Based on studies of ore - bearing rocks and geochemistry, it is suggested that bauxite deposits in western Jiyuan were sediments in lake - environments after transgression when North China Block turned from peneplain in early Paleozoic to epeiric sea in late Paleozoic. Land covered by limestone, peneplain, humid climate, and flourish plants made karst lakes the best places for enriching and preservation of bauxite. The area covered by Permian strata in the northeast parts is good for prospecting.

文章在对含矿岩系岩石组合、地球化学分析的基础上,认为矿区铝土矿形成于华北地块从早古生代准平原状态向晚古生代陆表浅海过渡时期,早期海侵之后的陆地湖泊环境中.被碳酸盐岩覆盖、较小地形差异的陆地准平原状态,湿热的气候,繁茂的植物使得岩溶湖泊成为铝土矿富集和保存的有利场所.

There are many methods of studying and mapping of lithofacies paleogeography. This paper will describe the methodology of lithofacies paleogeography that was advocated by the present author, "Single factor analysis and comprehensive mapping method", with the example from the lithofacies paleogeographic study and mapping of Majiagou Group of Middle Ordovician of Ordos Region. By " single factor" , meant is the factors which can independently reflect certain aspects of the sedimentary environments. Single Factor Analysis and Comprehensive Mapping Method includes three steps. First, earnest petrological and petrographical study of each section should be made in order to obtain various firsthand complete and reliable quantitative and qualitative data, especially quantitative data, and to understand the characteristics of sedimentary environments of each stratigraphical interval in the section. Second, select those factors which can independently reflect some aspects of sedimentary environments ( i. e, single factors) from these quantitative data. And then the percentage content of each single factor in each section of the whole area, followed the requisite mapping unit, should be calculated to draw out various corresponding fundamental single factor maps. They are mainly various isoline maps. These fundamental single factor maps can quantitatively reflect different characteristics of sedimentary environments of the slratigraphical interval of the area. This is Single Factor Analysis. Third, Having synthesized these fundamental single facotr maps and combined with other quantitative and qualitative data and other regional geology data, through all-sided analysis and comprehensive judgement, with the dross discarded and the essential selected, the false eliminated and the true retained, the lithofacies paleogeographical maps of the mapping unit of the area can be compiled finally. This is Comprehensive Mapping. The core of this method is quantification. That is, on the basis of quantitative data, starting with analysis of quantitative fundamental single factor maps, then through comprehensive analysis and judgement, finally the quantitative lithofacies paleogeographical maps can be compiled. In these lithofacies pqleogeographicai maps, the determination of each plaeogeographical unit is based on definite quantitavtive data. This type of lithofacies paleogeographical maps is therefore no loger sketchy. This makes lithofacies pqleogeographicai maps developed into a quantitative stage. The following single factors are used in this paper: thickness, terrigenous materials, shallow-water grains, penecontemporaneous dolostones, gypsum, colors and so on. On the basis of various fundamental single factor maps of each formation of Majiagou Group of Ordos Region, combined with other quantitative and qualitative data, through all- sided analysis and judgement, the lithofacies paleogeographical maps of Majiagou Age I to VI of Middle Ordovician of Ordos Region wrer drawn out. The lithofacies paleogeography of Majiagou Age I may be generalized by following: Outside the lands wre flats (dolomite flats, etc); Inside the flats were lakes (gypsum salty lakes and gypsum lakes); Outside the flats were banks (embryonkc banks); Outside the banks were seas (open seas) and outside the seas were troughs (deep-water troughs). In Majiagou Age Ⅱ, the transgression was enlarged so that the whole area was open sea except three small lands. In the open sea there were some embryonic banks and penebanks scatterred. The lithofacies plaeogeography of Majiagou Age Ⅲ and Ⅴ were similar to that of Majiagou Age I. The lithofacies paleogeography of Majiagou Age n and IV were similar to that of Majiagou AgeⅡ. Generally speaking, form Majiagou Age Ⅰ to Ⅵ, three transgressions and three regressions appearred alternatively. They constructed a series of complete cycle of transgression and regression of triple assemblage and three similar, opposite and complementary, antithetical assemblages of lithofacies paleogeography in Majiagou Age of Middle Ordovic

古地理学及岩相古地理学的研究及编图方法较多,本文以鄂尔多斯地区天然气的主要产层中奥陶统马家沟群的岩相古地理研究及编图为例,阐述笔者倡导的岩相古地理学的方法论,即单因素分析综合作图法

