Middle Pleistocene temperate deposits at Dingé, Ille-et-Vilaine,northwest France: pollen,plant and insect macrofossil analysis

Nine cores were taken from a damp depression at Dingé, Ille-et-Vilaine, northwest France. Analyses of the pollen, plant macrofossil and Coleoptera remains preserved in the same organic samples of two profiles suggest a temperate vegetation characterised by a mixed deciduous forest with mesophilous taxa (Carpinus, Fagus, Quercus) followed by a coniferous forest with Pinus and Picea. The determination of plant taxa to species was made either directly through the identification of plant macrofossil remains and pollen or indirectly through the identification of phytophagous Coleoptera specifically related to certain plants. Stratigraphical information derived from pollen, plant macrofossil and insect data indicates that this sequence may be correlated with a temperate episode older than the Eemian and younger than the Holsteinian, possibly the Bouchet 2 (Oxygen Isotope Stage 7c) or Bouchet 3 (Oxygen Isotope Stage 7a) temperate periods or the Landos Interglacial (Oxygen Isotope Stage 9 pro parte). © 1997 John Wiley & Sons, Ltd.     

中国南方中及晚奥陶世岩相古地理

中国南方是指西至金沙江一元江断裂、西北至龙门山断裂、北至城口-房县-襄樊-广济断裂、东北至郯城-庐江断裂、东至黄海和东海、南至南海的中国南方的广大地区，面积约200万km^2。在露头剖面和钻井剖面的地层学和岩石学研究所取得的各种定量及定性资料的基础上，采用单因素分析综合作图法，编制出了中国南方中奥陶统胡乐阶(庙坡阶)和}韩江阶(宝塔阶)以及上奥陶统石口阶(临湘阶)和五峰阶的各种单因素图以及相应的各世的岩相古地理图。在这些古地理图中，有7个主要的古地理单元，即滇西台地、康滇陆、扬子台地、斜坡、江南盆地、东南台地和华夏陆。前5个古地理单元属康滇古地理体系，后两个古地理单元属华夏古地理体系。这些古地理图的最大特征是定量，即每个古地理单元的划分和确定都有确切的定量的单因素图和数据为依据。这种定量的岩相古地理图在我国南方中及晚奥陶世还是首次出现。这种定量岩相古地理图在古地理学中是个重大的进展，对石油、天然气以及其他沉积矿产的预测和勘探有重要的指导作用。最后，对两个古地理体系和7个主要古地理单元在整个寒武纪和奥陶纪各期或世的历史演化进行了较详细的探讨。     

重庆合川自流井组植物化石的发现

描述了发现于合川自流井组东岳庙段的三种似木贼植物化石,即Equisetites flus Harris,E．1ateralis(Phillips)和E．columnaris(Brongn．)Phillips。标本保存良好,依据植物和双壳类化石的分布关系,提出自流井组东岳庙段的时代为早侏罗世晚期至中侏罗世早期。同时,分析了东岳庙段的岩相特征和沉积环境。     

大岭子金矿地质特征及选矿浸出率

大岭子金矿V1矿体赋存于中元古界高黎贡山群变质岩中,受韧性剪切带控制,矿石类型以氧化矿石为主。提出选矿依据。     

上新世中期中国气候的数值模拟分析

使用中国科学院大气物理研究所的全球大气环流模式,曾就上新世中期(距今约3百万年前)气候进行过数值模拟试验,在已有针对全球气候进行分析的工作基础上,集中研究了该地质时期我国气候的变化特征。数值试验结果表明,除了青藏高原地区由于地形海拔高度变化而引起的局地冷却现象以外,上新世中期我国约100°E以东地区地表气温上升4～8℃,升温中心位于江淮流域下游地区; 该经度线以西地区地表气温升幅相对要弱一些,在1～4℃之间。上新世中期年均降水在我国东部地区显著减少,平均减幅在0.5mm/天以上,特别是在长江中游地区; 新疆北部、青海和西藏大部年均降水略有增加,而新疆中部和南部年均降水略有减少。在对流层低层,上新世中期东亚冬季风系统减弱,夏季风系统总体上略有减弱; 在对流层中层,冬季东亚大槽显著减弱,夏季中高纬度地区500hPa位势高度升高。在以上结果中,上新世中期我国气候相对于现在偏暖、东亚冬季风强度减弱得到了代用资料的支持。     

