徐家围子断陷深层天然天的形成

通过对松辽盆地徐家围子断陷深层天然气的地质和地球化学分析,揭示了天然气的成因特征和形成过程。该区天然气的分子组成和同位素组成均显示出较大的变化,甲烷是天敢中的主要组分,质量分数在５７．４％－９８．２％之间,平均为９０．１％,主要非烃气体是ＣＯ２和Ｎ２,平均质量分数分别为４．９％和３．２％,且ＣＯ２质量分数变化范围较大,气体同位素分析结果表明,甲烷同位素显示煤型气特征,而乙烷和丙烷的同位素显示油型 的特征,表明徐家子深部除煤和ＩＩＩ型干酪根作为主要气源外,仍有一定含量趋于生油的ＩＩ型干酪根作为次要气源,实测和计算结果证实天然气主要是有机质在高成熟阶段形成的产物,运移过程中和成藏后的次生变化使天然气的组成和同位素面目变得非常复杂,尤其是由盖层微渗漏造成的蒸发分馏的作用使同位素出现例转,徐家围子断陷深层煤型气的发现为     

雅攀路南段小高滑坡成因与发展趋势分析

拟建的雅攀路南段沿线发育了一系列特征类似的滑坡 ,即堆积物沿下伏昔格达组顶面或层面滑动的滑坡。特殊的地层岩性条件是滑坡产生的基本因素 ,地下水活动及河流侵蚀是其诱发因素 ,人类活动是其强化因素 ,地震活动是其潜在诱因。公路的修筑将影响滑坡的稳定性 ,施工中应采取相应措施。     

安徽浮槎山地区片麻岩套特征及成因、时代讨论

根据详细的１：５万地质填图资料,对侵位于阚集（岩）群、肥东（岩）群的变质变形侵入岩组合 ──片麻岩套的岩石特征、岩石化学特征及地球化学特征作了系统的阐述,确认其为一套属于钙碱性 系列的同源演化序列,并对其成因（岩浆起源、构造背景等）、成岩时代（形成于吕梁期、受晋宁期构造变 质叠加改造）作了分析与探讨,为正确认识大别－苏鲁造山带皖中段早期演化提供了重要的地质依 据。     

Spatial and Temporal Gradients of Triazines in the Baltic Sea off Poland

The herbicides atrazine, simazine and terbuthylazine (and the degradation product deethylatrazine) were analysed in two river-to-open-sea transects and two vertical (open-sea) profiles in the southern Baltic off Poland. Samples taken in September 1995 and April 1997 contained total triazine concentrations ranging from 7 to 31 and 4.5 to 13 ng/dm³, respectively. Concentrations of the individual compounds ranged from 0 to 8 ng/dm³. These are generally higher than levels reported, for example, in the North Sea. The largest surface concentrations were found close to the Vistula and Odra river mouths, endorsing river run-off as a primary source of the triazines. Temporal variability can be related to the late-spring and early-summer agricultural applications of the compounds. Variations in ratios between the individual triazines can be explained by usage patterns and differing residence times. Offshore vertical profiles indicate enrichment of the surface layer through atmospheric triazines inputs, highest concentrations above the halocline associated with colloidal organics and lowest concentrations in the bottom waters, probably as a result of particulate scavenging. The influence of the North Sea inflow to the Baltic is also discussed.     

Origin of perylene in ancient sediments and its geological significance

The distributions of polycyclic aromatic hydrocarbons (PAHs) in sediments of three Upper Triassic to Middle Jurassic sedimentary sequences from the Northern Carnarvon Basin, Australia have been investigated. Perylene was found to be a major PAH component in the top Lower to base Middle Jurassic sediments that are immature or at low maturity. Its depth/age profiles are not related to the combustion-derived PAHs that have been believed to be produced during ancient vegetation fires before deposition. This suggests a diagenetic origin for perylene. The concentration of perylene in the sediments is proportional to the amount of terrestrial input, decreasing with distance from the source of land sediments. Its carbon isotope composition is slightly heavier than higher-plant derived PAHs, but still in the range of the terrestrially sourced PAHs including higher-plant PAHs and combustion-derived PAHs as suggested previously. Fungi are proposed to be the major precursor carriers for perylene in sediments based on the facts that (1) perylenequinone structures have been previously suggested to be the natural precursors for perylene; (2) perylenequinone pigments exist in many fungal bodies; (3) fungi have played an important role during geological processes.     

