地质瑰宝--叠层石

叠层石是一种微生物岩，在天津市蓟县中上元古界地层剖面中分布之广泛、数量之丰富、种类之多样是世界上其他地区所少见的，因此叠层石的大量发育也是元古界地层的显著特点。叠层石是以兰藻为主的微生物通过生长和代谢活动而吸收沉淀矿物质或捕获矿物颗粒，自一个点或一个表面单向增生，构成具有纹层的层状体所形成的生物沉积构造。它通常由一层碎屑层一层有机层交替叠置而成。     

深海锰续集的分类及两类锰结核的特征

分析了国内外各种深海锰结核分类中存在的问题,提出了新的分类方案,即将前人分类中的次要分类依据（内部构造和表面结构）提高为分类的第一标志,将前人分类中的主要标志（外形和大小）作为第二标志,新分类所划分的表面光滑和瘤状－粗糙深海锰结核正好与微小叠层石和奇异叠层石两个族相对应,而且还进一步与中华微放线菌和太平洋螺球孢菌责任中超微生物化石相对应,两类锰结核在矿物成分、化学成分、叠层石种类等方面的区别十分明显。     

深海锰结核的分类及两类锰结核的特征

分析了国内外各种深海锰结核分类中存在的问题,提出了新的分类方案,即将前人分类中的次要分类依据(内部构造和表面结构)提高为分类的第一标志,将前人分类中的主要标志(外形和大小)作为第二标志.新分类所划分的表面光滑的和瘤状-粗糙深海锰结核正好与微小叠层石和奇异叠层石两个族相对应,而且还进一步与中华微放线菌和太平洋螺球孢菌两种超微生物化石相对应.两类锰结核在矿物成分、化学成分、叠层石种类等各方面的区别十分明显.     

淮南地区新元古代刘老碑组叠层石消失原因初探

安徽淮南地区新元古代刘老碑组主要由页岩和中薄层泥质、粉砂质灰岩组成。在该组上部中薄层砂质灰岩中产有该地区新元古代最古老的叠层石Baicalia和?Linella。大量的臼齿碳酸盐脉体穿插在该组叠层石的基本层中的现象较为独特,该组上部发育的滑塌构造和臼齿碳酸盐岩脉体的特征表明该沉积时期发生过强烈的地震活动;此外,在叠层石礁体周围还有大量的风暴沉积产出。这些现象表明,该组叠层石发育于风暴活动和地震活动交织的环境之中,地震活动是导致该组叠层石消失的主要原因。     

甘肃永昌─独青山地电断面及其地质上的新发现

甘肃永昌─独青山大地电磁测深（ＭＴ）断面可分为４个岩性电性层和两组“构造电性层”，铲状断裂发育，无超壳深断裂。具深、浅双层推覆滑脱构造。金昌硫化铜镍矿床的合矿超基性岩体与深部通道的联系已被错断，是无根的，是推覆滑脱构造由南而北、由深而浅拖带上来的。     

三组元复合材料的有效电导率研究

研究带有壳层的金属球颗粒杂质与基质无规混合的有效电导率,对于带有壳层的同心球可以等效成一个实心球杂质与同一基质无规混合,其实心球的半径等于原壳层的半径,利用倒易定理（ＲＴ）,其结果与有效介质近似（ＥＭＡ）进行比较发现两者基本一致。     

燕山西段前寒武系雾迷山组叠层石的环境意义

叠层石广泛见于燕山西段前寒武系雾迷山组,文中将其分为六种类型:核形石、凝块石、层状叠层石、波状叠层石、锥状叠层石和柱状叠层石。叠层石形态的变化由前向后代表由低能向高能的环境转变,其中以层状叠层石在雾迷山组最为丰富。研究表明,在当时无捕食动物与钻孔动物存在的情况下,大多数叠层石发育于潮下带环境。层状和波状叠层石主要出现在潮下高能带的下部,少量见于受保护的潮间环境。潮下层状和波状叠层石以其色深、纹层密集、缺乏干裂收缩缝和窗格状组构区别于潮间带。锥柱状叠层石出现于潮间带和潮下高能带的上部;潮间带的锥柱状叠层石可能因暴露干裂而继承性地有壁,但潮下带的却可能没有。核形石和凝块石占据着泻湖和水下凹地(生物丘之间的低洼地或废弃潮汐沟道)等低能环境。燕山西段的叠层石罕见于潮上带和波基面之下的潮下低能带。     

富钴结壳成因探讨

富钴结壳（Cobalt-ch ferromanganese crusts）是继多金属结核、锰结核之后被人类发现的又一深海矿产资源，由于其所处深度比锰结核浅，并且战略金属钴的含量较高，因此成为当前国际的研究热点。本文主要从矿物岩石学、地球化学、同位素、生物地层学等方面对成因问题进行了分析。     

