Pseudotachylyte-Induced Weakness of Plate-Boundary Fault:Insight from the Indus-Tsangpo Suture between India and Asia

Although the Indus-Tsangpo Suture(ITS) is the most spectacular thrust system of continent-continent collision in the world, fundamental questions about its strength evolution and deformation behavior transition remain unanswered. Here we reported, for the first time, frictional melting-induced pseudotachylytes in the intensively deformed felsic rocks along the ITS zone in southern Tibet. This study reveals that pseudotachylytes induced profound weakness of the boundary fault between Indian and Asian plates. The intrinsically low strength of the foliated microlites crystallized from frictional melt or glass(i.e., pseudotachylyte) at seismogenic depths compared with the surrounding coarse-grained quartzofeldspathic rocks in the brittle and semi-brittle regime is sufficient to explain the localization of shear strain, the development of ductile shear zones embedded in strong wall rocks, and the transition from the strong to weak fault behaviors without invoking the presence of high fluid pressure or low friction coefficient metasomatic materials(e.g., smectite or lizardite) within the faults.     

Monthly Extended Predicting Experiments with Nonlinear Regional Prediction. Part II: Improvement of Wave Component Prediction

Based on Chen et al. (2006), the scheme of the combination of the pentad-mean zonal height departure nonlinear prediction with the T42L9 model prediction was designed, in which the pentad zonal heights at all the 12-initial-value-input isobar levels from 50 hPa to 1000 hPa except 200, 300, 500, and 700 hPa were derived from nonlinear forecasts of the four levels by means of a good correlation between neighboring levels.Then the above pentad zonal heights at 12 isobar-levels were transformed to the spectrum coefficients of the temperature at each integration step of T42L9 model. At last,the nudging was made. On account of a variety of error accumulation, the pentad zonal components of the monthly height at isobar levels output by T42L9 model were replaced by the corresponding nonlinear results once more when integration was over. Multiple case experiments showed that such combination of two kinds of prediction made an improvement in the wave component as a result of wave-flow nonlinear interaction while reducing the systematical forecast errors. Namely the monthly-mean height anomaly correlation coe cients over the high- and mid-latitudes of the Northern Hemisphere, over the Southern Hemisphere and over the globe increased respectively from 0.249 to 0.347, from 0.286 to 0.387, and from 0.343 to 0.414 (relative changes of 31.5%, 41.0%, and 18.3%).The monthly-mean root-mean-square error (RMSE) of T42L9 model over the three areas was considerably decreased, the relative change over the globe reached 44.2%. The monthly-mean anomaly correlation coefficients of wave 4-9 over the areas were up to 0.392, 0.200, and 0.295, with the relative change of 53.8%, 94.1%,and 61.2%, and correspondingly their RMSEs were decreased respectively with the rate of 8.5%, 6.3%, and 8.1%. At the same time the monthly-mean pattern of parts of cases were presented better.     

页岩脆性评价岩石物理模型及地震预测

基于页岩低孔、特低渗的储层特征,自然状态下难以获得工业产能,在开采过程中通常需要采取水力压裂等增产改造措施,脆性指标可用于指示岩石易压裂区,因此我们将开展页岩储层脆性特征研究.本文基于扫描电镜及X射线衍射分析实验,对四川某地区龙马溪组岩石样本矿物组成及微观孔隙结构进行分析,结合岩石物理等效介质理论模型对实际岩石进行模拟.根据岩石物理模型构建了关于孔隙度、矿物组分对岩石地震属性及地质力学特性影响的岩石物理模板,分析模板可以得到岩石孔隙度、矿物组分对弹性性质与脆性特征的共同影响,并在此基础上得到了适用于该工区的储层脆性预测新公式.利用测井数据对岩石物理模板进行了对比验证,结果表明模板与测井数据吻合较好,结合地震数据对储层脆性进行了定量预测,对比实际产气结果显示,反演得到的脆性分布结果对储层产气情况具有较好的指示性.     

