基于概率统计的地震岩相识别不确定性定量评价方法

地震岩相识别能够提供具有不同储层特征的岩相分布信息,对岩相识别的不确定性开展定量评价分析可降低后期油藏建模与储层评价的风险.考虑了地震岩相识别中测井岩相定义、岩石物理建模、井震尺度匹配及地震反演等环节的不确定性对岩相识别的影响,基于概率统计方法,引入熵函数实现了地震岩相识别不确定性定量评价,并结合岩相概率、重建率等多角度综合定量分析不确定性的构成及传递特征,系统地实现了地震岩相识别不确定性评价流程的整体连通.提出了结合属性交绘特征约束反演参数空间,提高地震岩相识别运算效率.模拟数据分析表明利用熵函数可精确实现岩相识别不确定性地定量表征,利用属性交绘特征约束参数空间既大幅度减少运算量,也可降低地震岩相识别的不确定性.     

The stratigraphy of the arenig series in the Aberdaron to Sarn Area,Western Llŷcn,North Wales

A new interpretation of the Arenig succession in the Aberdaron area is presented based on biostratigraphical correlation. A lithostratigraphy based on section correlation is presented, and three subareas are identified, each with a different stratigraphy. The Sarn Formation comprises the basal ‘flaggy’ sandstone unit in all three areas but is diachronous: in the south it underlies a Moridunian fauna whilst north of the Bryncroes fault it comprises the majority of the Arenig succession and is probably Fennian in age. The Aberdaron Formation is restricted to the south and is dominated by laminated siltstone. The Wǐg Member, a mudstone unit at the base with a Mordunian fauna is found only to the east of the Wǐg–Nefyn fault, whilst the breccio-conglomerate Porth Meudway Member, at the top of the formation, is restricted to the west of the fault and is probably Fennian in age. The Arenig–Llanvirn boundary is approximately marked throughout the area by a tufaceous unit termed the Carw Formation. The new correlations require the repetition of the succession by a previously unrecognized NNE–SSW trending fault. The junction with the Mona Complex west of Aberdaron is considered to be predominantly faulted. The two subareas south of Bryncroes are sufficiently similar to suggest both belonged to the same deepening basin, probably initiated in the Moridunian. The absence of the Aberdaron Formation and the development of contemporary shallower water facies to the north is taken to indicate this area lay on the footwall of a normal fault bounding the basin to the northwest.     

蒙古国南戈壁省二叠系岩性组合特征及其与内蒙古银额盆地的对比

蒙古国南戈壁省中蒙边界地区分布多个二叠系大型—特大型煤矿,为一套以砾岩为主的粗碎屑岩和含煤系地层夹火山岩建造。银额盆地周缘地表剖面揭示,二叠系发育一套以海相沉积为主的碎屑岩+碳酸盐岩+火山岩建造。银额盆地希热哈达—赛汗桃来地区的钻井资料揭示其为一套粗碎屑岩+含煤系地层夹火山岩岩性组合,与盆地周缘地表剖面各时代地层的岩性组合均存在巨大差异,而与蒙古国南戈壁省二叠系的岩性组合特征相同。通过中蒙边界地区二叠系地层层序与岩性组合特征的对比,明确了银额盆地希热哈达—赛汗桃来地区钻井资料发现的含煤系地层时代为二叠纪,结合沉积充填特征,对银额盆地二叠纪沉积演化与沉积相平面展布有了新的认识,为银额盆地及邻区石炭纪—二叠纪构造演化的研究提供了新的证据。     

滇西北独龙江花岗岩中浆混包体特征

班公湖-东巧-怒江结合带(南段)西侧的独龙江花岗岩可划分为2个序列。早期序列(龙岗不若序列)富含混杂包体和混成包体。前者包括(石英)辉长苏长岩、辉长岩及辉长辉绿(玢)岩;后者由闪长岩、石英闪长玢岩、安山岩、安山玄武岩组成。从地球化学特征看,这些岩石由同源岩浆分异,并与生成寄主岩石的酸性岩浆混合而成。地球化学图解判别,浆混包体属钙碱性玄武岩系列,形成于岛弧环境,与寄主岩石———龙岗不若序列的生成环境一致。该类包体的存在,进一步证明了独龙江花岗岩早期序列(龙岗不若序列)由壳幔混源岩浆形成。     

