冀东某地原生红刚玉矿床地质特征

冀东某地原生刚玉矿床具有埋藏浅,刚玉个体大、微红至暗红色、半透明至不透明等特点,经人工改善可生产低档红宝石。本文主要介绍该矿床的刚玉形态特征、物理性质、晶体结构、包裹体特征及矿床形成的地质条件。研究认为,本矿床应属深熔型混合岩化作用成因,即“混合岩型”刚玉矿床。     

河北阜平起区刚玉宝石矿床研究

本文在区域地质背景的基础上,介绍了阜平隆起区刚玉宝石矿床（点）的地层分布、构造控制、含矿岩石、矿体产状等特征,以及刚玉宝石的矿物学简要特征;并在大量野外产状及岩石结构构造调查研究的基础上,根据作者矿床矿物学研究的证据,首次提出并证实此类型矿床属深熔型混合岩化作用成因,即“混合岩型”。     

昌乐地区新生代碱性玄武岩中刚玉、尖晶石巨晶岩相学、矿物化学特征

山东昌乐蕴含中国最大的宝石级刚玉—蓝宝石矿床。昌乐刚玉巨晶与玄武岩界限截然,边缘圆化,沿巨晶溶蚀圆化的边缘发育富铝的尖晶石和钛磁铁矿反应环边,显示其为深源捕虏晶的岩相学特征。对刚玉等巨晶及其反应边矿物进行岩相学、电子探针和LA-ICP-MS(Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry)分析能有效揭示其成因及演化历程。昌乐刚玉2组样品(CL-1和CL-2)矿物化学和关键元素特征及Ga/Mg、Cr/Ga、Fe/Ti、Fe/Mg等关键元素比值显示为岩浆型来源,而CL-2组样品明显叠加了后期熔体交代作用的特征。反应边尖晶石具刚玉巨晶向尖晶石巨晶过渡的成分特征,关键元素特征指示两者具强烈亲缘性,尖晶石巨晶是刚玉经历复杂交代作用的产物。昌乐刚玉呈现碱性熔体中结晶的化学成分特征,极有可能源于交代富集的地幔岩低度熔融形成的富铝的碱性熔体。     

湖北英山刚玉矿物学研究

湖北英山刚玉矿床是本世纪五、六十年代发现的,由于多种原因未能对其进行研究和开发利用。本文系统地研究了英山刚玉矿物学特征,测定了各种物性和参数,观测了刚玉包裹体;并利用电子探针、粉晶Ｘ射线分析、可见光谱等现代测试手段,较详细地分析了刚玉的化学成分、晶体结构及光谱特征,并进行了热处理实验研究。指出湖北英山产出的刚玉颗粒大,晶形好,颜色较浅,可用热处理的方法改成蓝色、黄色、肉红色,但由于裂隙发育,包裹体     

昌乐地区新生代碱性玄武岩中刚玉巨晶和伴生地幔岩捕虏体与熔体作用的研究

<正>西太平洋板块大陆边缘火山活动区的蓝宝石矿床,分布于塔斯马尼亚岛、澳大利亚的南部到东部、中国东部及俄罗斯东部(Graham,et al.,2008)。中国东部广泛分布的新生代碱性玄武岩中,山东昌乐蕴含中国最大的蓝宝石矿床,与蓝宝石/刚玉相伴生的地幔岩捕虏体为辉石岩和橄榄岩(董振信等,1999)。野外勘察发现,赋存蓝宝石/刚玉的层位往往含地幔橄榄岩捕虏体及矿物巨晶,而不含捕虏体的玄武岩层则不见刚玉,     

苏北红刚玉的发现及其矿物学特征

苏北某地超基性岩中,首次发现了红刚玉,少量已达宝石级。通过野外地质调查、矿物分析与测试和成因分析,该处产出的红刚玉是球斑状镁铝榴石二辉橄榄岩经热液蚀变后的产物,是一种新的红刚玉成因类型,从而为在苏北和鲁南地区寻找红宝石矿床拓宽了思路。     

新疆赛力格塔什刚玉矿床的初步研究

本文研究了西昆仑造山带南带的新疆赛力格塔什刚玉矿床,该矿床赋存于古老基底的变质 岩系中,含矿岩石为眼球状黑云母长石片麻岩,眼球部分由刚玉（中心）及钾长石（外围）组成,基体为 黑云母及钾长石。经岩石化学及微量元素等的研究表明,这是一个由贫硅富铝的沉积岩经高级变质 作用形成的矿床。     