在各基干剖面的地层学及定量沉 积学研究的基础上，根据作者倡导的“单因素分析综合作图法”，对中国南方二叠纪的岩相古地理进行了研究及编图。共编制出早二叠世的栖霞期与茅口期，晚二叠 世的龙潭期与长兴期的单因素基础图件２３幅，岩相古地理图４幅，比例尺均为１：２５０万。在这些岩相古地理图中，各一、二、三级岩相古地理单元的确定都有 定量的单因素数据为依据，这就使岩相古地理图和岩相古地理学发展到了定量阶段。各期岩相古地理的格局可概括为陆海相间，台盆相间，台中有盆，盆中有台，台 中有集、滩和礁，台盆间有斜坡。各期岩相古地理单元之间存在着明显的继承性、发展性和阶段性。这种定量的岩相古地理研究及编图为我国南方二叠系的油气

在各基干剖面的地层学及定量沉 积学研究的基础上，根据作者倡导的“单因素分析综合作图法”，对中国南方二叠纪的岩相古地理进行了研究及编图。共编制出早二叠世的栖霞期与茅口期，晚二叠 世的龙潭期与长兴期的单因素基础图件２３幅，岩相古地理图４幅，比例尺均为１：２５０万。在这些岩相古地理图中，各一、二、三级岩相古地理单元的确定都有 定量的单因素数据为依据，这就使岩相古地理图和岩相古地理学发展到了定量阶段。各期岩相古地理的格局可概括为陆海相间，台盆相间，台中有盆，盆中有台，台 中有集、滩和礁，台盆间有斜坡。各期岩相古地理单元之间存在着明显的继承性、发展性和阶段性。这种定量的岩相古地理研究及编图为我国南方二叠系的油气

The author initiated and adopted the single factor analysis and multifactor comprehensive mapping method as a new methodology of quantitative lithofacies palaeogeography in order to reconstruct quantitative lithofacies palaeogeography By meaning， single factors are the factors which can independently reflect some characteristics of sedimentary environments of a stratigraphic interval of a section in an area Presence or absence as well as high or low percentage of single factors can all independently and quantitatively reflect some characteristics of sedimentary environments of the interval of the section in the area, such as water depth, water energy, nature of the sedimentary environments, etc The thickness of the interval and its specific rock types, texture constituents, mineral composition, chemical composition, fossils and their ecological assemblages, etc, can all be taken as single factorsThe single factor analysis and multifactor comprehensive mapping method include three steps First, an indepth petrological and lithofacies study of each section, especially fundamental section, should be made in order to obtain various reliable firsthand qualitative and quantitative data, especially quantitative data, and to understand the characteristics of sedimentary environments of each interval of each section Second, according to the mapping units, from the quantitative data of each section, select those factors which can independently reflect the characteristics of sedimentary environments, ie the single factors Then the statistics of the percent contents of various single factors of each mapping unit of each section in the area are made Based on these percentage data, the various quantitative single factor maps, mainly isoline maps， are composed These single factor maps can quantitatively reflect the characteristics of sedimentary environments of the mapping unit of the area from different aspects This is the single factor analysis Third, through superimposition and synthesis of these quantitative single factor maps, combined with other quantitative and qualitative data of this mapping unit of the area, with the dross discarded and the essential selected, with the false eliminated and the true retained, the quantitative lithofacies palaeogeography map of the mapping unit of the area can be composed This is the multifactor comprehensive mappingThe core of this methodology is quantification That is, based on the quantitative single factor data of each section, starting from analysis of various quantitative single factor maps, through superimposition and comprehensive analysis and judgement, finally the quantitative lithofacies palaeogeography map can be composed In such palaeogeography map, the definition of each palaeogeographic unit is based on quantitative data and quantitative single factor maps Therefore, such lithofacies palaeogeography maps are no longer sketchy and qualitative, but quantitative instead Quantification is the most important character of the author's lithofacies palaeogeography maps This makes lithofacies palaeogeography map and lithofacies palaeogeogaphy develop into the quantitative stage This is an important development in palaeogeography

