安徽东至兆吉口铅锌多金属矿床地质特征及找矿方向

安徽东至兆吉口铅锌多金属矿床与长江中下游成矿带安庆-贵池矿集区南侧毗邻,区域成矿地质条件优越.通过对区域地质背景、矿区地质特征、矿区物化探成果和矿体地质特征进行分析研究,得出兆吉口铅锌矿主要产于兆吉口倒转背斜核部蓟县系环沙组下段细碎屑变质岩中的断裂或裂隙中,综合分析认为兆吉口矿床可能为浅变质岩断裂带中的中低温充填交代脉型铅锌矿床类型.激电测深、磁法和地球化学方法在该矿床具有良好的找矿效果,磁性特征显示兆吉口矿床下部存在隐伏岩体,化探特征显示异常区位于东至断裂与岩体接壤区.综合矿区地质特征和物化探特征,指出该区下一步找矿方向.     

S同位素示踪热液矿床成矿物质来源综述

具有明显分馏效应的硫同位素以各种含硫物种广泛赋存于热液成矿作用过程中,因此硫同位素成为示踪热液矿床成矿物质来源的主要方法之一。本文在总结前人研究基础上,综述了应用硫同位素在研究热液矿床成矿物质来源问题上的多解性,认为硫同位素示踪应用须在了解热液矿床地质前提下,准确区分成矿期次,判别硫同位素分馏平衡状态,结合Ohmoto模式才可以准确赋予同位素的地质意义。     

晴隆大厂锑矿流体包裹体研究

晴隆大厂锑矿是西南地区大型锑矿之一。前人已进行过深入的研究,在很多方面已达成共识,但对其成矿流体性质和来源尚有争议。本文通过对大厂锑矿流体包裹体的温度与盐度、密度与压力、包裹体成分和氢氧同位素等的研究,得出大厂锑矿成矿流体属于中低温（129．4～214c（=）、低盐度（NaCI）0．18％～3．23％、中等密度（0．93—1．03g／cm3）;流体水化学类型属F-=SO4^2- -K＋-Ca＋型。流体压力为超高压（103．97087836MPa）;成矿流体主要是大气降水形成的地下热水,可能有部分岩浆热液的掺入。     

Identification of the deposited layers in landslides reservoir and investigation of the sediment yields during the later sixteenth century on the Hill Loess Plateau,China

There are many sediment trapping reservoirs in the Hill Loess Plateau. The Huangtuwa small catchment is selected as a research field where samples were collected in a sediment deposit profile with a vertical length of 12.73 m. By the variation of fine particle content and pollen concentration, 54 flood couples were identified. Taking the freeze-thawing disturbed texture as the sign of the latest flood couple in a year, it is ascertained that those 54 floods should happen in 31 years. Using pyramid volume calculation formula, the sediment yields of flood ranged between 716-30376 t· km^-2, The average sediment yield was 7106 t· km^-2, The annual sediment yields varied between 968-55579 t· （km^2· a）^-1, and the average value is 12629 t· （km^2· a）^-1. Compared with the modern annual sediment discharge of the Huaining River, the erosion rate in the Huangtuwa region 450 years ago was similar to the modern erosion rate. In the period from the 27th year to the 31st year, the average annual sediment yield increased sharply to 31309 t· （km^2· a）^-1. It implied that re-reclamation of the abandoned land in the catchment since the landslide disaster, where vegetation had rehabilitated already, caused very severe soil erosion in the catchment.     

西南某高速公路库区段冰水堆积物塌岸预测及模式研究

某高速公路路线通过西南某水电站冰水堆积物岸坡,在水库蓄水及运行期间,路基外侧冰水堆积物岸坡将出现一定程度的塌岸与库岸再造.在现场调查分析的基础上对冰水堆积物岸坡的塌岸模式进行了系统的分析,研究分析表明,岸坡的失稳具有整体性,塌岸模式为淘蚀-坍塌.最后,针对工程地质条件和岸坡结构特征较特殊的冰水堆积物岸坡,采用适合坍塌类塌岸预测的两段法和适合整体失稳评价的极限平衡法对该段岸坡进行塌岸预测比较,计算分析表明,采用极限平衡法进行该岸坡的塌岸预测是相对较可靠的.     