小白鼠眼的形态发生的研究

从小白发产胚胎第８ｄ形成视泡开始到发育为成体的眼为止，详细观察和描述了其眼的形态发育变化，实验以视网膜、晶体和角膜的发育为主。结果表明：视网膜的发育从胚胎第８ｄ视泡出现开始，在胚胎第９．５ｄ分化为２层，第１１．５ｄ分化为４层，刚出生时分化为６层，成年已分化完全，具完整的１０层结构；晶体的形态发生经历了晶体板（第９．５ｄ）、晶体凹（第１０ｄ）、晶体囊（第１０．５ｄ）、初级晶体纤维（第１１．５ｄ）及次     

高山雪鸡卵壳及壳膜超微结构的观察

以扫描电镜观察了高山雪鸡（Ｔｅｔｒａｏｇａｌｌｕｓｈｉｍａｌａｙｅｎｓｉｓ）卵壳和壳膜的超微结构。其卵壳由５层构成，由内向外分别是基帽层，乳突层，栅栏层，结晶层和护膜层。气道外孔有益层。栅栏层有少量气泡（Ｖｅｓｉｃｌｅｓ）．壳膜由３层膜构成，外层和中层为纤维膜，内层为非纤维结构的平滑的薄膜。本项观察发现了引导栅栏层形成的钙化桥。     

Ultra-microbes are the minerogenetic constructors of oceanic polymetallic nodules

Polymetallic nodules (mangnese nodules) are a typical kind of manganese oncolites The distribution of smooth sur-face and knobbly manganese nodules is closely related to the geological background of the mine field. A systematic study on their inner laminae structure and features suggests that they are the products of millions of years reproduction and accumulation of the recently found Miniactinomyces chinensis and Spirisophaerospora pacijica .     

Nickel and copper accumplation as essential elements in 10-A manganite of deep-sea manganese nodules

MANY ferromanganese minerals have been found in marine manganese deposits. There have been terminological and intrinsic problems in accurately defining the constituents of manganese nodules(1), but 10-A manganite and delta-MnO(2) which are often compared with todorokite and birnessite seem to be the only major constituents of marine manganese nodules and crusts. [Note that birnessite is a natural species of delta-MnO(2) of four-line form, whereas marine delta-MnO(2) is two-line form, so marine and terrestrial delta-MnO(2) should not be compared directly with each other.] However, there have been few experimental studies of the mechanism of accumulation and the crystallochemistry of these elements in 10-A manganite of manganese nodules, although many experimental studies of adsorption of metals to natural and synthetic manganese and iron oxides have been made(7,8). I have now investigated the mechanism of accumulation of nickel and copper in manganese nodules by synthesising 10-A manganite and comparing the composition with that shown by microscopic and electron microprobe analyses of marine 10-A manganite.     

The role of microbes in accretion, lamination and early lithification of modern marine stromatolites

For three billion years, before the Cambrian diversification of life, laminated carbonate build-ups called stromatolites were widespread in shallow marine seas. These ancient structures are generally thought to be microbial in origin and potentially preserve evidence of the Earth's earliest biosphere. Despite their evolutionary significance, little is known about stromatolite formation, especially the relative roles of microbial and environmental factors in stromatolite accretion. Here we show that growth of modern marine stromatolites represents a dynamic balance between sedimentation and intermittent lithification of cyanobacterial mats. Periods of rapid sediment accretion, during which stromatolite surfaces are dominated by pioneer communities of gliding filamentous cyanobacteria, alternate with hiatal intervals. These discontinuities in sedimentation are characterized by development of surface films of exopolymer and subsequent heterotrophic bacterial decomposition, forming thin crusts of microcrystalline carbonate. During prolonged hiatal periods, climax communities develop, which include endolithic coccoid cyanobacteria. These coccoids modify the sediment, forming thicker lithified laminae. Preservation of lithified layers at depth creates millimetre-scale lamination. This simple model of modern marine stromatolite growth may be applicable to ancient stromatolites.     

Classification of the microbes and study of the beaded ultra-microfossils in pelagic manganese nodules

The pelagic manganese nodules from the East Pacific Ocean have been studied using polarizing and electron microscope since 1994. Based on the surface morphology and the type of stromatolites in the coatings, these manganese nodules can be divided into smooth and knobbly ones. The coatings of smooth nodules are composed of Minima. The coatings of knobbly ones consist of Admirabilis. The authors have reported the first discovery of the beaded ultra-microfossils in the manganese nodules, but did not classify and     

深海锰结核作生物固定化载体处理染料废水

用深海锰结核作生物固定化载体,在气升式反应器内进行了对比实验.结果表明:结核作固定化载体处理废水,可有效地降低废水中的化学耗氧量(COD)、生物耗氧量(BOD)、固体悬浮物(SS)、色度等,并可打开难降解的苯环.固定化微生物脱色机理是载体吸附和细菌降解双重作用.处理后的污水可作为J13菌的有效营养和碳源,作为微生物浸出深海锰结核中有价金属的培养基.固定化微生物在染料废水处理中有实用价值.     

