Homalophyllum属的个体演化及其骨骼微细构造的电镜研究

本文通过对采自内蒙古下泥盆统珠斯楞组的Homalophyllum属的系列切片及电镜研究表明:（1）其个体发育早期,主隔壁细长,无中轴,至晚期,上隔壁变短,一级隔壁在轴部膨大形成明显的中轴。（2）骨胳构造以纤状骨骼为主,呈扇状排列,规则完整的晶榍构成隔壁构造。其基本组成单元为向上逐渐展宽的桨状晶条。本属的层状骨骼为方解石晶片,只见于外壁部分。笔者对Homalophyllum colmniferum（新种）也作了描述。     

四射珊瑚AuloPhyllum fungites骨骼微细构造的电镜研究

本文对Aulophyllum fungires （Fleming）,1828的骨骼微细构造进行了扫描电镜研究.结果表明,其骨骼纵列构造和横列构造全由纤状骨骼方解石晶针构成.晶针大小可分两级:大者在隔壁和横板中,大小近相等,其平均长度为32μm,平均直径为4μm;小者在鳞板,内斜板和柱隔壁中,其平均长度为10μm,平均直径2μm.晶针只在隔壁中沿轴部组成一排晶（?）,其平均直径为30—60μm,晶（?）两侧晶针组成晶束几近垂直,并间歇生长.在纵切面上,横板与隔壁相接处,间歇生长线是连续的,说明两者同步增长和形成过程相同.     

泡沫珊瑚目的骨骼构造和系统分类

本文以骨骼微细构造为重要根据,系统地论述泡沫珊瑚目的骨骼构造及分类演化。通过对泡沫珊瑚 目10余属骨骼微细构造的电镜研究,建立了两种不同的骨骼类型:层状骨骼和纤状骨骼。前者基本单元 为方解石晶片,直径15一35林爪,厚度约1.5一2.5卜m。后者则是原始的晶粒(直径2一3卜m)和不规 则短轴晶柱(直径2一3卜m,长度5一10林m)。这些单元以不同的方式组成四种隔壁刺或晶桶类型: 1.全晶椒,几乎完全由晶片环绕构成。2.单杆晶彬,由轴部的晶粒和短轴晶柱以及包绕的层状晶片 组成。3.复式杆晶桶,由单杆晶据丛状集结,其间由层状骨骼连结而成.4.单晶梢,由平行排列的 短轴晶柱或晶针构成.图版及其说明中所歹IJProtoeyst落p而yll。优,R几abdoevel“s,Gyalophvl- Ioides,和Tr夕Plas阴al)是这四种晶掘的代表属。 本文承认了泡沫珊瑚目50属,分属于s科:Primitophyllidae,Pala。oey。lidae,Tryvlasma- tidae,CystiPhyllidae,Mueophyllidae,Holmophyllidae,Goniophyllidae,Ketophyllidae, 对各科提出了简要定义和讨论。 根据各科属的时空分布,概述了泡沫珊瑚目的演化关系。认为最早出现的FrimitoPhvllidae科和 MueohPyllidae科可能源于不同的祖先。Pal3eoevelidae科和Tryplasmatidae科可能是从Primi- tophyllidae科分出的两支.Cystiphyllidae科是由PrimitohPyllidae科分出的另一支,它迅速辐 射形成Goniophvllidae,Holmophyllidae,Ketophyllidae等三科,构成志留纪泡沫珊瑚的主 体。     

四射珊瑚属Lophocarinophyllum的骨骼构造兼论Lophophyllidiidae科

Lophocarinophyllum属以中轴粗大,隔壁两侧发育平列脊板,横列构造发育微弱为主要特征。骨骼微细构造属纤状及层纤状类型。隔壁和脊板可由单晶榍组成,也可由轴带不规则细小晶榍与两侧带近平行的晶针和晶束组成。由于Lophocarinophyllum acanthiseptum发育微弱横板,将Lophotabularia列为Lophocarinophyllum的同义名。Lophocarinophyllum共包含8个种,其中1个新种(L. stereoseptum sp.nov.). Lophophyllidiidae科有8个属: Lophophyllidium、Sugiyamaella、Lophocarinophyllum、Stereostylus、Neostereostylus、Timorphyllum、Lophamplexus、Paralophophyllidium.     