笔者倡导并持续采用单因素分析多因素综合作图法这一定量的岩相古地理学方法论。单因素是能独立地反映某地区、某地质时期、某沉积层段沉积环境某些特征的因素,它的有无或含量的多少均可独立地反映该地区、该层段沉积环境的某些特征,如沉积环境水体的深浅、能量大小、性质等。某沉积层段的厚度、岩石类型、结构组分、矿物成分、化学成分、化石及其生态组合等，均可作为单因素。单因素分析多因素综合作图可分三个步骤：第一，是对各剖面尤其是各基干剖面进行认真的地层学和定量岩石学研究，取得各种第一手的定性和定量资料，尤其是定量资料，了解各剖面各沉积层段的沉积环境特征。第二，在已取得的各剖面的定量资料中，按要求的作图单位，选择出那些能独立地反映其沉积环境特征的因素，即单因素；并把全区各剖面各作图单位的各种单因素的百分含量都统计出来，作出各种相应的单因素图，主要是等值线图。这些单因素图可以从不同的侧面定量地反映该地区该沉积层段的沉积环境。这就是单因素分析。第三，把这些定量的单因素图叠加起来，并结合该地区该沉积层段的其他定量和定性资料，去粗取精，去伪存真，全面分析，综合判断，即可编制出该地区该沉积层段的定量岩相古地理图。这就是多因素综合作图。这一方法论的核心是定量，即以各剖面的定量单因素资料为基础，从各单因素图的分析入手，再通过各单因素图的叠加和综合分析判断，最后作出定量的岩相古地理图。在这种岩相古地理图中，各古地理单元的确定都有确切的定量资料和单因素图为依据。定量是笔者等用单因素分析多因素综合作图法编制出的岩相古地理图的最大特色。这就使岩相古地理图和岩相古地理学发展到了定量的阶段。这在古地理学中是个重大的进展。

文章通过对含矿岩系岩石、矿物、微量元素及沉积特征的阐述,概括了贵州道真县大塘铝土矿的沉积相特征并对铝土矿沉积环境进行了探讨.

摘　要：

豫西郁山铝土矿床是河南省新发现的一大型隐伏铝土矿,属华北地台G层铝土矿.以系统的中-深部钻探工作为基础,根据含铝岩系的岩性组合、沉积构造和地球化学特征,将郁山矿区内上石炭统一段分为2个相和4个微相.提出郁山铝土矿床含铝岩系形成于滨海泻湖潮坪环境,铝土矿主要赋存于豆鲕状(含砂砾屑)铝土矿微相中,为局限潮下带上部环境;认为郁山矿床含铝岩系经历了3期规模不断增大的突发海侵到缓慢海退的沉积环境演化旋回,并形成矿床的3个铝土矿层,最后一次大规模海侵-海退事件形成了区内最连续的铝土矿层(体).通过研究,进一步完善了华北地台本溪组铝土矿成矿理论.

Bauxite in China is mainly palaeoresiduum sedimentary bauxite deposits (98.83% in the total reserve), which is called the karst type abroad. And the lateritic type of bauxite deposits is only 1.17% in the total reserve. In China the genetic mechanism of palaeoresiduum sedimentary bauxite deposits is considered as the colloidal chemical sedimentation by the most mineralogists and it is considered as the sedimentation of meohanical elastics and suspended materials. Based on the research results as followings: 1) The Oxygen Isotope Analysis:the δ~(18)O‰. value(SMOW) of the diaspore, which is the main clay mineral in palaeoresiduum sedimentary bauxite deposits, is about +5-+ 10.9, average +9.2. This value verifies that the diaspore is formed by weathering and the crystalinity index of the clay minerals in the bauxite deposits shows the origin of terrigenous clastic materials as wells 2) No sedimentary traces which are often seen in water sediments, such as bedding, cross bedding, ripple mark and crack, are found in the deposits, and neither are animal fossils; 3) The ores of the palaeoresiduum sedimentary bauxite deposits are all earthy, semiearthy or dense in structure without exception and under microscope their textures are psammitic or gravel-clastic and the shape of the clastic is subround or sub-edge-anglar, indicating the sediments to be transported, and no mechanical differential sedimentation has been found, thus they are quite similar to the earthy or semiearthy clastic bauxite ores near palaeoshores or in the central of sea basins; 4) The striae on the surface of diaspores under scanning electron microscope and the cracks of oolitic grains under microscope indicate the transportation in atmosphere; 5) Pores are well developed in the bauxite ores under scanning electron microscope many miarolitic cavities, in which there are secondary diaspores with good crystalinity as well as boehmites and under microscope can be seen secondary kaolinites filled between psammitic grains and gravel-clastic grains, and the ores become poor in quality in a certain depth below ground water, which indicates that SiO 2 has been leached away and alumina is enriched in the epidiagen-etic stage; the author thinks that the origin of the palaeoresiduum sedimentary deposits in China is "a terrestrial and hydatogenous deposit with superficial enrichment". The sedimentary process of the ores can be divided into three stages as followingS: 1) Alumina-bearing rocks in continent become drift-bed calcium lateritic beds or lateritic beds in bauxite-bearing residuum through weathering; 2) After sea water or lake water covers the eluvial beds, primary bauxite stratum in poor quality is formed during sedimentation; 3) The primary ore bed goes up with the rise of crust and, hence, enters into the superficial stage, upon the action of groundwater or surface water the SiO 2 is leached but alumina enriched, and finally the bauxite deposit with industrial value is formed.

