MORPHOLOGY, INTERNAL STRUCTURE, AND ORIGIN OF GLAUCONITE PELLETS

Glauconite pellets exhibit considerable variety in morphology and internal structure. Recognized morphological types are: (1) ovoidal or spheroidal; (2) tabular or discoidal; (3) mammillated; (4) ellipsoidal; (5) vermicular; (6) composite; and (7) fossil casts, internal molds, or replacements. Types of internal structures include: (1) random microcrystalline, (2) oriented microcrystalline, (3) micaceous, (4) organic (?) replacements, (5) coatings on detrital grains, and (6) fibroradiated rims. These characteristics can be used to interpret the origin and/or subsequent history of pellet types. Suggested origins include: (1) chemical precipitation, (2) expansion and alteration of detrital mica, (3) alteration of fecal pellets, (4) alteration of clay fillings of fossil tests, (5) mechanical aggregation, and (6) chemical replacement. Not all glauconite pellets exhibit diagnostic characteristics with regard to their genesis. Original morphologies may be obscured by abrasion (reworking) prior to final burial. Internal structures may be changed by recrystallization or other diagenetic processes. It is concluded that glauconite pellets have multiple origins. They can form from several different parent materials and by several different processes. Frequently, however, characteristics which might reveal the original nature of the pellets have been lost during reworking and diagenesis. Inasmuch as glauconite occurrences differ in kind and variety of pellets, recognition of pellet types and their distribution is potentially useful for stratigraphic correlation or environmental determinations.     

IMPACT BRECCIAS AND IMPACTITES OF THE KARA AND UST'-KARA ASTROBLEMES

Seventeen upper-mantle ultramafic xenoliths from the Lower Quaternary Tal Khodr Imtan cinder cone in southern Syria have revealed a dominant protogranular texture of nine spinel lherzolites, two spinel harzburgites, four spinel dunites, one spinel olivine websterite, and one spinel clinopyroxenite. The lherzolites, harzburgites, and dunites contain Cr-diopside and brown-red picotite, with a basanitic host rock; the websterite and clinopyroxenite contain Ti-Al-augite and Cr-hercynite. A lherzolite to dunite depletion trend is shown in the abundance of intermediate- and lightrare-earth elements (IREE and LREE) and from analytical data of dunitic olivine, with Ca, Al, Fe, Cr, and Si being the most depleted elements. The depletion probably resulted from successive partial melting. The scoriaceous basanite shows enrichments in REE and trace elements from a plume; the basanitic coating (around ultramafic xenoliths) increases in Mg/Mg+Fe⁺² and concentrations of Al₂O₃, TiO₂, and Na₂O by contamination from peridotitic olivine, and also from eclogite-gabbro and nephelinite near the bottom of the rifted crust.

Differences in the REE and trace-element concentrations among the peridotite xenoliths, the basanite host rock, and websterite indicate at least three different depths for their parent sources. The ultramafic inclusions in the basanitic host rock, as well as xenoliths in a carbonatite dike, suggest a deeper source for the carbonatite magma. At least part of the enrichment of the plume probably was accomplished by the subducted Tethys oceanic crust, suboceanic litho-sphere, and eclogite-gabbro. The thick plateau basalt in southern Syria indicates heavy and deep fracturing, and the extrusions of successive magmas from the upper mantle created a stretching and thinning in the continental crust. The proximity of this plateau basalt area to the Dead Sea-Jordan River Valley Rift, together with the source of the ultramafic xenoliths, points to a possible close relationship between the Red Sea Rift and the fracturing (offshoot rifting) in southern Syria.     

青藏高原北部沱沱河—格尔木地区的地壳结构和深部作用过程

通过对沱沱河—格尔木地区地震测深资料的重新解释，给出了该区地壳的二维速度分布剖面及Q值分布。上地壳横向速度结构具有明显的分区性。该分区范围大体与“亚东—格尔木项目”中所划分出的地体相一致。地震资料为本区划分地体提供了佐证。本文讨论了地体的拼合、碰撞的深部作用过程。认为上地壳的逆冲、叠覆，中、下地壳的挤压增厚，以及岩浆的贯入，壳幔物质的混合导致了青藏高原的隆升。     

海水养殖珍珠表层微形貌的结构研究--以广西防城养殖珍珠为例

海水养殖珍珠的表层微形貌呈现以文石晶体及壳角蛋白膜为结构单元组成的按一定方式排列的层状或阶梯状的结构或形态。单元结构的生长方式符合“隔室效应”原理。表层结构中文石的结晶度、结构有序度及壳角蛋白膜厚度是珍珠光泽强度与明亮度的决定因素 ,并影响珍珠的透明度、伴色及体色。     