晚石炭世及早二叠世部分常见复体四射珊瑚骨骼微细构造及其分类意义

本文通过对晚石炭世及早二叠世几种常见复体四射珊瑚的骨骼,尤其是隔壁的电镜研究、划分出了4种重要的隔壁微细构造类型,并指出了这些微细构造类型的地层分布规律及其在分类中的意义。     

异珊瑚隔壁的排布系列

异珊瑚原始隔壁数目、后生隔壁的增生部位和方式以及隔壁的排布系列的研究，是探讨异珊瑚的起源、演化和分类的基本前提。通过对3隔壁的Triphyllia和4隔壁的Quadratphyllia二属的研究，结合生物体对称的原则，提出异珊瑚原始隔壁为2条，并认为异珊瑚的后生隔壁发育在原始隔壁所分隔的左右两侧部体腔内缘部位，长隔壁呈树枝状拓布或者末端达中心向某一方面扭曲连接形成轴管构造。依据后生隔壁在体腔内的繁生能力、增殖数量、发生部位、排布方式、分化程度、隔壁始端在外壁中的埋植类型和末端在中心部位的连接类型等方面的不同，异珊瑚隔壁增生大致可划分为7个布系列。     

中国的异珊瑚

从６０年代开始，我国学者陆续发表了异珊瑚的研究成果，建立１３个属，描述１６０余种，所发现属种数量已大大超过国外学者所描述范围，并且在异珊瑚分类，骨骼微细构造及隔壁演变规律研究等方面都取得长足的进展，特别是发现具３个隔壁的异珊瑚，对异珊瑚的隔壁发育方式及各属间隔壁变异关系有了清楚地揭示，在分类方面可将异珊瑚分为具内沟和不具内沟的两个系列，异珊瑚在我国产出时代为泥盆纪早期至石炭纪晚期，我国的异珊瑚绝大     

甘肃迭部早石炭世异珊瑚的发现及Radiciphyllia的微细构造

本文描述早石炭世异珊瑚类５属６种,包括ＨｅｘａｐｈｙｌｌｉａｆｌｏｒｉｆｏｒｍｉｓＷａｎｇｅｔＹｅ,Ｈｅｔｅｒｏｐｈｙｌｌｉａｔｅｗｏｅｎｓｉｓ（ｓｐ．ｎｏｖ．）,Ｈｅｔｅｒｏｐｈｙｌｌｏｉｄｅｓｃｆ．ｙｕｎｎａｎｅｎｓｉｓ（Ｄｕａｎ）,Ｆｏｓｓｏｐｈｙｌｌｉａｓｐ,,Ｒａｄｉｃｉｐｈｙｌｌｉａｇｉｇａｎｔｅａ（ｓｐ．ｎｏｖ．）．以上标本产自甘肃法部益哇沟、东支沟部面下石炭统大塘价上部,此外Ｒａｄｉｃｉｐｈｙｌｌｉａｓｐ．产自益哇沟下石炭统德坞阶．笔者对Ｒａｄｉｃｉｐｈｙｌｌｉａｇｉｇａｎｔｅａ个体的骨骼微细构造进行扫描电镜研究,其隔壁、横板、外壁均为纤状组织,并由短轴晶柱及晶粒组成．本文还简要讨论Ｒａｄｉｃｉｐｈｙｌｌｉａ的分类位置及其亲缘演化关系．     

中国的异珊瑚

从６０年代开始，我国学者陆续发表了异珊瑚的研究成果，建立１３个属，描述１６０余种。所发现属种数量已大大超过国外学者所描述范围，并且在异珊瑚分类、骨骼微细构造及隔壁演变规律研究等方面都取得长足的进展。特别是发现具３个隔壁的异珊瑚，对异珊瑚的隔壁发育方式及各属间隔壁变异关系有了较清楚地揭示。在分类方面可将异珊瑚划分为具内沟和不具内沟的两个系列。异珊瑚在我国产出时代为泥盆纪早期至石炭纪晚期。我国的异珊瑚绝大多数产于早石炭世大塘期的海相地层内，常与Ｙｕａｎｏｐｈｙｌｕｍ带的皱纹珊瑚共生，是划分早石炭世地层的重要化石     

华北下二叠统太原组Zoophycos潜穴中碳酸盐岩微形体的特征及其意义

华北地区下二叠统太原组碳酸盐岩中的Zoophycos遗迹化石十分丰富,根据其潜穴充填物颜色的不同,可将太原组Zoophycos分为四种类型,即具黑色、灰色、灰白色、红色充填物的Zoophycos。本文选取河南焦作和山西附城太原组剖面中具有代表性的Zoophycos样品,利用扫描电子显微镜和能谱仪对其潜穴中的充填物进行了超微特征观察及元素组成测定,发现了大量成因与微生物相关的碳酸盐岩微形体（单体矿物和集合体）,识别出球状（表面光滑的球状体、表面具有不定形细粒结构的球状体、表面呈刺状细粒结构的球状体和球状集合体）、杆状（刺杆状分枝形网状体、刺杆状单体、螺旋杆状单体、双列杆状体、光滑直线形杆状单体、末端膨大的光滑杆状体）、簇状、网状、瓶状和似脑球状等6种形态类型,其中多数显示出不同的微生物结构。这一发现表明,Zoophycos遗迹化石并非简单的觅食迹或食物储藏所,其造迹生物与微生物很可能存在互利共生关系。此次研究有助于探索地质微生物作用对地球化学过程的影响,并为精细分析该研究区太原组碳酸盐岩的形成过程及其沉积演化提供了微观资料。     