我国铝土矿床按最近作者等（1984,1985）的意见主要的是风化壳沉积型（Ⅰ型）,占我国铝土矿石储量98.83%,其次是红土型（Ⅱ型）,占我国矿石储量1.17%。前者又分三个亚型即Ⅰ 1 修文式——碳酸盐古风化壳沉积亚型,占Ⅰ型矿石储量83.2%,分布在山西、贵州、河南、四川、山东、河北、陕西、辽宁、江西、新疆等省（区）;Ⅰ 2 苹果式——碳酸盐古风化壳沉积——近代卡斯特堆积亚型,占Ⅰ型矿石储量13.04%,分布在广西、云南等省（区）;Ⅰ 3 乐山式——硅酸盐古风化壳沉积型,分布在四川、贵州北部、湖北、湖南等省。红土型（Ⅱ型）分布在福建、广东。是第三纪到第四纪玄武岩在近代气候条件下风化作用形成的三水铝石矿床。其成因已得到我国铝土矿床地质工作者的公认,与国外的意见也一致,本文不再讨论。但是我国对于古风化壳沉积型铝土。

中国铝土矿的成因类型,过去划 分太简单。本文根据实际情况,作了比较详细的划分。首先依大地构造分为地台区与地槽区,然后按主要成矿作用划分八个大类及二个准大类,再根据形成特点(包 括成因、沉积环境或主要矿物特征等)细分为21个类型及9个准类型。其中有几个为新的类型,这个分类结果与世界铝土矿分类有较大不同。

China is one of the most important Carboniferous bauxitebearing countries in the world.One hundred and more large and mediumsized Carboniferous bauxite deposits with the reserve of one billion tones have been found. About 75% of the total deposits occured mainly on the Middle Carboniferous karst basement of North China plateform, subordinately on the lower Carboniferous karst surface in G-uizhou. Only a few of them belong to geosynclinal karst bauxite (merely found in small-sized deposits in Mount Wushibei of Xingjiang ) . Nearly all of the bauxite are diasporite karst ones,with a few small sized bauxite deposits accompanied by boehmite. As a rule, diasporite, as well as dickite accompanied sometimes therein, are not formed under normal temperature and pressure, but derived from other minerals or substances in deuter-diagenesis period. The formation of the deposits is believed to take place near the ancient equator (deduced from theory of plate movement), resulted from severe chemical weathering under moist and hot climate, and from "consecutive formation" suah as short-distance transportation, deposition, diagenesis,deuterogene, hypergene and post-weathering. Very few deposits have undergone contact metamorphism. Differences manifest themselves in various parts and deposits. The material comes mainly from alumi-nasilicate rock and the weathering resideum of limestone. Colloform and debris are, in varying degrees, both the modes of transportation. Abundant good-quality b-auxites are formed mainly in lakes, lagoons and gulf, ore is closely related to t-he desilication desulphate and deferrization during the post-weathering and leaching. But those formed in marshes and rivers are inferior and small in scale. Due to the slight motions of shaking or frequent seismic activities ( including sub-kastification in pay bed after sedimentation in the crust of pene-plateform after deposition of bauxite, the above-mentioned main factors accompanied with the effect of flood and windstorm made the bauxite bed of deposition again or m-ore times eroded by the waves of waterflow and migrated faintly or subsided, even broken down. During this time, "interior fragment" was produced. And then the turbidity current deposit and windstorm deposit of bauxite was formed, (note: Tie author is the first man who put forward the newtheory "the bauxite of windstorm deposit" , but it is only an initial idea and needs a further study ) The bauxite of turbidity current deposit mainly occurs in the deep lake district. There the sorting and the thickness of bed is uneven ( several centermeters to meters ) . The sequence of grain is thick on bottom and fine upper, showwing a decrease in energy. The bauxite of windstorm deposit occurs mainly in the shallow lake district. There the bauxite is stored well. The thickness of flag bed is uniform ( from several centimeters to tens of centimeters ), with a sequence of fine grain on bottom and thick upper, howing a increase in energy. The author believes that both diosporite and dickite which sometimes contains constitutional water in Carboniferous bauxite in China is frequently formed by solidus reaction and solid transportation during diagenesis and deuterogene. The composition of O isotope in it is unchanged basically. It means a "preservation"; conversely, that formed by solution, the primary compositions of O isotope are exchanged ( see Fig.1) . Detailly, the diosporite is formed by alumina-gel in aocient crust of weathering( suspended transportation ) and colloidal solution at the initial stage of diagenesis of reductive environment ( including transformed by gibbsite). The phenomena of constitutional water ( means colloidal water from ancient crust of weathering), vegetating recrystallizing and sequence belong to the solid reaction.The exchange in diagenesis and deutero-water of 0 isotope is uot caused, so the O isotope possess preservation of "weathering crust" 5 and"laterite property" 7. It is derived from kaolinite deposited from ancient weathering crust and gel since the deuterogene present solid

