变质岩的变质序列分析──以辽河群为例

通过对辽河群岩石中主要变质矿物的观察和研究，以岩石的变形历史作为变质结晶作用的相对时标，确定了矿物生长的时序特征及其演化过程。发现变质与变形既是有密切联系的又是各自独立的地质作用，辽河期的变形作用存在明显的３个变形幕，而辽河期的变质作用是个连续的完整的过程，无明显的热波动。变质作用高峰和变形作用高峰存在时间差。     

Micromorphology of solonetzic horizons as related to environmental events in the Caspian Lowland

Micromorphology of solonetz species with special attention to natric horizon was studied in microcatenas at the Dzhanybek Research Station （northwestern Caspian Lowland）. The solonetzic （natric） horizon is easily identified, and it occurs at varying depths, which are the criteria for subdividing solonetzes into 4 species, namely, crusty, shallow, medium and deep. In this sequence, the depth of humus-accumulative horizons increases, and the upper boundary of salinity manifestations goes down. The following micromorphological features are assumed as typical for natric horizons： angular blocky microstructures with partially accommodated aggregates having sharp boundaries and narrow plane-like packing voids; b-fabric speckled in the aggregates＇ centers and monostriated at their peripheries merging into stress coatings; very few interpedal voids; organo-clay coatings; humus- enriched infillings; no calcite and gypsum pedofeatures. A complete set of ＂natric＂ features was found only in the crusty solonetz; the shallow solonetz lacks only illuviation coatings, while the medium and deep species have several modifications of fabric elements： blocky aggregates have a rounded shape and are penetrated by biogenic channels favoring their further biogenic reworking; plant residues became more abundant and diverse, and blackened tissues occur; illuviation clay coatings evolved into papules; stress coatings gave birth to striated bfabrics, thus maintaining a high plasma orientation. The thin sections of natric horizons made 50 and 20 years ago were examined to study the influence of environmental changes （increase in precipitation and rise of ground water table） on micropedofeatures. The following processes took place： （i） in the topsoil： humus accumulation and biogenic structurization; （ii） in the natric horizon - re-arrangement of clay coatings into micromass b-fabrics; and （iii） in the lower part of the natric horizon - development of pseudosand fabric, calcite and gypsum formation. The trends revealed are in good agreement with the environmental events.     

胶州湾女姑山水域夏季赤潮高发期浮游植物群落结构特征

根据 1998年 5～ 8月夏季赤潮高发期间 ,胶州湾女姑山水域浮游植物群落结构的种群组成特征和演替变化对赤潮的发生和种群变动特点进行初步研究。结果表明 ,夏季女姑山水域的浮游植物主要由硅、甲藻组成 ,硅藻在细胞和物种丰度上都占优势。浮游植物优势种在调查期间出现明显的演替现象 ,水温的升高和营养条件的变化是引起物种演替的主要原因。浮游植物细胞丰度在夏季呈明显的增长趋势 ,从 5月份 6.3× 10 5个cell/m3 增至 8月份的 6.7× 10 6个cell/m3 ;其中 ,由于赤潮的爆发 ,细胞丰度的最高峰出现在 7月份 ,为 1.5× 10 7个 /m3 。在赤潮爆发期间 ,赤潮原因种高齿状藻和中肋骨条藻发生了明显的演替现象 ,不同细胞大小的优势种和营养条件的变化是发生物种演替的主要原因。叶绿素a的浓度和细胞丰度的变化共同反映了赤潮发生的全部过程。     

The Glueckstadt Graben of the North-German Basin: new insights into the structure from 3D and 2D gravity analyses

The structure of the Glueckstadt Graben has been investigated by use of 3D gravity backstripping technique and by 2D gravity and magnetic modelling. Subtracting the gravity effects of the Meso-Cenozoic sediments together with Permian salt reveals a positive residual anomaly within the Glueckstadt Graben. This anomaly includes two local maxima over the Westholstein and Eastholstein Troughs. The 2D gravity models point to the presence of a high-density body within the lower crust of the Glueckstadt Graben. In addition, the results of 2D magnetic modelling indicate that the central part of the high-density body is overlain by an area with high susceptibility. Most probable, the formation of this high-density body is a result of complex poly-phase tectonic history of the study area. Finally, the results of gravity modelling indicate that Permian salt is not homogeneous. 3D gravity analysis and, especially, 2D gravity modelling have distinguished the differences in degree of salt saturation in salt-rich bodies, and elucidate the proportion of Rotliegend salt.     