海南岛南部一地全新世生物屑灰岩的成岩作用

引言研究标本由我所碳酸岩组采自海南岛南部的一个地点。在那里,沿岸覆于原生礁之上有一套由生物骨屑(主要是珊瑚)砂、砾所组成的、已被碳酸盐胶结的岩层,其厚约3米左右(图1)。此岩层一般称为“次生礁”。它是由当时原生礁盘上的生物被海浪击碎并冲带到礁盘上沉积下来的,这里属连岛砂堤沉积,它现已完全暴露地表。次生礁在它抬升过程中,下部被海蚀形成海蚀龛。     

异珊瑚隔壁的变异及其分类

自发现具有３个隔壁的异珊瑚新类型之后，对异珊瑚各属之间的隔壁变异关系有了清楚的揭示。按照后生隔壁发育的方式，可分为具内沟的异珊瑚，即由３个隔壁的Ｔｒｉｐｈｙｌｌｉａ，５个隔壁的Ｐｅｎｔａｐｈｙｌｌｉａ，直至多隔壁的Ｆｏｓｓａｐｈｙｌｌｉａ系列和不具内沟的异珊瑚系列，即由４个隔壁的Ｑｕａｄｒａｔｉｐｈｙｌｌｉａ，６个隔壁的Ｈｅｘａｐｈｙｌｌｉｕ，直至多隔壁的Ｈｅｔｅｒｏｐｈｙｌｌｉａ。此外，还可出现具有轴管结构的Ｃｒｅｐｉｄｏｐｈｙｌｌｉｄａｅ及具有特殊外壁结构的Ｌｏｎｇｌｉｎｏｐｈｙｌｌｉｉｄａｅ。对已发现的异珊瑚１９个属作了系统的分类，并将异珊瑚置于珊瑚纲内的一个亚纲，同皱纹珊瑚亚纲相并列的分类单位。     

Carbonate cementation of some Pleistocene temperate marine sediments

Carbonate cementation of some carbonate and quartz sands in three raised beaches of temperate origins was investigated. The carbonate of the cements was found to have been derived from the dissolution of skeletal debris. The sandstones, so produced, now possess only low-magnesium calcite, but the original sediments, like adjacent modern beach and blown sands, probably contained low-magnesium calcite, aragonite and some high-magnesium calcite, all of skeletal origin. In meteoric water the dissolution has occurred of all carbonate within minute, tubulelike, volumes of sand. Concurrent deposition in adjacent volumes of sand of low-magnesium calcite formed cements that are irregularly nodular or uneven on a small scale. Aragonite within the minute nodules has been replaced paramorphically by low-magnesium calcite. Additional local carbonate cements were formed at later dates, around and within solution pipes.     

Relationships between lithology and diagenesis in a limeston—marl facies transition: an electron microprobe study

A 3 km long lateral facies transition from Oligo-Miocene skeletal grainstones into packstones and mudstones displays systematic variation in carbonate skeletal fragment alteration and secondary carbonate mineral composition. Within the skeletal grainstone end-member all aragonitic grains have dissolved, all Mg-calcite skeletal fragments have altered to calcite, and calcite has been precipitated as both void-filling spar and as syntaxial overgrowths on echinoid fragments. Within the transitional grainstone-packstone lithologies some skeletal fragments show preservation of their original mineralogy, while calcite, ferroan calcite spar and dolomite have precipitated in void spaces. Within the packstone-mudstone end-member of the transition, aragonitic grains have been preserved and Mg-calcite skeletal fragments have retained most of their magnesium. Thin, originally porous grainstone layers within the pack-stone-mudstones contain sideroplesite and ferroan calcite spar in void spaces, and iron has been incorporated in skeletal fragments which were originally Mg-calcite. In these grains iron has been incorporated at the expense of magnesium until the grains approach the composition of the surrounding ferroan calcite cement. The lateral variation in diagenetic alteration across this facies transition is a function of differing groundwater movement and composition, controlled ultimately by the composition, porosity and permeability of the host lithologies.     