巴塘县夏塞蓝刚玉矿地质特征

对蓝刚玉矿的地质特征、矿石类型及蓝刚玉特征作了简述,并对蓝刚玉的成因进行了初步探讨,提出了找矿标志。     

洱源盐井山刚玉矿床地质特征

通过1：5万区域地质调查工作，首次在云南省洱源县盐井山古元古代苍山变质岩中发现刚玉矿床，矿体产于苍山变质岩区，大涧口韧性剪切糜模岩带的变质镁铁岩外接触带，滑石片宕、云母片岩和伟晶岩脉中。矿石有伟晶岩型和滑石片岩型两类。     

太行山太古代阜平群中的刚玉、矽线石型矿床的成因

太行山太古代阜平群中刚玉矽线石型矿床,产于太古界阜平群地层中,矿体顶板围岩是长英质片麻岩.长英质片麻岩系流纹岩的变质岩.刚玉矽线石矿体系沉积变质而成.局部地段刚玉产出,除与原岩铝过饱和程度有关外,并与混合岩过程中钾交代作用有明显关系.含矿岩系的变质强度达到了矽线石角闪岩亚相.     

铁矿地质数据统计分布与铁矿成铁作用

从铁矿储量、品位等数据统计出发,分析各类铁矿品位的分布特点与规律,认为铁矿品位分布结构与该类铁矿的成矿条件,作用特点和机制有关;以系统数据及图表论证了单一成矿作用、一次成矿形成广泛分布的贫矿,再次或多期次（多阶段）和多种作用成矿的同位叠加,是使品位加富和形成工业富铁矿的关键;对各类铁矿品位高低、富矿规模力图进行合理的解释。     

从地洼成矿作用看中国某些优质锰矿的成因与远景

研究发现中国某些优质锰矿,属复成矿床,它们都是地洼成矿作用的产物。福建连城锰矿就是典型实例,类似矿床特别是复成风化锰矿,还见于闽西南-粤东北及湖南。滇东南一些锰矿,例如著名的斗南锰矿与白显锰矿的成因,也可能与地洼成矿作用有一定联系。分析对比了一些优质复成锰矿和一些较贫的复成锰矿的成矿地质条件。从地洼成矿作用可以看出中国某些优质锰矿的成因与远景。提出在中国东南地洼区、南北地洼区南端及云贵地洼区某些地方,寻找优质复成风化锰矿与复成菱锰矿—硫锰矿矿床是较有希望的。     

Features of Minerogenic Series Related to Continental VolcanicRocks in the Southeastern Coastal Area of China-A Case Study of the Daiyunshan-ShiniushanVolcanic Depression in Fujian

The Daiyunshan-Shiniushan volcanic depression in Fujian Province is situated in a volcanic belt of the southeast coastal area in China along the west Pacific Ocean. A new breakthrough has been made in the exploration of gold and silver ore deposits in recent years. The minerogenic series of the Daiyunshan-Shiniushan volcanic depression is discussed in this paper based on the analysis of major metallogenic types and factors. According to the study of enormous ore deposits and occurrences in the study area, two minerogenic series have been recognized: 1. Late Jurassic Au-Ag-Pb-Zn minerogenic series related to intermediate-acid, acid volcanic formations; 2. nonmetallic minerogenic series (pyrophyllite, alunite pearlite, andalusite, zeolite, corundum and so on) related to intermediate and acid volcanic formations. The division and study of the minerogenic series have revealed metallogenic and time-space distribution characteristics of the ore deposits in the volcanic belt of the southeast coastal area in Ch     

Study of melt inclusions in the Nezametnoye corundum deposit, Primorsky region of the Russian Far East: Petrogenetic consequences

Any and all proposed theories regarding the origin of sapphires are still very much open to debate. Critical inconsistency arises on the magmatic petrogenesis mechanism of sapphire crystal formation. The Nezametnoye Deposit is one of the most prospective placer deposits of jewelry grade corundum (sapphire) and zircon (jacinth) in Russia, and is known for its native and alluvial gold–wolframite–tin deposits. We present new data obtained from mineral and primary melt inclusions that are syngenetic to corundum. Electron microprobe analysis indicates that rutile, zircon, albite, zinc-bearing hercynite, columbite, and fluorite represent syngenetic mineral inclusions. Silicate melt inclusions are almost always associated with carbon dioxide inclusions; this correlation suggests that a heterogeneous fluid–melt system was present during corundum crystallization. Distinctive features of chemical composition of the inclusions, along with their agpaitic coefficients, indicate that corundum crystallization occurred from granosyenite melts. Primary carbon dioxide-rich inclusions form random groups, or are associated with melt inclusions. P–T conditions for corundum crystallization have been calculated as 780–820 °C and 1.7–3 kbar, based on data from primary carbon dioxide and melt inclusions.     