MORPHOLOGY AND STRUCTURAL HISTORY OF THE SOUTHEASTERN CRIMEA

The Tuak and Sudak anticlinoria located upon the eastern periclinal closure of the Crimean meganticlinorium are complicated by a folding of the higher order. According to their size and morphological structures, the folds are subdivided into several types. The small linear disharmonic folds in the Upper Triassic, Lower- and Middle Jurassic deposits within the cores of the above anticlinoria are followed by an elongated brachy-folding within the Upper Jurassic deposits upon the saddle of the Sudak-Yanyshar anticlinorium. The distribution of individual folding types corresponds to the history of fold formation. It depends on the tectonic movement environments, the physical properties of the rocks and other causes. The study of conditions controlling the formation and development of structural forms is conducted on the basis of a structural-facies method. The increase of sedimentation thicknesses and the replacement of coarse terrigenous materials by finer sediments towards the axial parts of the synclines, are evidence of the fact that the folding development was contemporaneous with sedimentation during a prolonged period. Folding, however, proceeded at irregular times.

The linear folding within the Tavridian shales upon the saddle of the Tuak anticlinal zone developed under conditions of active positive movements during pre-Bajocian stage of folding. In addition to linear folds, elongated brachysynclines appeared within the areno-argillaceous deposits upon the saddle of the Sudak-Yanyshar anticlinal zone during pre-Oxfordian time. A further growth and isolation of individual folds took place in an environment of considerable tectonic movement intensification during the Oxfordian and Kimmeridgian stages. The most energetic folding movements took place during the pre-Tithonian phase of folding. A sharp uplift of the eastern part of the Sudak- Yanyshar anticlinorium saddle called forth the appearance of crescentic, elongated folds. Within the Meganom downwarping folds developed during the Jurassic under conditions of continuous plunging.

The development of the principal structural units is connected with manifestations of deep-seated tectonic processes. The folding located upon the Sudak-Yanyshar anticlinorium saddle is classified as forced folds. The prolonged growth of the folds was accompanied by a forcing up of argillaceous materials into the anticline saddles. The plastic shift of Middle Jurassic clays from under the subsiding synclines toward the continuously eroding anticline saddles, i. e. towards areas of free material outflow, took place under conditions of continuous intensification of the tectonic movement and a continuous increase of load upon the subsiding areas. The supply of plastic material into the anticline saddles began during the Oxfordian stage and continued up to the present. This process proceeds in an environment of further expansion of the Sudak-Yanyshar anticlinorium. In connection, however, with a general weakening of the tectonic movements and an increase of the argillaceous material metamorphization the forcing up of the latter gradually subsides.—Auth.English summ.     

高岭石-多水高岭石矿物晶体形态与演化

通过对我国南方许多风化型高岭土矿床研究查明,在表生条件下形成高岭石-多水高岭石矿物的基本因素是决定于风化母岩的岩性和水介质的物化性质。水介质的物化性质又明显地受到风化母岩的岩性类型和结构构造、动力裂隙的发育程度、围岩的稳定性和透水性、气候、地形地貌和植被等因素的综合性制约。     

大陆边缘反S状造山带三维模式兼论青藏高原结构与隆升

文中根据北美大陆西南边缘造山带的构造地貌及新构造运动特征, 建立了反S状大陆边缘造山带的三维构造力学模式, 指出阿拉斯加地区为弧形右旋剪切隆升造山带; 科迪勒拉造山带为直线右旋走滑造山带; 马德雷山以南, 延至加勒比海为一左旋沉降`旋扭沟-弧-盆系统'。以此模式检验欧亚大陆南缘造山带, 确定从阿尔卑斯经扎格罗斯、喜马拉雅至印度尼西亚蜿蜒曲折的山链是由四个反S状造山带连锁而成, 导致它们的分解为四个构造体系的原因, 与南半球冈瓦纳大陆裂解有关。依据上述的区域构造规律, 作者认为青藏高原内部结构的原型为旋扭沟-弧-盆系统, 属帕米尔—喀喇昆仑—喜马拉雅反S状造山带尾弧的组成部分。后经印度板块俯冲、青藏—三江—印度尼西亚反S状造山带头部弧右旋隆升两组动力系统叠加结果。     

大陆岩石圈构造与地球动力学

从简述大陆岩石圈与地球动力学研究的基本现状和存在的问题入手,提出了今后十年岩石圈构造研究的五个重点课题,即岩石圈的流变性、岩石圈界面的性质、软流圈、岩石圈中的薄层及波导、岩石圈构造的横向变化。同时,讨论了震源及震源环境的研究,列出了今后的重要研究课题,最后论述了深部构造与中国大地构造的关系。     