世界石炭纪铝土矿主要产于中国,其形成条件因当时处于湿热的热带地区,构造长期稳定,准平原化排水条件好,强烈的化学及生物风化后产物经水流短程搬运,成胶体及碎屑不同程度兼有的混合沉积;往往经多次的震荡运动或地震活动成内碎屑浊流沉积;还遭受成岩、后生、表生及后期风化作用等的改造,而富集成矿。其中硬水铝石及地开石一般不形成于氧化的风化壳,主要是还原的成岩后生作用转变的,固相转化的氧同位素组成仍可具有“红土性质”或“风化壳性质”的保存性。

沉积铝土矿岩石的结构构造对于 矿床成因有着十分重要的关系。但过去研究很不够,首先在定义上很混乱;把结构当构造,或把构造当结构也是常有的。再者结构构造在铝土矿床空问分布含量上, 以及形成作用与形成阶段均需仔细研究,从而得出比较确切的成因认识。作者通过研究,认为我国沉积型铝土岩石的结构构造是各种各样的,其形成作用和形成阶段 也是多种多期的,而不能一刀切。其与红土型铝土矿也不同。也不是单纯的“胶体化学沉积”或单纯的“机械沉积”。而是多因素、多阶段、不同程度的成矿。

Sedimentary bauxite ores in China are often with pisolito-oolitic structure. Observations under microscope and scanning electron microscope, microprobe and isotopic analysis show their complexity, so is their genesis. Synsedimentary pisolites and oolites are dominant, then the lateritic ones and a few of them are dia-epigenetic. Quality of the sedimentary bauxite ore tends to be related to morphology of pisolites and oolites as well as their distribution.

我国沉积铝土矿石常具豆鲕构造,通过显微镜与扫描电镜观察,并进行电子探针及同位素等分析后,认为豆鲕粒复杂,成因也不单纯。主要形成于同生沉积阶段,其次为红土风化阶段,少数为成岩后生阶段所形成。还发现豆鲕的形态和分布特征与矿石质量好坏有关。