基于新参考系的极移改正

本文利用IAU2000决议中关于CIP的定义阐述了极移坐标系和极移坐标的定义,在总结微分旋转矩阵的性质的基础上给出了极移旋转矩阵的详细推导,结合极移产生的主要原因,详细介绍了目前国际上关于极移模型化工作的最新进展,最后给出了获取极移坐标和TIO位置的方法和途径。     

峡山湖沙坝的现代沉积

以现代沉积考察为基础,结合粒度分析资料,对湖泊中沙坝的沉积特征进行了详细的探讨。研究认为峡山湖沙坝微相分为坝前、坝主体、坝后3个沉积单元。坝前受湖浪作用明显,沉积物以湖浪作用形成的浪成沙和冲洗沙为主,发育滩脊和席状沙沉积体。坝主体沉积物以厚度较大、受湖水及风改造明显的中细沙为主,可进一步细分为坝-滩复合体和坝-沙丘复合体。坝后受坝主体阻隔,丰水期为局限湖湾沉积,枯水期发育沼泽沉积。湖泊中沙坝的形成是在滨浅湖环境中水动力和岸线、地貌等因素的影响下,受湖浪、湖流以及暴露环境下风的改造等共同作用的结果,湖浪所派生的沿岸流对沙坝的演化起着至关重要的作用;丰水期沙坝体接受湖水动力的改造,枯水期沙坝体接受风的改造。     

Discussion on origin of clay minerals in outcropped sandstone from Lower Cretaceous Chengzihe Formation and Muling Formation in Jixi Basin

Clay minerals in the outcropped sandstone from Lower Cretaceous Chengzihe Formation and Muling Formation in Jixi Basin were analyzed by X-ray diffraction. The results show that the clay minerals mainly consist of illite, kaollinite and illite/smectite, which can be divided into two types: kaolinite- and illite/smectite types. The outcropped sandstone occurred in middle diagenetic stage-A on the basis of the clay mineral composition. The development factor of the formation of kaolinite type clay mineral is caused mainly by the organic acid from the coal-bearing formation and mudstone during the diagenesis process in Lower Cretaceous Chengzihe Formation and Muling Formation in the Jixi Basin. The weak hydrodynamic force of sedimentary facies made the sandstone leaching condition poor, which is the reason forming the aggregation of clay minerals of the illite/smectite-and illite types.     

汶川8.0级地震的根源和成因

汶川8.0级地震的主要根源是2005年1月20日出现的太阳宇宙线耀斑引起的宇宙线GLE事件。其成因是：宇宙线环境增强使作用到地球的大量宇宙线在电离层产生电流系,再通过电磁感应在地球内部产生感应电流系,进而在地内铀、钍元素富集区产生燃烧腔,进一步引起地下核裂变燃烧和地下氢聚变燃烧,燃烧腔里面的高温高压最终把燃烧腔的围岩炸裂,从而产生大地震。汶川大地震地区的地下观测资料及地震波层析成像分析证实在汶川大地震震源下确实存在异常高温区。据此,本文提出了预警大地震的一条新思路。     

Petrology of ureilites from Grove Mountains, Antarctica：Constraints on the origins

Ureilites are a common group of achondrites with a high abundance of carbon. They probably have a genetic relationship with chondrites, hence provide an insight into origin and evolution of terrestrial planets. A new meteorite-rich region, Grove Mountains (GRV), was found by the Chinese Antarctic Research Expedition, with discovery of 9834 meteorites. Of 2433 meteorites classified, 9 ureilites have been identified. In this paper, we report petrography of 6 of these ureilites. Four ureilites contain graphite and exhibit triangle conjunction and common reduced margins of olivine. GRV 052382 probably experienced heavy shock metamorphism followed by fast cooling, as indicated by mosaic texture or fine-grained granular texture of olivine. GRV 022931 was highly reduced of these ureilites, with olivine as isolated grains in abundant carbonaceous matrix. All 9 ureilites are monomict, and are classified into subtype II (with medium FeO content, Fa15-18) and subtype I (with high FeO content, Fa>18) based on compositions of the cores of olivine. The diverse mineral compositions and petrography of these ureilites suggest that they are not paired and reveal a multi-event history of the parent body. Partial melting of the parent body produced carbon-rich magma, followed by crystallization of graphite and silicates. Later, graphite was partially inverted to diamond by shock events. Reburial of the shocked debris experienced various degree of thermal metamorphism. Finally, these rocks were excavated from the parent asteroid and ejected into Earth-cross orbit by another impact event.