微生物浸出深海多金属结核中有价金属

对氧化亚铁硫杆菌浸出深海多金属结核中有价金属的可行性进行了,着重研究了矿浆浓度、接种量、温度、浸出过程中ＰＨ值对结核中有价金属钴和镍浸出率的影响,同时对氧化亚铁硫杆菌进行了驯化。实验表明,采用Ｌｅａｔｈｅｎ培养基,加入适量黄铁矿作为菌种的营养基质和浸出过程中的还原剂、多金属结核,在常温、酸性环境下,可直接浸出金属铜、钴、镍、锰和铁。     

巢湖地区早三叠世晚斯密斯亚期含鱼化石碳酸盐岩结核的地球化学特征及其地质意义

以安徽省巢湖地区下三叠统和龙山组顶部的黑色泥页岩段及其产出的含鱼化石碳酸盐岩结核为研究对象, 综合岩相学、地球化学(主微量元素和碳、氧同位素)和环境矿物学等分析手段, 探讨富有机质页岩中含鱼化石碳酸盐岩结核的形成机制及可能的地质环境指示意义。结核中心三维保存的鱼化石和较高的碳酸盐含量(80%)表明结核形成于早期成岩阶段, 结核内部呈同心环状结构, 从中心至边缘, 碳酸盐矿物含量降低, 硅质碎屑矿物增多并逐渐出现纹层, Fe和S含量升高、δ¹³C值增高、δ¹⁸O值降低和TOC含量逐渐增多等特征均表明结核为同心生长模式。对围岩中草莓状黄铁矿的粒径分析结果表明, 结核形成于硫化还原环境。结核出现在斯密斯亚阶与斯帕斯亚阶界线(SSB)之下1 m处, 与界线层有机碳埋藏增加、碳同位素组成快速正漂移(δ¹³C = -1.3‰~1.9‰)和水体硫化还原事件吻合, 有潜力作为华南地区SSB的辅助识别标志。     

西藏昂仁湖全新世湖相纹层介形类

西藏昂仁全新世湖相沉积纹层发育,其中分析出介形类4属5种,即为Leucocytherella trinoda、L.sinensis、Eucypris gyirongensis、Candona gyirongensis及Ilyocypris biplicata;介形类在纹层中呈现规律性变化,即深色层与浅色层介形类属种组成一致,定量数据揭示浅色层总丰度均大于深色层。根据介形类生态特征推测,浅色层代表盐度较高的年份沉积。     

柴达木盆地花土沟油区上干柴沟组-下油砂山组碳酸盐岩储层特征

柴达木盆地西部花土沟油区碳酸盐岩主要分布于上干柴沟组的上部和下油砂山组的底部 ,与砂岩、泥岩呈不等厚互层 ,单层厚度 0 .5～ 3m,累计厚度可达 10多米。其中藻纹层灰岩和藻叠层灰岩溶孔发育 ,分布范围广 ,厚度大 ,物性最好 ,是一种特殊的油气储层。藻纹层灰岩和藻叠层灰岩发育于相对稳定的滨浅湖环境 ,其发育规模和储层性质主要受沉积环境的稳定性、早期淋溶程度和晚期胶结充填强度的控制。     

Disruption of retinogeniculate afferent segregation by antagonists to NMDA receptors.

Afferent activity has an important role in the formation of connections in the developing mammalian visual system. But the extent to which the activity of target neurons shapes patterns of afferent termination and synaptic contact is not known. In the ferret's visual pathway, retinal ganglion cell axons from each eye segregate early in development into eye-specific laminae in the lateral geniculate nucleus (LGN). The dorsal laminae (termed laminae A and A1) then segregate further into inner and outer sublaminae that retain input from on-centre and off-centre retinal axons, respectively. Thus, individual retinogeniculate axons form terminal arbors within laminae A and A1 that are restricted to one inner or outer sublamina. We report here that blockade of N-methyl-D-aspartate (NMDA) receptors on LGN cells with specific antagonists during the period of sublamina formation prevents retinal afferents from segregating into 'On' and 'Off' sublaminae. Retinogeniculate axons have arbors that are not restricted appropriately, or are restricted in size but inappropriately positioned within the eye-specific laminae. NMDA receptor antagonists may specifically disrupt a mechanism by which LGN neurons detect correlated afferent and target activity, and have been shown to reduce retinogeniculate transmission more generally, causing LGN cells to have markedly reduced levels of activity. These results therefore indicate that the activity of postsynaptic cells can significantly influence the patterning of inputs and the structure of presynaptic afferents during development.