The Permian in the DianQianGui Basin and its adjacent areas can be divided into three series,the Chuanshanian, the Yangxinian and the Lepingian SeriesTwo obvious unconformity surfaces, one resulting from the main episode of the QianGui structural movement at the turn from Chuanshanian Epoch to Yangxinian Epoch, and another resulting from the main episode of Dongwu structural movement at theturn from Yangxinian Epoch to Lepingian Epoch, not only become the evidentsequence boundaries of type I but also represent the important changing surfaces of palaeogeographical patterns and the characters of the sedimentary basinin the study areaThe Permian System in the DianQianＧui Basin and its adjacent areas is marked by the clear sedimentary facies differentiationThe development of coalbearing strata on the attached platform as well as the formation ofsponge reefs and grain banks in the margin of attached platform and on the isolated platforms led to a particular palaeogeographical pattern thatis characterized by “platformbasinhilltrough”.Concomitantwith the firstepisode of the Dongwu structural movement,a strong volcanic eruption occurredin the northwestern part of the study area, which led to the formation of the widely distributed “Emeishan Basalt”.At the same time,the “QinzhouFangcheng relict trough" was closedThese important events resulted in the great changes of the palaeogeographical patternsThe typical drowning event of the carbonate platforms at the turn from the Permian to the Triassic formed a typical drowned unconformityAccording to the regularities represented by the evolution succession of sediments as well as the distribution patterns of sedimentary facies, the Permian in the study area could be divided into several thirdorder sequencesThe top part of the Carboniferous and the Chuanshanian Series of the Permian form one sequence(SQ 19 ),the Yangxinian Series includes four sequences  from SQ 20 to SQ 23 , and the Lepingian Series could be divided into two sequences including SQ 24 and SQ 25 Ultimately,the complex but regular facieschanges in time and in space can be clearly illustrated by the palaeogeographical maps as well as the panel diagrams of sequence stratigraphic frameworksFirst, the main temporal facieschanging surfaces marked by the abrupt changes of sedimentary facies and the stratigraphic hiatus form the sequence boundariesDue to the different duration of stratigraphic hiatus at different locations,the diachrononism sequence boundaries of “punctuated surfaces" are formedSecond, the spatial changes of sedimentary environment as well as the migration of sedimentary facies during the temporal changing process always result in the spatial changing surfaces of sedimentary facies marking the obliqueness with chronostratigraphic surfaces and in the end the diachronism of “facieschanging surfaces" is formedThird, various faciessuccession fabric of sequences is formed in different depositional periods, and is regularly changed in space, which means different palaeogeographical backgroundsTherefore, it could be concluded that the regularity represented by “the evolutionary succession of sediments and the distributional pattern of sedimentary facies" is the key factor on the study of sequence stratigraphyOn the basis of biostratigraphic materials, this kind of regularity could be used as an indicator in the division and correlation of strata

滇黔桂盆地及邻区的二叠系包括船山统、阳新统和乐平统。船山统与阳新统之交的黔桂运动主幕不整合面、阳新统和乐平统之交的东吴运动主幕不整合面的不整合特征明显，同时因其代表了研究区沉积盆地性质发生较大变化的界面而成为较为典型的I型层序界面。滇黔桂盆地及邻区的二叠系以其明显的沉积相分异而引人注目：在连陆台地上发育含煤地层，而在连陆台地边缘及孤立台地上发育海绵生物礁，形成一个典型的“台-盆-丘-槽”的古地理格局。伴随着强烈的东吴运动第一幕，研究区西北部发生强烈的火山活动，形成分布范围较广的峨嵋山玄武岩；东南部的“钦防残留海槽”关闭，使研究区的古地理格局发生了较大变化。二叠系与三叠系之交发生的较为典型的台地淹没事件形成了一个较为典型的淹没不整合面。根据沉积物的时间演化序列和沉积相的空间展布形式所指示的规律，研究区的二叠系可以划分为以下三级层序：船山统与下伏石炭系顶部的地层构成一个三级层序(SQ 19 )，阳新统包含四个三级层序(SQ 20 到SQ 23 )，乐平统包括两个三级层序(SQ 24 和SQ 25 )。在层序地层框架内，系列古地理图和系列层序地层格架栅状图较为系统地反映了研究区二叠纪复杂而有序的时间和空间相变特征。主要的时间相变面即形成层序界面，具有明显的“跳相”和地层间断现象，由于在不同地点间断的时限不一致而造成“间断面穿时”；沉积环境的空间变化，以及伴随着时间变化中的相带迁移所造成的空间相变，其相应的相变面总是斜交时间面而造成“相变面穿时”；不同沉积阶段的层序具有不同的相序组构，并在空间上形成有序的变化，从而代表了不同的古地理背景。因此，层序地层研究的核心内容是“沉积物的时间演变序列和沉积相的空间展布形式所代表的规律性”，结合生物地层特征，这种规律性本身也可以作为地层划分和对比的标志。