火山碎屑岩的百年研究

火山碎屑岩是爆破性火山喷发行为的直接产物,不同的碎屑成分、粒度及结构反映了不同岩相的堆积动力学过程,对火山碎屑岩岩石学和岩相组合的研究发展成了以物理火山学为代表的现代火山学研究体系。作为火山爆发碎屑物质的集合,其中不同成因类型的火山碎屑物往往可以直接对应不同阶段火山作用动力学参数特征。火山碎屑物3个最基本的堆积物成因类型是火山碎屑降落物、火山碎屑流和火山碎屑涌浪。火山喷发时碎屑化过程主要涉及挥发分的出溶和岩浆碎屑化过程以及不同火山流体内部的碎屑化过程。对于岩浆喷发、射汽岩浆喷发以及射汽喷发的直接产物,火山碎屑岩在组成上都包含了岩浆破碎的同源碎屑、火山通道裹进的异源碎屑以及火山流体在地表流动时捕获的表生碎屑。火山碎屑定义为爆破性火山喷发的直接行为产物,而包括坡移、滑坡体、火山泥石流等火山降解过程的表生碎屑与熔岩流在自生、淬碎碎屑化过程产生的碎屑则被定义为火山质碎屑。火山岩岩相的建立,为20世纪80年代后期向火山学研究阶段的转变奠定了基础。在地质研究的基础上探索火山活动过程和控制机制的经验模型、实验模拟和数值模拟研究,其中流体动力学的介入对理解火山喷发的基本过程具有里程碑式的推动意义。由此形成的火山学是研究火山与火山喷发的形成机理、喷发过程和产物特性的科学。     

鄂尔多斯子洲-清涧区山2段沉积相研究

山西组山2段为三角洲前缘亚相沉积,进一步划分为四个微相:水下分流河道、分流间湾、间湾沼泽及席状砂,河道由北向南展布,各沉积期河道的发育具有良好的继承性。     

Open clusters and the galactic disk

It is textbook knowledge that open clusters are conspicuous members of the thin disk of our Galaxy, but their role as contributors to the stellar population of the disk was regarded as minor. Starting from a homogenous stellar sky survey, the ASCC‐2.5, we revisited the population of open clusters in the solar neighbourhood from scratch. In the course of this enterprise we detected 130 formerly unknown open clusters, constructed volume‐ and magnitude‐limited samples of clusters, re‐determined distances, motions, sizes, ages, luminosities and masses of 650 open clusters. We derived the present‐day luminosity and mass functions of open clusters (not the stellar mass function in open clusters), the cluster initial mass function CIMF and the formation rate of open clusters. We find that open clusters contributed around 40 percent to the stellar content of the disk during the history of our Galaxy. Hence, open clusters are important building blocks of the Galactic disk (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Photometric study of the OB star clusters NGC 1502 and NGC 2169 and mass estimation of their members at the University Observatory Jena

In this work we present detailed photometric results of the trapezium like galactic nearby OB clusters NGC 1502 and NGC 2169 carried out at the University Observatory Jena. We determined absolute BVRI magnitudes of the mostly resolved components using Landolt standard stars. This multi colour photometry enables us to estimate spectral type and absorption as well as the masses of the components, which were not available for most of the cluster members in the literature so far, using models of stellar evolution. Furthermore, we investigated the optical spectrum of the components ADS 2984A and SZ Cam of the sextuple system in NGC 1502. Our spectra clearly confirm the multiplicity of these components, which is the first investigation of this kind at the University Observatory Jena (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

The open cluster Berkeley 53

We present a photometric study of the neglected open cluster Berkeley 53. We derived its fundamental parameters, such as the age, the interstellar reddening, and the distance from the Sun, based on BV photometry combined with near‐infrared JHK_S data. The structure and the mass function of the cluster were also studied and the total number of members and the total mass were estimated. The cluster was found to be a rich and massive stellar system, located in the Perseus Arm of the Milky Way, 3.1 ± 0.1 kpc from the Sun. Its age exceeds 1 Gy but it seems tobe very young in the context of its dynamical evolution. The analysis of the two‐color diagrams and color‐magnitude diagrams indicates that the cluster is significantly reddened. However, both methods resulted in different values of E (B – V), i.e. 1.21 ± 0.04 and 1.52 ± 0.01, respectively. This discrepancy suggests the presence of an abnormal interstellar extinction law toward the cluster (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

The role of cluster evolution in disrupting planetary systems and discs: the Kozai mechanism

We examine the effects of dynamical evolution in clusters on planetary systems or protoplanetary discs orbiting the components of binary stars. In particular, we look for evidence that the companions of host stars of planetary systems or discs could have their inclination angles raised from zero to between the threshold angles (39.23° and 140.77°) that can induce the Kozai mechanism. We find that up to 20 per cent of binary systems have their inclination angles increased to within the threshold range. Given that half of all extrasolar planets could be in binary systems, we suggest that up to 10 per cent of extrasolar planets could be affected by this mechanism.