云南农村土木结构房屋有限元抗震分析

根据2007年6月3日宁洱6.4级地震现场调查结果,对破坏较严重的土坯房建立了地震分析模型。对不同的开间、进深及檐口高的房屋,输入了3类场地超越概率为63%及超越概率为3%的地震波进行了有限元抗震分析。结果表明:墙厚影响不大,墙高的影响较大,墙高增加,破坏性增加;因此建议在满足使用功能的前提下,不增加墙厚,而减少层高对抗震更为有利,最后提出了相应的抗震加固措施。     

A Late Cretaceous mammalian dentary from the Ashizawa Formation (Futaba Group), Fukushima,northeastern Japan

A mammalian dentary discovered in the Coniacian Ashizawa Formation (Fukushima, northeastern Japan) is described. The specimen is a fragment of the horizontal ramus of a left edentulous dentary with five alveoli, the distal four of which are plugged with broken roots. Based on the morphologies of the dentary and the roots, it is considered to be of a therian mammal. This constitutes the first discovery of a Mesozoic mammal in northeastern Japan and highlights the potential for future mammal discoveries in the Cretaceous System in northeastern Japan, which will be significant for disclosure of the mammalian faunal evolution in East Asia during the Late Cretaceous.     

Isolated Archosaur teeth from the green sandstone capping the Coralline Limestone (Bagh Group) of the Narmada valley: Evidence for the presence of pre‐Late to Late Maastrichtian abelisaurids in India

Recent field prospecting in the Cretaceous sequences of the lower Narmada valley has led to the discovery of three isolated archosaur teeth from the upper part of marine Cretaceous rocks of the Bagh Group. The specimens were recovered by surface prospecting from an oyster‐bearing green sandstone bed occurring at the top of the Coralline Limestone (Coniacian) from a site near Phutibawri village, Dhar District, Madhya Pradesh, India. Of the three teeth recovered from this horizon, two are identified with abelisaurid dinosaurs and the third one with an indeterminate crocodile. The abelisaurid teeth conform to the premaxillary and maxillary tooth morphology of Majungasaurus and Indosuchus. Earlier reports of abelisaurid dinosaurs from India are from the Upper Cretaceous (Maastrichtian) Lameta Group of Jabalpur, Pisdura (Central India) and Balasinor (Western India) and Upper Cretaceous (Late Maastrichtian) Kallamedu Formation (South India). As no associated age diagnostic fossils are found, the specimens described here are considered to represent pre‐Late to Late Maastrichtian age based on the known ages of the underlying and overlying formations. The new finds, therefore, document stratigraphically the oldest occurrence of abelisaurid dinosaurs known from the Indian subcontinent.     

强震成组活动与潮汐力调制触发

本文应用构造场体成组震模型的研究结果，探讨了中国大陆Ms≥7．0地震的成组活动的引潮力的调制触发关系。研究表明：我国陆区7级以上强震明显受潮汐力的调制触发，且主要表现为对活跃期内（即成组发生的）7级强震的调制触发。平静期内的7级以上地震基本不受潮汐力触发，而活跃期内82．4％的7级强震发生在受潮汐力触发的月相期，比本底概率高出36．4％。因此，潮汐力的调制触发对于强震活跃期的判断和活跃期内强震的临震（时间）预测有实际意义。文章还分析了潮汐力触发与强震活动的区域动力学环境之间的关系，并用构造场体成组孕震模型讨论了潮汐力对强震活动触发作用的力学机制。     

Discovery of agglutinated foraminifers from the Longzhaogou Group in eastern Heilongjiang Province

The low diversity agglutinated foraminifers are recovered from the Qihulin Formation of the Longzhaogou Group in eastern Heilongjiang, China. The foraminiferal fauna consists of 9 species of 5 genera. The common members are Cribrostomoides nonioninoides (Reuss), Haplophragmoides concavus (Chapman), H. gigas minor Nauss. Although the diagnostic zonal taxa are absent in the agglutinated fauna, according to the global stratigraphic distribution of the above-mentioned species, and the associated Pseudohaploceras ammonite fauna, the foraminiferal fauna may be of a Barremian-Aptian (Early Cretaceous) age.     

