滇东晚二叠世煤田中火山灰蚀变粘土岩夹矸(TONSTEIN)的锆石特征

本文就滇东晚二叠世含煤沉积中同沉积火山灰蚀变粘土岩夹矸和正常沉积粘土岩的锆石进行了统计学和形态学研究.该两种不同成因类型的粘土岩中锆石含量及形态面貌有显著区别.tonsteins中锆石形态参数统计规律因层位而异;同层位tonstein的锆石含量和形态参数在平面上呈有规律地变化.系统研究含煤建造剖面上各类岩石(包括tonsteins)中的锆石特征,能够用以确定物质来源、性质、成因以及以此为基本建立正常地层层序并精确对比层位,因而具有理论和实用意义.     

滇东晚二叠世煤田中火山灰蚀变粘土岩夹矸(TONSTEIN)的锆石特征

本文就滇东晚二叠世含煤沉积中同沉积火山灰蚀变粘土岩夹矸和正常沉积粘土岩的锆石进行了统计学和形态学研究.该两种不同成因类型的粘土岩中锆石含量及形态面貌有显著区别.tonsteins中锆石形态参数统计规律因层位而异;同层位tonstein的锆石含量和形态参数在平面上呈有规律地变化.系统研究含煤建造剖面上各类岩石(包括tonsteins)中的锆石特征,能够用以确定物质来源、性质、成因以及以此为基本建立正常地层层序并精确对比层位,因而具有理论和实用意义.     

滇东黔西晚二叠世含煤沉积中火山灰蚀变形成的伊利石粘土岩夹矸

本文对广泛分布于滇东-黔西晚二叠世含煤沉积中粘土岩夹矸的岩石学、矿物学、化学组成和微量元素进行了研究。发现粘土岩夹矸的变种伊利石粘土岩夹矸(Illite-tonstein)在沉积盆地空间上成片分布,且与晚期成岩作用有明显的成因联系。粘土岩夹矸中粘土矿物构成与煤阶大体对应的关系,揭示了同沉积火山凝灰蚀变产物的后期变化趋势和规律。     

华北聚煤区火山灰蚀变粘土岩夹矸的研究

本文论述了火山灰蚀为粘土岩夹矸的层位和分布，对结构构造作了系统分类及命名，首次在我国粘土岩夹矸中发现了较广泛分布的铵云母，还有伊利石和纳云母。成因矿物标型特征的研究为探索原始物质提供了可信的证据。     

黔西晚二叠世煤地球化学性质变异及特殊组构的火山灰成因

运用仪器中子活化分析(INAA)、电感耦合等离子体原子发射光谱(ICP—AES)、X射线衍射(XRD)、带能谱仪的扫描电镜(SEM—EDX)及光学显微镜等手段，对黔西晚二叠世煤地球化学性质变异及其特殊组构的火山灰成因进行了研究。结果表明，贵州西部织金矿区9煤层中异常高含量的Fe(4．24％)、Cu(369．90μg／g)、U(49．6μg／g)、Mo(63．10μg／g)、Zn(33．97μg／g)等是来源于同沉积基性火山灰降落到泥炭沼泽中所致；高含量的Fe、Cu并非以通常意义的煤中硫化物状态存在；除煤中有机质和陆源碎屑外，发现了由火山灰、有机质和陆源碎屑所形成的煤层中的特殊组构，暂定名为沉碳质火山胶凝物，它是一种有机—无机高度混合物质，根据沉碳质火山胶凝物的形态特征和物质组成，厘定出6种组构类型，分别是：网状组构、细屑组构、基质组构、孔腔组构、均质组构和碎屑组构。     

滇东黔西地区陆相二叠—三叠系界线粘土岩特征

在滇东黔西地区，海相和陆相二叠－三叠系界线附近均有界线粘土岩存在。本文介绍了该区陆相界线粘土岩的特征，并探讨了其成因。这些粘土岩主要矿物成分为伊／蒙混层矿物（20％－80％）和高岭石（35％－80％），碎屑物中有锆石、磷灰石、六方双锥石英、其他类型石英和微球粒等。提出界线粘土岩中的物质主要是火山成因，也有正常沉积物的加入，可能还拌有撞击作用的影响。     