蒙脱石晶体结构和水结构的矿物物理特征

本文利用矿物物理研究方法对我国内蒙、浙江、甘肃等地的钙基、钠基、镁基蒙脱石的物质成分、晶体结构和层间OH,H_2O的排布结构进行了研究,并获得下列结论: 1.由X衍射和拉曼分子光谱分析深入研究了蒙脱石阳离子配位体结构特征,提出其空间群为C_(2/m) 型。 2.建立了蒙脱石水结构模式,有3种主要类型:①层间大阳离子附近的束缚态水分子;②层间无大阳离子位置上的非束缚态水分子;③颗粒表面依靠氢键相连的水分子集合体。 3.利用群理沦,提出了蒙脱石OH～-的振动模式,由振动分析指出蒙脱石中OH～-具有12个振动模式。     

蒙脱石晶体结构和水结构的矿物物理特征

本文利用矿物物理研究方法对我国内蒙、浙江、甘肃等地的钙基、钠基、镁基蒙脱石的物质成分、晶体结构和层间OH,H_2O的排布结构进行了研究,并获得下列结论: 1.由X衍射和拉曼分子光谱分析深入研究了蒙脱石阳离子配位体结构特征,提出其空间群为C_2/m型。 2.建立了蒙脱石水结构模式,有3种主要类型:①层间大阳离子附近的束缚态水分子;②层间无大阳离子位置上的非束缚态水分子;③颗粒表面依靠氢键相连的水分子集合体。 3.利用群理论,提出了蒙脱石OH~-的振动模式,由振动分析指出蒙脱石中OH~-具有12个振动模式。     

河西金矿构造控矿特征及成因机制初探

河西金矿床成矿构造位置独特,矿体复杂.文章从控矿构造成因人手,研究了河西金矿床控矿构造的形成、发展和演化,指出了河两金矿床控矿构造系统是在不同于主应力场的局部应力场作用下形成的,不同方向的矿体也是在同一时期、同一应力场作用下,在不同性质的构造裂隙的引张部位形成的.     

冀北辽西地区构造形迹的新认识

冀北辽西地区的盖层可分两个构造层，由燕辽复向斜和秦皇岛背形相互叠加，并相应发育两期推覆构造。复向斜范围包括内蒙古地轴和燕辽沉降带，是由长条形的3个背斜和2个向斜相间，及配套的EW向纵断裂、SN向横断裂和NE向、NW向的共扼断裂组成。著名的尚义一宽城一凌源一朝阳一北票断裂是复向斜及其次级背斜的轴部纵断裂，以南大岭组、窑坡组和北票组作为其裂隙充填物。燕山EW向断裂南北对冲现象是复向斜纵断裂放射状排列并向核部推覆的反映。秦皇岛背形以秦皇岛一凌源断裂为轴面，由复向斜的轴面褶皱而成，背形转折端在秦皇岛，呈相对上翘。本区NE向、NNE向断裂的叠加在区域上有不同的表现：冀北段NE向、NNE向褶皱叠加的结果使燕山段复向斜成为短轴褶皱样式，平面团呈NW向排列，符合Ramsay第一类褶皱干涉样式的第二种类型。复向斜的形成机制完全符合纵弯褶皱作用下岩石的变形原理，是西伯利亚板块和华北板块碰撞的结果；秦皇岛背形的形成是后期太平洋板块俯冲在欧亚板块之下所致。     

铁木里岩群特征及区域构造分析

燕山构造运动时期,由于区域右型剪切应力的作用,使北东向板岭下断裂继续作右行剪切运动,在其南东盘派生出思顺环状构造,并带动环状构造作左行旋转运动,从而在铁木里地区形成了一个应力拉张区,为铁木里岩群的侵位创造了良好的构造环境。拉张应力作用以“脉动”方式多次进行,每一次“脉动”拉张,随之出现一次岩浆侵位（或隐爆）,形成了由隐爆角砾岩体→粗安玢岩体→正长斑岩体→黑云母花岗岩体从西向东的空间定位格局。     

ASPECTS OF THE STRUCTURE AND HISTORY OF SUTURE ZONES: THE CAUCASUS

Age of Paleogene deposits of flora and fauna in the southern Siberian Platform (Pg2³ - Pg3¹), determined solely on the basis of palynological data was determined in 1962 in the sporepollen laboratory of the Irkutsk Geologic Board. These data indicate that at the time the sediments were formed the dominant vegetation consisted of typically subtropical, coniferous broad-leaf forests. — IGR Staff.