西秦岭礼县长安一带西汉水群牙形刺特征及时代讨论

在西秦岭礼县长安一带西汉水群中首次采到牙形刺，计有１７属３６种。根据牙形刺动物群特征、主要种属地史分布及其区域对比，确认该区西汉水群之七固组层位应为上泥盆统法门阶（锡矿山阶），龙鳞桥组主体为费拉斯阶（余田桥阶）底部层位中牙形刺显示中一晚泥盆世过渡色彩。     

Application of visual,statistical and artificial neural network methods in the differentiation of water from the exploited aquifers in Kuwait

The ability of artificial neural network to differentiate water samples from the two aquifers of Kuwait on the basis of their major ion chemistry has been demonstrated. The major ion concentration distribution in the groundwater of the Kuwait Group and the Dammam Formation aquifers of Kuwait appears very similar. Cross-plots, supported by the discriminant function analysis of the data, however, suggest that there are some subtle differences in the overall composition of the water from the two aquifers that make it possible to differentiate the water from the two aquifers in almost 80% of the cases. An artificial neural network improved the differentiation capability to 90% of the cases. It is also possible to estimate the fraction of Kuwait Group water in the flow stream of dually completed wells with the help of an artificial neural network developed for this purpose. Electronic Publication     

长乐-东山构造-岩浆带中北段地质特征

从复杂的构造变形中甄别出岩浆岩的塑性流动变形,与韧性和脆-韧性变形区别,力争还原长乐—泉州沿海一带地质构造的真实面目,并探讨了该带的活动时间和构造属性。另外还对该带长期争论的澳角群进行了初步的分解,锆石SHRIMP测年数据也反映了平潭南务里一带变质岩的复杂性。     

浙江东部火山岩地区的地层时代和划分

通过对浙东地区地层特征与划分、同位素年龄等综合分析,结合近年来的新资料,认为该区前寒武纪地层由太古宙地壳物质再循环重熔结晶形成;芝溪头变质杂岩原岩可能由古元古界八都(岩)群与石炭系—二叠系沉积地层组成,二者共同于晚二叠世—中三叠世发生变质作用;中生代大规模火山岩浆活动主要发生在早白垩世晚期:磨石山群形成于早白垩世晚期,以大规模喷发酸性火山岩为特征;永康群、天台群中的众多地层也主要形成于早白垩世晚期,是不同火山构造盆地(洼地)喷发—沉积的同期异相堆积物或同期同物异名地层,以双峰式火山岩、"红层"为特征。     

湘黔桂新元古代拉伸纪晚期地层年代格架对比及关键地质事件初探

湘黔桂地区发育一套完整的新元古代拉伸纪晚期地层(下江群及其相当地层),是研究扬子克拉通与华夏板块碰撞拼接后华南大陆裂谷盆地演化的重要载体。本文报道了贵州省铜仁市万山区清水江组上部、平略组底部及中部变质凝灰岩和沉凝灰岩的年龄,分别为(763.8±5.5) Ma(N=24,MSWD=0.29)、(760.2±4.1) Ma(N=25,MSWD=0.39)、(759.1±3.9) Ma(N=26,MSWD=0.38)。通过对湘黔桂地区下江群及其相当地层中已有火山岩、火山碎屑沉积岩、含凝灰质岩石年龄的系统梳理与分析研究,进一步确定下江群其及相当地层的沉积时限在822~715 Ma,桂北丹洲群三门街组玄武岩是在武陵造山后伸展背景下湘黔桂地区裂谷最大裂陷时期的产物,清水江组与平略组内大量的火山物质可能来源于江南造山带东段800~760 Ma的中酸性喷出岩。结合地层、岩性、年代特征,本文恢复了湘黔桂盆地新元古代拉伸纪晚期的演化历史,并认为该套地层符合建立下江系条件。