滇东黔西晚二叠世聚煤区潮坪沉积特征

滇东黔西晚二叠世聚煤区为整个华南地区重要的成煤区域。根据地质资料及工作实践,论述和总结了该区潮坪沉积特征及成煤规律。结果显示,本区潮坪体系特有的沉积构造十分丰富,主要有潮汐作用形成的单粘土层、双粘土层和潮汐周期层序、涨落潮沉积的二元韵律结构、扁平状和浑圆状泥砾、双向泥砾、递变式的潮汐周期层序和泥冲槽等;潮坪体系的沉积层序和平面砂体特征明显,潮沟砂体一般垂直于海岸展布,且常朝陆地方向分岔尖灭;潮坪环境在相对稳定的构造条件下,多形成广泛稳定的优质煤层,但潮沟或泻湖海湾等长期被海水侵漫的区域,常使下伏煤层的含硫量变高。指出潮坪体系是该区富集优质煤层的重要成煤环境之一。     

四川盆地晚三叠世火山灰成因粘土岩特征及其

研究了四川盆地晚三叠世含煤地层中火山灰成因煤土岩的分布特征，岩石学特征和地球化学特征，探讨了其成因。     

华北晚古生代煤系I／S间层粘土岩稀土元素地球化学特征

通过ICP和INAA方法对华北几个晚古生代煤田（煤矿区）的I／S间层粘中土岩样品进行了稀土元素（REE）地球化学特征研究。结果表明，无序间层粘土岩REE含量较低，并具中－－弱Eu正异常为特征；IS有序间层粘岩以REE含量高，中－－强Eu亏损为特征，两种I／S间层粘土岩的REE含量及特征均与NASC有所不同，物源分析表明，无序间层粘土岩主要由中性火山碎屑（岩）在原地蚀变、转化而成，而有序间层粘土岩则是由酸性岩蚀变而成。     

滇东早寒武世梅树村期浅色粘土岩层的地球化学特征和地质意义

滇东早寒武世梅树村期含磷岩系中出现的十多层浅色粘土岩层为酸性火山灰蚀变而成的变斑脱岩，它们是火山喷发事件和事件地层对比的标志。这些浅色粘土岩层中稳定微量元素Ｈｆ、Ｎｂ、Ｙ、Ｔｈ、Ｚｒ含量高于非火山成因的粘土，而Ｆｅ、Ｎｉ、Ｃｏ、Ｃｒ含量低于筇竹寺组泥岩。ＴｉＯ２／Ａｌ２Ｏ３、Ｚｒ／Ｈｆ、Ｔｉ／Ｔｈ比值属于酸性岩浆范围，球粒标准化稀土元素配分模式和具中至大的Ｅｕ负异常类似于花岗岩稀土配分模式。岩浆判别图指示了梅树村期变斑脱岩具板内花岗岩位置的亚碱性流纹岩和粗面岩岩浆亲缘性。变斑脱岩在地层序列上和区域上分布表明扬子地台西缘早寒武世初期火山活动频繁，火山喷发事件与古大陆解体和板内拉张构造运动有关。     

滇西羊拉矿区火山岩痕量元素地球化学

云南省德钦县羊拉乡的羊拉铜矿,地处金沙江缝合带中段。矿区地层划分为羊拉岩组和里农岩组,矿区火山岩由两个岩组的火山岩组成,主要沿金沙江西侧分布,构成一条区域性出露面积达１５０ｋｍ２、总厚度约４００ｍ的火山岩岩带。羊拉岩组玄武岩锆石ＵＰｂ不一致线的下交...     

Chronology and Geochemistry of Volcanic Rocks in the Cretaceous Suifenhe Formation in Eastern Heilongjiang, China

