苏联境内含油气沉积盆地及其地球动力学特征

苏联境内含油气沉积盆地地球动力学特征型式多样、变化较大,几乎包括现今已认识到板块构造分类的所有类型.第一种类型盆地位于陆内埋藏裂谷海槽一坳拉谷中,上裂谷盆地和台坳稍晚形成并叠置其上.这些盆地长轴延伸方向既可以平行于大陆边缘,也可以垂直于它,后者形成一三角形分枝.Pripyat′－Dnieper－Donets裂谷系是第一亚类的典型代表,它位于东欧地盾南部,形成于中一晚泥盆世和早石炭世,较后,乌兰克台坳覆于其上.巨型西西伯利亚盆地,尽管位于年轻地台内,但也可看成是同样类型,因为其基底发育一条近南北向二叠—三叠纪及更老(北部)的裂谷系.此种亚类更具代表性的是Barents海盆地,它在泥盆—二叠纪时为裂谷阶段,三叠纪时开始成一个向斜盆地.     

THE GEOCHEMISTRY CHARACTERISTICS OF BLUESCHIST IN THE GANGMAR AREA, QIANGTANG BLOCK, TIBET

THE GEOCHEMISTRY CHARACTERISTICS OF BLUESCHIST IN THE GANGMAR AREA, QIANGTANG BLOCK, TIBET     

热力学在矿床中的应用(上)

在有些沉积的硫化物矿床中,如含铜页岩中,金属富集具有Cu—Pb--Zn顺序(Weepohl)的层状分带性,有的地方矿化分带,正如Rentzsch所述,穿切了岩石氧化形成层。在这两种情况下,矿化分带顺序都相当于从更为氧化改变到更为还原条件。据Rentzsch(1974),矿物以次为:(1)赤铁矿(2)辉铜矿(3)斑铜矿—辉铜矿(4)斑铜矿(5)斑铜矿—黄铜矿(6)黄铜矿—黄铁矿(7)方铅矿—闪锌矿—黄铜矿(8)方铅矿—闪锌矿(9)黄铁矿。     

国际矿物学协会新矿物及矿物命名委员会(IMA CNMMN)多型后缀规范化

国际矿物学协会新矿物及矿物命名委员会(IMA CNMMN)已经出版了关于矿物命名的若干准则,其中包括对矿物多型的命名法(如Nickel和Mandarino,1987)。从根本上说,多型名称是由在矿物名(root name)后附加数字和字母,并将数字和字母用连字符(-)与根矿物名连接起来而形成。附加的数字部分代表层的周期(layering periodicity);而字母部分以斜体书写,代表晶系。举例来说,Wurtzite-4H(纤锌矿-4H)是具有4倍于纤锌矿母体(wurtzite parent)c轴长度的同期之六方纤锌矿多型。     

黔西南高砷煤的分布及地球化学特征研究

根据野外地质特征结合中子活化成分分析结果,探讨了黔西南高砷煤的分布特征、影响因素和某些地球化学特征。高砷煤严格受构造（褶皱和断层）、地层（二叠系龙潭组）、沉积相（海陆交互相）的控制,分布于平行北斜长轴的断层两侧,愈靠近断层面砷的含量愈高。砷在煤中的分布极不均匀,即使同一煤层变化也极大。在时空关系与元素组合上高砷煤与区内卡林型金矿密切相关。     

1977-1989中国冰川地质研究的新取向

中国的传统冰川地质学研究是同李四光的名字紧密相连的。１９７７年以后，现代沉积学的原理和方法在中国冰川地质学的研究中得到了广泛的应用。中国西部的自然条件易于形成突发性的泥石流。区别冰川沉积物和泥石流沉积物在沉积学上的异同是冰川地层学研究中的关键问题。解决有关中国西部冰川扩张的次数和范围等重大问题，有待于冰川地层学和冰川地貌学新手段的综合运用。     

全球寒武系年代地层再划分的新建议

介绍最近提交国际地层委员会寒武系分会的全球寒武系年代地层划分方案 ,划分为 4个统级单位和 10个阶级单位 ,同时提出划分芙蓉统的两个新点位 ,即球接子类三叶虫 Agnostote orientalis和 L otagnostusamericanus的首现。     

Single zircon evaporation ages: Evidence for the Mesoproterozoic crust in the southeastern Nigerian basement complex

The Ukwortung area of the Obudu Plateau exposes high-grade metamorphic rocks of upper amphibolite to granulite facies. Zircon grains from three locations of Southwest Obudu Plateau were dated by the Pb-Pb dating method. This single zircon radiometric dating method confirms the occurrence of Mesoproterozoic crust in the southeastern Nigeria basement complex. The pyroxene gneiss (granulite facies) sample from Biereberi near Ukpe yielded a mean age of 2061.4±0.4 Ma, suggesting the presence of Paleoproterozoic crust. The combined 207Pb/206Pb ratios from the garnet-biotite gneiss in the area gave a mean age of 1794.4±0.4 Ma. This further confirms the pres-ence of Paleoproterozoic crustal components within the Obudu Plateau. The Mesoproterozoic (1548.8±0.5 Ma) and Neoproterozoic (619.8±0.9 Ma) ages were obtained from two populations of zircon grains from the leucogranite in Okordem, Southwest Obudu. These "signatures" collaborate the occurrence of Mesoproterozoic ages in the Afar region and Cameroon basements along with the southeastern Nigerian basement complex, constituting the major portion of the West Central African mobile belt. The zircon age of 1794.4±0.4 Ma may probably be the maximum depositional age of the meta-sediment (garnet-biotite gneiss) and the age of 1548.8±0.5 Ma may be interpreted as the time of emplacement of the granitoid. The Neoproterozoic age (619.8±0.9 Ma) probably records the metamorphic event that was prevalent during the Pan-African period and thus affected the area.     

Multifractal Simulation of GeochemicalMap Patterns

INTRODUCTIONThe mathematical modeling of geochemical data continuesto present an important challenge to earth scientists. Basically,the available data are 2-dimensional realizations of 3dimensional patterns, which are the results of one or more genetic processes that usually are poorly understood. It may bedifficult to project from the observations into the rock mass. Inthis paper, multifractal modeling is advocated as a methodologyto characterize geochemical patterns. If a geochemical pa…