滇黔桂盆地及邻区的二叠系乐平 统,包括吴家坪阶和长兴阶;其沉积相类型多样,沉积相分异明显,为层序地层研究提供了得天独厚的有利条件.大致相当于吴家坪阶的地层构成一个三级层序,而 大致相当于长兴阶的地层组成另一个三级层序.在连陆台地上,吴家坪阶为一套含煤碎屑岩系地层,而且在孤立台地上的灰岩层中也发育煤层,连陆台地边缘和孤立 台地的迎风浪部分主要为颗粒滩相灰岩;长兴阶,连陆台地上主要由开阔海台地相灰岩组成,在孤立台地上以及连陆台地边缘为一套海绵生物礁灰岩.在台盆中,乐 平统为一套盆地相泥页岩夹硅质岩;在钦州至防城一带,覆盖在深水盆地相地层之上的是巨厚的乐平统磨拉石粗碎屑岩地层.这些特征表明了研究区域乐平统复

In this study the authors have discovered many characteristic textures and structures of bauxite as shown in Fig. 1 and P1. I, 1-6. Based on these criteria a sedimen-tologic classification of bauxite (Table 1) is proposed as follows:I. Primary bauxite:1. Autochthonous bauxite: Autocoated bauxite and algal-bound bauxite;2. Allobauxite: granular bauxite and muddy bauxite. II. Secondary bauxite:1. Shelly bauxite;2. Honeycomby bauxite.The following is the main bauxite microfacies (MF):’AWCI’ MF: coarse-grained bauxite deposits transported by current-wave generation (Fig.2);’AWCC’ MF: coarse coated-grained bauxite transported by current-wave generation (Fig.1-1);’AUCC’ MF: Auto-weathered coated-grained bauxite former in eluvial-crust environment;’RTC’ MF: resedimentary coarse-grained bauxite deposits transported by storm-turbidity flow.Four types of sedimentary sequence have been recognized by the authors: 1. current-channel sequence (Fig 3); 2. turbidity sequence (Fig. 4); 3. tidal flat sequence (Fig. 5); 4. coastal-submarine sequence (Fig. 6). Main ore deposits of bauxite are in the 1, 2 and 3 sequences.To sum up, the authors suggest a schematic sedimentological model for the formation of the Carboniferous bauxite of North China (Fig. 7), in which the process of storm-tubidity flow has played an important role in the aceumulation of bauxite deposits.The evidence of storm activity in the sedimentary sequence is as follows: 1) The presence of hummocky stratification in limestones, 2) The presence of swaley cross stratification in sandstones, 3) the characteristic turbidity pattern normal probability cumulative curve in RT-bauxite, and 4) the re-sedimentary textures and structures found in bauxite (Figs. 1 B, C. G. H. I and J).

作者在铝土矿研究中发现了许多新的显微成因结构类型。依据这些标志提出了一个铝土岩的沉积学成因分类。并划分了主要微环境的铝土岩微相类型。作者鉴定出四种铝土质沉积序列。综合上述研究,作者建立了华北石炭纪钼土矿沉积模式。在这一模式中风暴浊流对铝土矿形成富集起着特殊重要的作用。

Late Permian Xuanwei Formation(corresponding to Longtan and Changxing Formations) in the eastern Yunnan and western Guizhou consists of coal-bearing clastic sequences. Some thick bedded basalt conglomerates were developed at the bottom of the sequence ( Lower Member of Xuanwei Formation).In this paper, the distribution and the depositional environments of the conglomerates are investigated and their relations to the coal-accumulation are discussed. The cotlglomerates are distributed to the east of Xiaojiang Fault (S-N trend ) along the east side of the Kangdian paleocontinent and they are displayed in four E-W trend belts. Our researches are focused on the Xundian-Fuyuan-Panxian conglomerate belt. Gravels of conglomerates are 5cm to 25cm in size, well rounded, middle to well sorted and gravel supported. The contents of gravels are mainly basalt fragments and occasionally siliceous rocks, tufaceous rocks and agates. The matrix consists of fine sands, plant debris and siliceous, calcareous and glauconitic cements.Sometimes marine algae fossils can be found in martix. These conglomerates are believed to be the deposits of braided delta depositional system. The main facies are pebbly braided channel conglmerates with erosional bottom and unidirectional imbricated structures. sandy braided channel sandstones with trough cross stratification and many erosional bases，pebbly mouth bar conglomerates with evident bidirectional grain orientation，and sandy mouth bar sandstones and siltstones with upward coarsening sequence and many tidal flat muddy pebble and tidal lamination.During the activation of marginal fault(Xiao jiang Fault)，the progradation of each braided delta will produce an irregular upward-coarsening delta front sequence. But in some areas, the basal conglomerate beds directly cover on the paleoweathering surface on the top of Lower Permian. These basal conglomerates are probably the results of the rapid progradation of braided channel and the tidal winnowing during the initial strong activity stage of marginal fault. The coal accumulation were controlled by the braided-delta. During progradation of delta，the coal-accumulation mainly occured at the inter-channel areas on the delta plain. During retrogradation of braided delta，the coal-accumulation occured on the gradully abandoned delta lobes. As a result,at the lower part of the Lower Member of Xuanwei Formation，which was formed during the progradation of delta, the coal seams are restrictly distributed，thin and discontinuous. At the upper part, which was formed during the retrogradation of delta, the coal seams are generally thick and continuously distributed. In the inter-delta lobe areas, the coal seams are well developed both at the lower part and upper part. It can be concluded that the coa-accumulation is favored in the inter-delta areas and on the declined delta lobe.

