安徽省濉溪县后马场铜镍矿矿床地质特征及成矿机制浅析

后马场铜镍矿是淮北地区目前唯一基性岩铜镍矿,本文论述该矿矿床地质特征及成矿模式,指出围岩、岩浆岩、构造是主要控矿因素,属由岩浆熔离作用而形成的基性岩铜镍矿。对在本区基性岩中寻找铜镍金属矿具有很好的指导意义。     

内蒙古四子王旗小南山铜镍矿典型矿床特征

内蒙古四子王旗小南山铜镍矿大地构造位置属华北陆块区狼山——阴山陆块之狼山——白云鄂博裂谷及色尔腾山——太仆寺旗古岩浆弧。与铜形成有直接关系的侵入岩为中元古代辉长岩、橄榄岩等基性—超基性侵入岩。区内铜矿床多与该期杂岩体有时间、空间和成因方面的密切关系。     

新巴尔虎右旗哈拉胜格拉地区控矿地质条件及矿产远景调查

研究区位于北东向德尔布干——呼伦湖深大断裂带的北西侧,额尔古纳兴凯褶皱带西南段。区内大多数矿床在时空分布上均与燕山期和华力西期花岗岩类侵入体有关,显示了构造岩浆活动与成矿作用的密切关系。在矿床的成矿时代上,主要集中在燕山期。其优势矿床类型为斑岩型铜、钼矿床、热液脉型银、铅、锌矿床。     

内蒙古乌拉特后旗查干花铜钼矿床地质特征及找矿标志

查干花钼矿床位于苏尼特右旗晚华力西地槽褶皱带,宝音图台隆中段,是乌力吉——锡林浩特铜、铁、铬、金、萤石成矿带内发现的又一大型斑岩型铜钼矿床。查干花钼矿床主要赋存早二叠世花岗闪长岩体处、北西和北东向断裂构造交汇部位。矿区内围岩蚀变强烈,并具有明显的分带性。辉钼矿呈星散状分布于脉石中形成的浸染状构造。笔者在分析矿床的成矿地质背景、矿床地质特征的基础上,初步总结了成因及找矿标志。认为查干花铜钼矿床的发现是该区域找矿的重大突破,显示出良好的区域找矿前景。     

长江中下游成矿带燕山期矿床成矿系列研究进展

长江中下游成矿带是中国重要的铜铁金多金属成矿带之一,矿床类型繁多。其中,铜铁金成矿系列主要由矽卡岩型、斑岩型和热液脉型矿床构成,系长江中下游成矿带主要的成矿系列,与燕山期岩浆活动关系密切,且成岩成矿特点显著。本文在前人对近年来长江中下游成矿带燕山期矿床成矿系列的研究进展的基础上做出归纳总结。     

新疆哈密市黄山南镍矿床地质特征及成因

哈密黄山南镍矿床位于塔里木板块前沿活动带,觉罗塔格石炭纪岛弧带东部,干墩大断裂南侧土墩——黄山——镜儿泉基性——超基性杂岩带内,处于黄山——镜儿泉铜镍金钼成矿带中.镍矿床赋存于韧性剪切带内的超基性岩脉中,具有较强的矿化蚀变,主要有绢云母化、录泥石化、磁铁矿化、黄铁矿化、黄铜矿化等.通过对矿床地质特征研究,该镍矿床受黄山——镜儿泉深大断裂控制,随着华力西期构造运动的影响,位于深部的含矿超基性岩浆和矿浆上升侵位并于构造薄弱部位形成超基性岩浆熔离型矿床.     

内蒙古新巴尔虎左旗罕达盖铁铜矿矿床地质特征及找矿标志

罕达盖铁铜矿床是近几年内蒙古国土资源大调查工作中新发现的一个小型铁铜矿床。矿床产于石炭纪石英二长闪长岩与中奥陶统多宝山组地层外接触带的矽卡岩中,矿体的形态及空间分布受接触带控制,矿体的产状随着岩体与地层的接触带及矽卡岩总体产状的变化而改变,属典型的矽卡岩型铁铜多金属矿床。本文通过对区域地质、矿区地质、物化探异常特征及矿体的特征进行研究,总结了矿床地质特征及找矿标志,并对控矿因素和矿床成因进行了探讨,对今后矿区及其外围的找矿工作具有指导意义。     