Calcite from the Quaternary spring waters at Tylicz, Krynica, Polish Carpathians

At Tylicz, near Krynica Spa (Polish Carpathians), spelean deposits fill fissures and caverns in Eocene flysch rocks. They occur as: (1) clastic cave sediments transformed into hard crusts due to cementation by finely crystalline low-Mg calcite, (2) drusy calcite that covers crust surfaces and fills voids in the crust and (3) colloform calcite. Two varieties of drusy calcite are distinguished: acicular and columnar. The acicular calcite is built up of crystallites forming spherulitic fans or cones. In places it is syntaxially covered with colloform calcite. The drusy calcite is low-Mg ferroan calcite with non-ferroan subzones, whereas the colloform calcite is a low-Mg non-ferroan variety. The columnar calcite crystals form fan-like bundles. Cross-sections cut perpendicular to the c-axes of columnar crystals are equilateral triangular in shape, although some have slightly curved edges. The columnar crystals have steep rhombic terminations and most have curved triangular faces, i.e. gothic-arch calcite. Saddle crystals have also been observed. The columnar crystals are composed of radially orientated crystallites whose long dimension is parallel to the c-axis. The curved crystal faces of such polycrystals are interpreted as a result of differential growth rates of the crystallites. The spelean calcites precipitated from CO₂-saturated water. The high rate of CaCO₃ precipitation is thought to be responsible for the formation of radial structures. Finely crystalline calcite formed within pore spaces of clastic sediments close to the water-air interface, drusy calcite crystallized beneath the water-air interface, and colloform calcite precipitated from thin films of water.     

Compositional diversity of soluble mineralizing matrices in some recent coral skeletons compared to fine-scale growth structures of fibres: discussion of consequences for biomineralization and diagenesis

 In contrast to the purely crystalline model of the coral fibre, a transversal zonation is made visible within fibres by specific preparations (enzymatic or light acidic etchings). This growth zonation that corresponds to the successive positions of the secretory ectoderm during septal development shows that crystallization of coral fibre is controlled not only by an external organic coating of fibres, but also includes intra-fibrous organic components. This results in a micron-scaled internal structure of fibres, with a noticeable diversity depending on species. In parallel, soluble matrices also exhibit significant differences, although the global high content in acidic amino acids is always observed. Gathering these two sets of data allows the current ideas concerning structures and growth modalities of coral septa to be discussed. Basically, the respective role of centres of calcification and fibres during septal development appears clearly different from the current ideas, resulting in significant change in interpretation of coral structures, with concerns in both skeleton formation and understanding of diagenetic processes. Received: 2 November 1998 / Accepted: 10 May 1999     

Origin of subaerial Holocene calcareous crusts: role of algae, fungi and sparmicritisation

The Pleistocene Miami Limestone that crops out on the lower Florida Keys is overlain by thin (16 cm or less), discontinuous, Holocene calcareous crusts (caliche) that are usually laminated, composed dominantly of calcite micrite and may or may not incorporate part of the underlying limestone. Both allochems and sparry calcite cement in the former unit contain endolithic algae and fungi, borings and unicellular algae. Biogenic structures identical to those in the Miami Limestone also occur in the calcareous crusts but are somewhat less abundant in the latter unit versus the former unit. The calcareous crusts were formed in the vadose diagenetic environment. Some of the CaCO₃ necessary for the micrite that comprises the bulk of the crusts was probably derived from solution of carbonate from a soil cover and some from wind blown salt spray. Most of the micrite, however, was formed by replacement of the uppermost portions of the Miami Limestone. Replacement involved micritisation of allochems and a previously unreported process, sparmicritisation, the degrading recrystallization of sparry calcite to micrite. Minor sparmicritisation was caused by micrite calcification of endolithic fungi or algae within sparry calcite cement or by micrite precipitation in empty borings within such cement. Most sparmicritisation took place by dissolution of sparry calcite and concomitant precipitation of micrite in the space occupied previously by the dissolved spar. Such sparmicritisation is interpreted to be caused by chemical reactions involving the crystals, pore water which is moving slowly but steadily and organic compounds released during bacterial decomposition of fungi, algae or both. It is recognized that sparmicritisation occurs in the marine diagenetic environment and is not, therefore, necessarily indicative of vadose diagenesis. Incomplete sparmicritisation is responsible for some of the clotted textures typically found within calcareous crusts and may explain such textures in many other carbonate rock types. A combination of sparmicritisation and micritisation has probably greatly influenced the porosity of many reefs and, in some cases, led to the formation of ‘micritic reefs’.