有机烃新方法在微细浸染型金矿床勘查评价中的应用——以陕西八卦庙特大型金矿床为例

有机质对金属元素的迁移、沉积、富集成矿有重要的作用.有机烃是有机质最终的裂解产物,具有很强的挥发性和穿透性.研究发现八卦庙金矿床有机烃与矿体金品位呈正相关关系,矿体的矿化富集中心也是有机烃的浓集中心.利用有机烃的这一特点可以进行隐伏金矿床的预测研究。     

CALCULATION AND PRACTICAL SIGNIFICANCE OF CATEGORY C2 GEOLOGIC RESERVES OF ORE DEPOSITS

Early ideas of rapid decrease in ore in grade and reserves with depth has led to considerable pessimism on calculation of C₂ reserves. Increased efficiency of mining methods, technology, and equipment has made it possible to mine many of the larger low grade deposits, lower grade deposits, and lower grade fringe deposits thereby greatly increasing the life of mines and mining districts. Most old mining districts have had productive lives far beyond known reserves at any one time. Ore zoning, except for unusual type of deposits, only rarely is of much practical importance in considering the depths of deposits. Geologic ore reserves of the C₂ category have been greatly underestimated in Russia. This category is not used for planning the immediate development of deposits and as a result there are many errors of planning and development. C₂ reserves should be calculated much more realistically than the present conservative practice and the results should be used in the proper economic development of ore deposits. - - J. A. Redden.     

A classification of gem corundum deposits aimed towards gem exploration

This classification of gem corundum (ruby and sapphire) deposits takes into consideration petrographic data, and the mode of genesis of the deposits. It is aimed at being practical and useful in the field, particularly for prospecting purposes.Deposits are classified into primary and secondary deposits. Primary deposits include igneous and metamorphic deposits. Igneous gem corundum deposits are rare and include sapphire-bearing syenites from Kenya. Emphasis is put on metamorphic deposits, that are subdivided into metamorphic s.s., metasomatic, and anatectic deposits. Many gem corundum deposits result from metasomatic processes. Small-scale metasomatism mostly involves desilication reactions between silico-aluminous rocks (pegmatites, gneisses, etc) and silica-poor rocks (ultramafites, meta-carbonates), and leads to the formation of limited-size deposits. Large-scale (diffuse) metasomatism is usually more difficult to characterize, and therefore is not separated from isochemical metamorphism in this classification. In metamorphic deposits, gem corundum results from transformation of an Al-rich and/or Si-poor protolith. Such deposits include ruby-bearing mafic granulites, ruby-bearing meta-limestones, and ruby/sapphire-bearing gneisses and granulites. An intermediate category includes anatectic deposits. Secondary deposits encompass sedimentary and volcanic (xenoclastic) occurrences. In sedimentary deposits, gem corundum occurs as clasts originating from other lithologies. In volcanic deposits, gem corundums are xenocrysts that have a range of origins.The proposed classification outlines geological environments favorable to the crystallization and distribution of gem corundum, thus facilitating prospecting and mining of this gemstone.     

北祁连错沟-小长干矿带铜锌矿床 物化探异常特征及找矿

错沟—小长干矿带是北祁连西段成矿区段内铜矿(点)分布最多的矿化密集区,区内已发现多处铜矿床及铜矿点。这些已知矿(点)大多为块状硫化物矿床,矿石品位较高,但矿体相对较小,寻找深部隐伏矿难度相应较大,文中以具有代表性的实例讨论区内矿床物化探异常特征及相应找矿问题。     

中国主要矿床数据库及其应用

新近完成的“中国主要矿床数据库”利用目前最优秀的高级关系数据库管理系统软件Ｆｏｘｐｒｏ２．５ｆｏｒ ｗｉｎｄｏｗｓ，以１９９３的底全国矿产储量统计表为基础，包含４０种主要常见矿产，共计大，中型矿床１９０２处，小型矿床３３８４处。数据库中不但载矿床的产地，坐标，储量，品位等矿床基本数据，而且还记录了矿床的类型，成因，成矿时代，围岩时代等矿床地质信息。