Zircon U-Pb ages and geochemical data of volcanic rocks in the Suifenhe Formation in eastern Heilongjiang Province are reported, and their petrogenesis is discussed in this paper. The Suifenhe Formation mainly consists of basalt, andesite, and dacite. Zircon from andesite and dacite are euhedral in shape and show typical oscillatory zoning with high Th/U ratios (0.18-0.57), implying its magmatic origin. Zircon U-Pb dating results by laser ablation inductively coupled plasma mass spectrometer (LA-ICP-MS) indicate that the 206Pb/238U ages of zircons from andesite range within 105-106 Ma, yielding a weighted mean age of 105.5±0.8 Ma (n=14), and that 206Pb/238U ages of zircons from dacite are between 90-96 Ma, yielding a weighted mean age of 93.2±1.3 Ma (n =13). The volcanic rocks from the Suifenhe Formation are subalkaline series and show a calc-alkaline evolutionary trend with SiO2 content of 47.69%-65.47%, MgO contents of 1.42%-6.80% (Mg#= 45-53), and Na2O/K2O ratios of 1.83-3.63. They are characterized by enrichment in large ion lithophile elements (LILE) and light-rare-earth elements (LREE), depletion in heavy rare earth elements (HREE) and high field strength elements (HFSE) (e.g., Nb, Ta, Ti), and low initial 87Sr/86Sr ratios (0.7041-0.7057) and positiveεNd(t) values (039-4.08), implying that they could be derived from a depleted magma source. Taken together, these results suggest that the primary magma of the volcanic rocks might originate from partial melting of the mantle wedge metasomatized by fluids derived from subducted slab under a tectonic setting of active continental margin.     

Geochemistry of Archaean Volcanic Belts in the Eastern Goldfields Region of Western Australia

Volcanic belts in the Kalgoorlie-Norseman district of the EasternGoldfields region of the Western Australian Shield are dominatedby monotonous sequences of metamorphosed tholeiitic pillow basaltsshowing little vertical or lateral variation. These meta-basaltsare chemically similar to Archaean tholeiites from Canada andSouth Africa and are characterized by their low content of K,Rb, and Sr and low Fe₂O₂/FeO ratios. There is little evidenceof major cyclic compositional trends within the volcanic belts,with both major and trace elements showing limited dispersion.An undifferentiated, uncontaminated source of basaltic materialwas available throughout the development of thick volcanic pilesin the region.     

滇黔交界地区玄武岩铜矿流体包裹体地球化学特征

为了探讨玄武岩铜矿成矿流体的特征,对滇黔交界地区峨眉山玄武岩铜矿3个成矿期次铜矿石中石英和方解石的气液包裹体进行了激光拉曼成分研究和均一温度、盐度测定,对古石油包裹体通过荧光显微镜进行了成分鉴定。结果表明：第1、2期次成矿流体主要为盆地卤水,其气液包裹体气液比小（一般5%～10%）,w（NaCl）为8%～22%,气相为甲烷,液相为水,无子晶及液相CO2,均一温度为80℃～260℃;第2期次成矿流体除盆地卤水外,还有以古石油为代表的有机流体,古石油包裹体由液态烃、固体沥青和气相组成,均一温度变化大（30℃～290℃）,液态烃以荧光性强的芳烃为主;第3期次成矿流体具有大气降水成因,其气液包裹体气液比一般为5%～10%,w（NaCl）〈4%,无子晶及液相CO2,均一温度140℃～270℃,但以小于200℃为主。从第1期次到第3期次,成矿流体盐度逐渐降低,特别是第3期次的盐度非常低,但温度变化不明显。本区最重要的自然铜沉淀富集成矿是第2期次不同性质成矿流体混合或成矿流体与有机流体混合、有机质的还原的结果。     

黔西滇东地区早三叠世早期植物化石研究的新进展

早三叠世华南地区海相沉积广为发育.陆相沉积仅在海南岛和康滇古陆的东缘零星分布,植物化石非常罕见.报道的植物化石采自黔西滇东陆相岔河剖面宣威组顶部、海陆过渡相密德剖面和土城剖面的卡以头组下部,与晚二叠世晚期宣威组植物化石比较,植物类型单调,保存较破碎,共计14属31种,其中以Annalepis为主的石松纲5种;楔叶纲5种...     

Geochemistry, Petrogenesis and Geodynamic Relationships of Miocene Calc-alkaline Volcanic Rocks in the Western Carpathian Arc, Eastern Central Europe