滇东黔西上二叠统底部发育着一套玄武岩质砾岩，本文针对云南富源和贵州盘县一带的底砾岩进行综合研究，认为这套砾岩为辫状河三角洲沉积，并进一步识别出砾质辫状河道、砂质辫状河道、砾质河口坝、砂质河口坝等沉积类型。文中还对该辫状河三角洲的沉积序列、发育背景以及与聚煤作用关系等问题做了一定分析，认为三角洲朵体之间地区以及在衰退的三角洲朵体之上成煤较好。

The study areas include Guizhou, southern Sichuan, and eastern Yunnan, where abundant coal resources are preserved in Late Permian strata. The Late Permian key fauna and flora and their combinations are studied and a scheme of stratigraphic multi-subdivision for Late Permian succession are established. Typical Changxingian ammonoids such as Sinocel ites sichuanensis and Pseudotirolites qianjiangensis have been found in C 12 coal seam of the Huoshaopu coal mine, Panxian County, western Guizhou, and a Changxingian Brachiopod fauna have been found in B4 marker limestone of the Yanbeihou section, Zhijin County, western Guizhou. This makes it possible to subcorrelate the Late Permian invast areas of southern China. For lithostratigraphic purposes, the upper Permian is subdivided into the Longtan Formation (Wuchiaping Formation, Middle and lower Members of Xuanwei Formation) and the Changxing Formation (Wangjiazai Formation, Dalong Formation, and upper Member of Xuanwei Formation). The Longtan Formation is subdivided into the lower Member and the upper Member. Synthetic studies suggest that the Late Permian coal-bearing sequences in study areas were mainly formed in five depositional systems, including braided river and braid delta system, alluvial plain fluvial system, deltatidal flat system, Lagoon-tidal flat system, and carbonate Platform System. The delta-tidal flat system is believed to be the most important system for the coal accumulation in western Guizhou. This system can be further divided into the fluvial-dominated upper delta plain, fluvial and tide influenced transitional delta plain, and tide-dominated lower delta plain and tidal plain environments. The overall paleogeographical units of the Late Permian in the study areas include non-marine alluvial plain dominated by fluvial channel, alluvial fan in eastern Yunnan, transitional paralic plain dominated by deltatidal flat system and lagoon-tidal flat system in westerm Guizhou and southern Sichuan, marine carbonate platform in eastern and southern Guizhou, eastern part of southern Sichuan, and southern part of eastern Yunnan, and deep water fault basin in the vicinity of Ziyun of southern Guizhou. Lithofacies paleogeographical maps of Early Longtanian stage, late Longtanian stage and Changxingian stage have been drawn based on analysis of various contour maps such as clastic and carbonate rocks ratio, thickness of sandstones, percentage of sandstones, thickness of coal seams, and thickness of strata.

位于上扬子板块的贵州、滇东、川南地区发育着丰富的晚二叠世煤炭资源，本文对该区晚二叠世地层、沉积环境和古地理进行系统研究，提出该区岩石地层划分对比方案，在沉积环境方面，提出本区三大相区、五种沉积体系和多种沉积相类型。分龙潭早期、龙潭晚期和长兴期。论述了研究区晚二叠世古地理演化。并对聚煤作用控制因素进行分析，认为煤层发育层位受幕式聚煤作用控制，煤层厚度则与下伏沉积物的沉积环境有关，聚煤有利部位为位于海陆交互相区的黔西地区，有利聚煤的沉积体系为三角洲-潮坪体系。