贵州晚二叠世煤中硫同位素的组成特征

报道了贵州主要开采矿山晚二叠世煤中不同形态硫的同位素组成特征。形成于海水影响较小环境中的煤以低的硫含量,偏正的δ＾３４Ｓ值为特点,形成于海相或受海水影响较大的环境中的煤,则具有高的硫含量和偏负的δ＾３４Ｓ值;在高硫含量的煤中,有机硫和无机硫具有弱的相关性,可能它们具有一致的来源;煤中有机硫的同位素组成对成煤环境是灵敏的,可作为成煤环境划分指标,根据有机硫含量和同位素组成,可分出海水对煤层的影响程度     

海洋天然气水合物的模拟实验研究现状

综述了国内外海洋天然气水合物的模拟实验研究成果及进展，介绍了海洋天然气水合物生成过程中除温度和压力外的各种影响因素及其实验技术，重点讨论了海洋天然气水合物模拟实验研究的实验装置和各种探测技术。引用文献27篇。     

SEDIMENTARY STRUCTURE AND FACIES MODEL OF LATE PLEISTOCENE EOLIAN BIOCAL-CARENITES IN SHIDAO ISLAND OF XISHA ARCHIPELAGO, CHINA

The sequence of biocalcarenites occurred on Shidao Island, the highest one among the Xisha Archipelago, is characterized by the alternation of cross-beddings and parallel beddings, which, owing to the misinterpretation of the sedimentary structures, has caused some controversies.Three kinds of boundary surfaces have been found in the sequence: the first-order boundaries marked with the occurrence of paleosols which is nearly horizontal; the second-order boundaries between dune deposits and interdune deposits, formed by the climbing of the dunes and interdunes under the action of NE-trade wind; and the third-order boundaries of cosets inclining exclusively windward. The dune deposits have well-preserved cross-beddings on a large scale, while the interdune deposits show roughly paralled bedding.In conclusion, the coexistence of the three boundary surfaces and the dune and interdune deposits marks the feature of the eolian biocalcarenites. The eolian deposits started from 3200 yr BP when sea level was low     

比较沉积学的理论与实践

比较沉积学思想是一种新的科学哲学,它的理论基础是自然界的有序性和系统性,相模式是这种有序性和系统性在沉积学中的最佳表现形式.比较沉积学既区别于均变论,又与历史比较法不同.它的产生是沉积学历史发展的必然结果,其核心是模式比较.建立相模式时,既要剔除事件沉积记录,又要注意沉积物的旋回性,将环境作为三度空间的整体加以考虑.     

深切悼念业治铮先生

我国著名的海洋地质学家、教育学家、南京地质矿产研究所名誉所长、青岛海洋地质研究所技术顾问、博士生导师、中国科学院资深院士业治铮教授 ,因病医治无效 ,于 2 0 0 3年 1月 3日 2时 10分在南京逝世 ,享年 85岁。业治铮先生是江苏省南京市人 ,1918年 4月11日生。 1937年考入南京中央大学地质系 ,是年参与成立学生读书会等组织 ,宣传抗日。 1941年9月毕业至 1944年 8月在云南昭通西南矿产测勘处工作。 1944年 9月— 1946年 8月在重庆前中央大学地质系教书。1946— 1949年在美国路易斯安娜州州立大学及密苏里大学研究生院学习 ,获硕士学位 …     

辽东湾中北部浅层埋藏古河道沉积特征及对海上工程的影响

以大量钻孔资料总结出辽东湾中、北部全新世８．５ｋａＢ．Ｐ．以来沉积了第一海相层,与下伏盛冰期的陆相层之间构成不整合界面（Ｒ１）。界面以下的Ｂ层中发育大量理藏古河道,古河道ＮＥ向展布,宽２０～８００ｍ,理深２～１３ｍ,按其理深位置分在４种古河道,按其充填方式又可分成５种古河道。它们在认识地层古环境、海上施工、海上建筑和防灾减灾上有重要意义。