论文化景观的特性

文化景观是人类活动的产物，文化景观研究是文化地理学的主要研究领域之一，而作为文化景观研究的重要组成部分的文化景观特性研究无疑将推动这一领域研究的进一步发展。运用比较分析方法，根据文化景观的定义，探讨文化景观具有时代性、继承性、叠加性、区域性、民族性等五大特性，并对这些特性进行科学的界定和详细的阐述，展示出这五大特性之间所存在的矛盾统一关系和其内在的紧密联系，进一步说明这些特性的实际意义和利用价值。     

A climatic-limnologic model of diatom succession for paleolimnological interpretation of varved sediments at Elk Lake,Minnesota

Sediment traps placed in the profundal region of Elk Lake, north central Minnesota during the 1979 spring and 1983–84 fall and spring seasons monitored seasonal diatom production for two climatically distinctive periods. The spring of 1979 was one of the coldest and wettest on record. Ice out at Elk Lake was 10 days later than average, and spring circulation was short. Fragilaria crotonensis dominated the late spring and early summer diatom production in association with Synedra and Cyclotella species, perhaps because rates of phosphorus supply were low compared to silica. The winter of 1983–84 was drier than usual, and the early but cold spring of 1984 caused ice out at Elk Lake to be about 1 week earlier than normal. Spring storms promoted a long and full circulation that allowed Stephanodiscus minulutus to bloom, presumably in response to increased phosphorus loading related to deep and vigorous circulation. The two dominant diatoms in Elk Lake, F. crotonensis and S. minutulus may reflect climatic patterns that control lake circulation. The climatically regulated occurrence of these diatoms is generally, but not specifically, comparable to their distribution in lake surface sediments throughout Minnesota. A combination of regional and lake-specific studies on the controls of diatom succession and distribution provides climatic insights for interpreting paleolimnogical records of diatoms.     

层状侵入体韵律层理形成过程的定量模拟——以四川攀枝花层状岩体为例

层状侵入体的韵律层理是一种特殊的岩石构造,长期以来其成因倍受关注,成因假说很多。本文在综合这些观点关于岩浆物理,化学性质的研究,尤其是在岩浆房地对流特征研究成果的基础上,提出了新的成因解释,认为固化带前锋处矿物的结晶,熔浆组分的扩散及固化带前锋本身的推进等３个因素的相互耦合是形成韵律层理的主要机制,这个过程是发生在一定过冷却条件下的,在这种定性认识基础上,笔者提出了旨在对韵律层理形成过程进行模拟计     

察尔汗盐湖察尔汗二级补给系统S3盐层晶间卤水中KCl的分异特征、富集规律及其成因

据ＫＣｌ含量的概率分布特征,晶间卤水分为７个总体。晶间卤水ＫＣｌ,在三级系统内水平分异有２种、剖面分异有５种,二级系统内水平分异呈环带状、剖面分异形式为三级系统内分异形式的组合,垂直分异有１３种;富集的总体为Ⅳ（ｋｃｌ）、Ⅲ（ｋｃｌ）用Ｖ（ｋｃｌ）、三级系统为（８）和（１０）号、部位为固相钾高含处;分异及富集的成因主要为晶间卤水的阶段性淡化。     

全球旋回地层学

全球旋回地层学是指在对全球沉积岩进行综合系统研究之基础上，通过估算沉积盆地中源于物源区的沉积物类型和沉积环境条件变化，来预测地层学特征的一种过程一结果模型。其研究内容包括对全球地质演化时期全球海平面变化、全球气候条件、全球构造运动、全球古地理背景、全球沉积环境特征、全球古生物事件及全球矿产形成过程进行动态模拟，强调古气候在地质记录中的意义，注重沉积记录的全球同时性研究；强调各种事件在沉积作用中的意     

巴西坎波斯盆地和桑托斯盆地油气分布差异及主控因素

巴西坎波斯盆地和桑托斯盆地均为典型的被动陆缘盆地。随着勘探程度的增加和近年来在桑托斯盆地深水区盐下油气的重大发现,坎波斯盆地和桑托斯盆地之间的构造-沉积演化和油气地质特征的差异性越来越明显。通过对坎波斯盆地和桑托斯盆地区域地质特征和油气成藏条件差异性的比较,总结出两个盆地油气分布特征的截然不同。研究表明,盐窗比较发育的坎波斯盆地中已发现的油气主要富集于盐上浊积砂岩,而连续盐岩发育的桑托斯盆地已发现的油气则主要富集于盐下湖相碳酸盐岩。对于盐下层系,连续分布的盐岩和圣保罗高地的发育控制了盐下层系油气的分布;对于盐上层系,盐相关构造的发育则为油气垂向运移提供了有利通道,从而控制了盐上油气藏的形成与分布。