贵州早二叠世茅口晚期成锰环境及锰矿远景预测

贵州二叠系茅口组中的锰矿有两种类型:一类是茅口组顶部的含锰硅质岩、含锰灰岩和菱锰矿层;另一类是茅口组顶部的含锰岩系经风化淋浊而形成的位于古岩溶侵蚀面之上的遵义式锰矿,含锰岩系为含植物化石、海相化石的粘土岩、含锰粘土岩和菱锰矿层。然而,形成这些锰矿的原生含锰岩系仅分布于台沟相带内,因此,据茅口晚期古地理特征,可分出两个含锰矿带:毕节——仁怀和宣威——遵义含锰矿带;毕节——仁怀和宣威——遵义含锰矿带,其中宣威——遵义含锰矿带可进一步划分出黔北——黔中遵义式锰矿区和黔西原生沉积锰矿区,并提出后者是贵州锰矿勘探的主要目标,特别是在该区寻找含锰岩系古风化面,是寻找具工业意义锰矿的关键。     

He-Ar isotopic system of fluid inclusions in pyrite from the molybdenum deposits in south margin of North China Block and its trace to metallogenetic and geodynamic background

The helium and argon isotopic compositions of the ore-forming fluids from the molybdenum deposits such as Jinduicheng, Donggou, Shijiawan, and Sandaozhuang, which are located in the East Qinling molybdenum belt in south margin of North China Block （SMCNB）, are reported in this paper. The origin and the evolution of the ore-forming fluids and their coupled-relationships with the intra-continental collision and orogenic process of Qinling Orogen in Mesozoic-Cenozoic have been discussed. The 3He/4He and 40Ar/36Ar values （3He/4He=1.38-3.64 Ra, and 40Ar/36Ar=295.68-346.39, respectively） of the fluid inclusions in pyrite from the molybdenum deposits in East Qinling suggest that, the ore-forming fluid system is mixed by two end members. One is the high temperature deep-derived fluid congenetic with the porphyries generated by crust-mantle mixing, and the other is the low-temperature meteoric water which is rich in crustal radiogenic He with the component of atmospheric Ar. From the Pb isotopic composition, and ore-bearing potential of the porphyry and the regional stratum, we can conclude that the ore-forming materials of the deposits in the East Qinling molybdenum belt are derived from the deep source by the mixing of lower crust and upper mantle. Therefore, the formation of the molybdenum deposits in SMNCB can be related to the crust-mantle interaction, which is accompanied by the intra-continental orogenic and extension process in the post-collision period of Qinling Orogen. The granitic porphyries which are related to Mo mineralization are not simple crust-remelting type granites or S type granites, but belong to syntexis-type or mantle-derived granites, hence their formation has a profound and regional geodynamic background.     

青藏高原通天河盆地五道梁组介形虫壳体Mg/Ca和Sr/Ca地球化学特征及古环境意义

中新世早期青藏高原腹地曾经发育了面积巨大的古大湖,此时恰逢青藏高原的快速隆升关键时期.为研究高原腹地在此期间环境的演化,对五道梁组中介形虫壳体的Mg/Ca 和Sr/Ca的值进行了测试.通天河盆地五道梁组地层中的介形虫壳体的Mg/Ca 和Sr/Ca数值的特征,结合剖面岩性特征,反映了23.8～21.8 Ma前该湖泊区域气候由湿润-干旱-暖湿的演化趋势.其气候的变化可能是此时期青藏高原从快速隆升到剥蚀夷平后高原北部构造隆升活动的结果.该研究为进一步了解青藏高原腹地的古环境探索了一条新的途径.     

地质植物法在黔西南滥木厂铊(汞)矿床的初步应用

依据黔西南滥木厂铊(汞)矿床地质特征,在对与矿化有关的植物组合及其分布特征进行研究的基础上,以大金发藓(Polytrichum Commune Hedw)为例对其进行了地质植物法填图.按120×60 m布置观察点,对其分布密度进行统计,编制密度等值线图,讨论了密度等值线展布方向和不同密度等值线分布区与北东向断裂带、蚀变带、矿化带以及矿化中心的关系,并指出了其找矿意义.根据大金发藓常与芒箕[Dicranopteris dichotoma(Thunb.) Bernb.]、南烛(Lyonia Sp.)、蜈蚣草(Pteris Vittata L.)等共生密切,结合其灰分分析资料计算成矿元素富集系数,分析了这一特征植物组合对找寻滥木厂式铊(汞)矿床的作用.     

质子探针研究微细粒金的赋存状态及黄铁矿标型特征——以皖南地区金矿成矿带为例

皖南东至 泾县一带是安徽省主要的金矿 (点 )之一 ,而黄铁矿是本区中金矿床(点 )最主要的载金矿物之一 .论文应用先进的微束分析技术———质子探针分析———对皖南东至 泾县一带金赋存状态进行系统的研究 ,得出初步结论 .结果表明 ,矿体黄铁矿中金的赋存状态以微细粒自然金为主 ,与我国卡林型金矿床中的金的赋存状态一致 ;通过对本区微细浸染金矿带中花山、吕山、柴山、虎龙冲、管岭、白果树等金矿床 (点 )中黄铁矿化学成分和晶体形态等方面标型特征的研究来探讨本区金矿床 (点 )的成矿条件 ,为指出找矿方向 ,筛选出找矿靶区作了一个有益的尝试