河北丰宁草原萤石矿床地质特征及矿床成因

河北丰宁草原萤石矿床探明储量规模已达特大型,成矿地质条件良好,但是对该矿床的成因研究等方面的工作仍有欠缺,总结其矿床地质特征及成因对后续资源的进一步开发有着重要意义。本文在详尽野外调研工作的基础上,结合已有的探矿工程,对矿体的空间分布、赋存状态及控矿因素进行了分析,探讨该矿床成因,确定了丰宁草原萤石矿受控于北北西及北西向断裂构造,直接围岩为白垩系张家口组火山岩。矿体与区内出露的花岗斑岩空间关系密切,主要赋存于花岗斑岩附近断裂破碎带中,为岩浆期后热液贯入形成的热液充填型矿床,控矿构造延伸稳定,在深部仍有较大的找矿空间。     

内蒙古三河铅锌矿床同位素特征与矿床成因探讨

三河铅锌矿床主要产于北西西向的构造裂隙中,矿体多呈脉状、透镜状,严格受构造的控制,矿床成因类型为中低温岩浆热液型铅锌矿床。该矿床处于得尔布干成矿带的北段,构造发育,岩浆活动频繁。铅同位素数据指示成矿金属来自地幔和地壳,硫同位素δ34SCDT在+1.6‰~+6.2‰之间,具有幔源岩浆热液来源的特征。成矿热液的主体是以岩浆水和大气降水的混合水为主。     

新疆青河县夏干伊尔盖中—基性杂岩体特征及找矿前景

新疆青河县查干郭勒地区中—基性杂岩体矿物成分复杂,由多期岩浆侵入形成,存在有深断裂,圈出许多强负磁异常,实施的钻孔中发现钒钛磁铁矿化体,具有寻找与基性—超基性岩有关的隐伏铜镍矿床的良好找矿前景。     

Women,Politics, Elections,and Citizenship

Abstract

Significantly more women than men are registered voters in the United States, and a higher proportion of women voters actually cast ballots on election day. Yet the 106th Congress (1999-2001) includes only 56 women members, 12% of the total membership of the House and Senate. Likewise, women hold only 22% of the total seats in state legislatures. The purpose of this article is to examine this paradox. It first examines the history of the women's movement in the United States. It then turns to an evaluation of women's progress in gaining elected office. Finally it considers three primary obstacles to women gaining equitable representation: solidarity among women, political culture, and the single-member district system now employed in the United States.     

Elevation, Age, Soil Development, and Chemical Weathering at Storbreen, Jotunheimen, Norway

Chemical weathering and associated soil development trends on glacial forelands are commonly assumed to exhibit increases with time elapsed since glaciation. However, this gross trend is complicated by several other factors including elevation, aspect, and microtopography. This paper demonstrates that on the glacial foreland at Storbreen, Jotunheimen, Norway, chemical weathering and associated soil development trends show significant elevational influences. We sampled soils at shallow depths (0–1, 1–5, and 15–20 cm) at two sites on a moraine dated to 1750 at its elevational extremes of 1155 m (site L) and 1385 m (site H). The two moraine sites also differed developmentally from an adjacent 9000-year-old surface (site T) at an intermediate elevation, 1205 m. Analyses were conducted on the fine-earth fractions. Extractable elemental composition exhibited detectable differences between the same-age soils at different elevations with the lower site L tending to have measured parameters intermediate between the high site H and the older site T. Weathering, as indicated by mineralogy, was more pronounced at the 9000-year-old site T and least evident at the high elevation site H. In addition, elevation under the conditions of the field research may inhibit pedogenesis as indicated by the chemical data. Site H, for example, showed little variation with depth and had in general, less organic matter accumulation, smaller C:N ratio, greater pH, and lesser amounts of the measured extractable elements than the soil at site L. Site T generally had smaller pH and larger levels of the measured elements than the other sites. It was concluded that elevation has a significant control on weathering and pedogenesis that may mask the effects of age in this cold and wet environment.     

FANTASY,GEOGRAPHY, WAGNER,AND OPERA*

ABSTRACT. Wilhelm Richard Wagner fused fantasy based on epic and lore with seamless scores, using landscapes and urban images to forge spatial order on stage. As a footloose composer-conductor, Wagner was considered a globetrotter for his time, and from trans-European tours he drew inspiration for numerous stagings. Nine of his operas have rustic pastoral settings, with actors silhouetted against geological formations, forests, vistas of undulating terrain for pilgrimages, or raging seas, all visually believable scenery. Rienzi and Die Meistersinger von Nürnberg are urban in setting, whereas Die Feen and Das Liebesverbot are set in a castle-like format.