We report major and trace element abundances and Sr, Nd andPb isotopic data for Miocene (16·5–11 Ma) calc-alkalinevolcanic rocks from the western segment of the Carpathian arc.This volcanic suite consists mostly of andesites and dacites;basalts and basaltic andesites as well as rhyolites are rareand occur only at a late stage. Amphibole fractionation bothat high and low pressure played a significant role in magmaticdifferentiation, accompanied by high-pressure garnet fractionationduring the early stages. Sr–Nd–Pb isotopic dataindicate a major role for crustal materials in the petrogenesisof the magmas. The parental mafic magmas could have been generatedfrom an enriched mid-ocean ridge basalt (E-MORB)-type mantlesource, previously metasomatized by fluids derived from subductedsediment. Initially, the mafic magmas ponded beneath the thickcontinental crust and initiated melting in the lower crust.Mixing of mafic magmas with silicic melts from metasedimentarylower crust resulted in relatively Al-rich hybrid dacitic magmas,from which almandine could crystallize at high pressure. Theamount of crustal involvement in the petrogenesis of the magmasdecreased with time as the continental crust thinned. A strikingchange of mantle source occurred at about 13 Ma. The basalticmagmas generated during the later stages of the calc-alkalinemagmatism were derived from a more enriched mantle source, akinto FOZO. An upwelling mantle plume is unlikely to be presentin this area; therefore this mantle component probably residesin the heterogeneous upper mantle. Following the calc-alkalinemagmatism, alkaline mafic magmas erupted that were also generatedfrom an enriched asthenospheric source. We propose that bothtypes of magmatism were related in some way to lithosphericextension of the Pannonian Basin and that subduction playedonly an indirect role in generation of the calc-alkaline magmatism.The calc-alkaline magmas were formed during the peak phase ofextension by melting of metasomatized, enriched lithosphericmantle and were contaminated by various crustal materials, whereasthe alkaline mafic magmas were generated during the post-extensionalstage by low-degree melting of the shallow asthenosphere. Thewestern Carpathian volcanic areas provide an example of long-lastingmagmatism in which magma compositions changed continuously inresponse to changing geodynamic setting. KEY WORDS: Carpathian–Pannonian region; calc-alkaline magmatism; Sr, Nd and Pb isotopes; subduction; lithospheric extension     

滇西施甸地区卧牛寺组火山岩的地质时代及喷发环境

前人将施甸地区卧牛寺组火山岩与北部保山地区卧牛寺组火山岩等同起来,认为是海相喷发的产物。本次调查工作揭示,施甸地区卧牛寺组缺乏沉积夹层,与北部保山地区卧牛寺组火山岩喷发环境存在明显差异,其岩石学、地球化学、宏观地质特征均表明,施甸地区卧牛寺组火山岩具大陆溢流相喷发机制,为陆相喷发产物。同时,年龄测定结果（264 Ma）及其与下伏和上覆地层的接触关系表明,卧牛寺组火山岩的喷发时期为早二叠世,为卧牛寺组地质时代的确定提供了重要依据。     

滇西腾冲-梁河地区花岗岩锆石稀土元素组成和U-Pb同位素年龄

在详细的区域地质调查基础上,对滇西腾冲-梁河地区花岗岩的锆石进行了阴极发光观察,并通过LA-ICP-MS分析了其稀土元素组成和U-Pb同位素年龄。花岗岩中大部分锆石具有振荡环带,锆石稀土元素表现为亏损轻稀土、阶梯式富集重稀土、强烈正Ce异常及强烈负Eu异常,表明锆石为典型的岩浆锆石。花岗岩（D0053）锆石的²⁰⁶Pb/²³⁸U加权平均年龄为（127.9±1.0） Ma (MSWD=2.9,27个点),花岗岩（D4310）锆石的²⁰⁶Pb/²³⁸U加权平均年龄为（58.3±0.5） Ma (MSWD=1.8,21个点),表明腾冲-梁河地区存在大量早白垩世和早第三纪花岗岩浆活动,它们是特提斯演化过程的岩浆响应。     

贵州遵义地区煤矸石元素地球化学特征及其综合利用信息

煤矸石的元素地球化学特征对煤矸石综合利用途径有着重要约束。贵州是我国主要的产煤区,煤层主要分布在六盘水、毕节、遵义等地区。本文借助ICP-MS、XRD和XRF等现代分析方法,对遵义地区煤矸石矿物学和元素地球化学特征进行了系统研究。结果显示,煤矸石矿物成分主要为石英和粘土等富硅矿物,并含一定量的锐钛矿和黄铁矿等金属矿物。煤矸石主量成分以富Al2O3(14.26%～33.16%)和TiO2(1.05%～2.35%)为特征,微量成分以富Z(r39.5×10-6～1060×10-6)、Nb(3.54×10-6～101×10-6)、Ga(3.74×10-6～45.4×10-6)和Sr(22.6×10-6～1940×10-6)等为特征,具有重要的综合利用价值。综合分析显示,煤矸石中具有综合利用价值的稀贵金属与其所含的锐钛矿密切相关。