裂呈弧形连接,而是一组独立存在的北西向断裂,这是在特提斯断裂系统中新发现的一组北西向断裂,它与发育在西藏地区的近东西向断裂分属于不同的断裂系,与前人提出的金沙江缝合带、龙木错—澜沧江缝合带和班公湖—怒江缝合带的走向呈北西—近东西向弧形分布特征的看法存在差异.这组断裂的发现改变了对西藏—西南三江地区断裂构造格架的认识,这为今后大地构造研究提出新的启示.文章重点展现西南三江(金沙江、澜沧江、怒江)深断裂带在重、磁场上的西延状况,并探讨了西南三江深断裂与西藏地区近东西向深断裂呈相交关系特征,同时也表明重、磁资料用于断裂构造的研究具有重要意义.     

我国地震海啸危险性初步探讨

概述了地震海啸的特征及其成因、国内外历史上发生地震海啸的情况,结合我国沿海的地震、构造、海底地貌等特点,分析了我国沿海发生地震海啸的可能性。最后简要叙述了卫星技术在地震海啸监测中的应用。     

Textual research of 1219 A.D. Guyuan earthquake in Ningxia Hui Autonomous Region,China and discussion on its causative structure

On the basis of textual research on the historical earthquake data and the field investigation of 1219 A.D.Guyuan earthquake,we suggest that there is only one strong earthquake occurred in Guyuan area in 1219 A.D.,instead of two or three strong earthquakes.We further suggest that the earthquake parameters recorded in the present earth-quake catalogs are not definite and should be modified.The occurrence time of this earthquake should be about 11 am,August 7,1219 A.D.and the heavily-damaged area of this earthquake,the VIII intensity area,should be lo-cated among the regions of Guyuan,Pingliang and Longde county cities.The epicenter area should be near Gu-yuan city.The magnitude of this earthquake is about 7 and it has intensity about larger than or equal to IX within the epicenter area.The major axis direction of the heavily-damaged area strikes in north-northwest that is ap-proximately consistent with the strike of the Liupan Shan thrust fault zone.The new tectonic activity of the Liupan Shan thrust fault zone resulted in the M7 Guyuan earthquake in 1219 A.D.     

海底地震仪远震记录接收函数反演: 以南海西南次海盆为例

伍德拉克裂谷位于巴布亚新几内亚东南部,是发育在澳大利亚板块和西南太平洋板块碰撞带中的年轻大陆裂谷,为研究汇聚构造背景下裂谷起始演化的地壳结构提供了理想场所。伍德拉克裂谷海域地区海水层的存在使得获取高质量地震数据成为难题,而数据主要通过海底地震仪（ocean bottom seismograph,缩写为OBS）获取。OBS的布放一般是自由下落式,其地震计的北向水平分量方位与地理北向通常不一致,这使得利用三分量波形数据获取的反演结果产生了较大误差甚至失效,例如接收函数方法。为确定伍德拉克裂谷地区OBS水平分量的方位偏转角度,本文同时引入纵波和瑞雷面波偏振分析方法进行方位校正,并利用校正后的三分量波形数据开展接收函数研究,进而约束该裂谷海域地区的地壳结构。结果分析表明,OBS方位校正后,其获得的可用接收函数波形数量显著增多,并且利用纵波偏振分析校正后的数据处理获得了更加合理的地壳结构。基于在该裂谷地区获得的地壳构造结果,基里比斯盆地和裂谷扩张轴所在的古迪纳夫盆地呈现对比鲜明的地壳结构特征：古迪纳夫盆地的地壳厚度朝着裂谷扩张轴处减薄,其平均值为（33.3±2.42） km;基里比斯盆地的地壳厚度更薄,平均值为（24.1±5.44） km。此外,研究区域内所有OBS处均观测到了较高的地壳纵横波速比值,这可能是巴布亚超镁铁质岩体富集和古俯冲残片脱水熔融共同作用的结果。     

断层的大地震复发概率研究

本文以布朗过程时间物理模型为基础, 以地震孕育过程为研究主线, 计算了中国大陆地区主要活动断层在不同预测时段内的强震复发概率, 进而对断层的地震危险性进行了研究。 结果表明: 鲜水河断裂带、 阿尔金断裂带、 东昆仑断裂带、 小江断裂带这4条断层的强震复发概率值显著高于其他断裂带, 反映了这些断层所处地区的应力积累水平高于其他地区, 应属于未来可能复发强震的危险地带。