Paleomagnetic constraints on Miocene rotation in the central Japan Arc

We present new Middle Miocene paleomagnetic data for the central Japan Arc, and discuss their implications for Miocene rotation. To obtain a refined paleodirection, we made magnetic measurements on basaltic to andesitic lavas and intrusive rocks from 12 sites in the Tsugu volcanic rocks (ca 15 Ma) in the northern part of the Shitara area, Japan. Significant secondary magnetizations in samples with strong magnetic intensities are interpreted as lightning‐induced components. Mean directions carried by magnetite and/or titanomagnetite were determined for all sites. An overall mean direction with a northerly declination was obtained from dual‐polarity site means for nine sites. This direction is indistinguishable from the mean direction for coeval parallel dikes in the northern part of the Shitara area, and also indistinguishable from the Miocene reference direction derived from the paleopole for the North China Block in the Asian continent. These comparisons suggest little or no rotation or latitudinal motion in the study area with respect to the North China Block since 15 Ma. We obtained a refined early Middle Miocene paleodirection (D = 9.7°, I = 52.5°, α₉₅ = 4.8°; 30 sites) and paleopole (82.0°N, 230.8°E, A₉₅ = 5.6°) for Shitara by combining data from the Tsugu volcanic rocks and a coeval dike swarm. An anomalous direction found at three sites could be a record of an extraordinary field during a geomagnetic polarity transition or excursion. Paleomagnetic data from Shitara suggest that: (i) the western wing of the Kanto Syntaxis, a prominent cuspate geologic structure in central Honshu, underwent a counterclockwise rotation with respect to the main part of the southwestern Japan Arc between ca 17.5 Ma and 15 Ma; (ii) collision between the Japan and Izu–Bonin (Ogasawara) Arcs began prior to 15 Ma; and (iii) clockwise rotation of the entire southwestern part of the Japan Arc had ceased by 15 Ma.     

Building and Testing an <Emphasis Type="Italic">a priori</Emphasis> Geophysical Model for Western Eurasia and North Africa

We construct and evaluate a new three-dimensional model of crust and upper mantle structure in Western Eurasia and North Africa (WENA) extending to 700 km depth and having 1° parameterization. The model is compiled in an a priori fashion entirely from existing geophysical literature, specifically, combining two regionalized crustal models with a high-resolution global sediment model and a global upper mantle model. The resulting WENA1.0 model consists of 24 layers: water, three sediment layers, upper, middle, and lower crust, uppermost mantle, and 16 additional upper mantle layers. Each of the layers is specified by its depth, compressional and shear velocity, density, and attenuation (quality factors, Q _P and Q _S ). The model is tested by comparing the model predictions with geophysical observations including: crustal thickness, surface wave group and phase velocities, upper mantle _n velocities, receiver functions, P-wave travel times, waveform characteristics, regional 1-D velocities, and Bouguer gravity. We find generally good agreement between WENA1.0 model predictions and empirical observations for a wide variety of independent data sets. We believe this model is representative of our current knowledge of crust and upper mantle structure in the WENA region and can successfully be used to model the propagation characteristics of regional seismic waveform data. The WENA1.0 model will continue to evolve as new data are incorporated into future validations and any new deficiencies in the model are identified. Eventually this a priori model will serve as the initial starting model for a multiple data set tomographic inversion for structure of the Eurasian continent.     

超大型会泽富锗铅锌矿复合成因

会泽富锗铅锌矿。是近年老矿山深部找矿取得重大突破的典范,而其成因则是当前研究、讨论的热点。笔者认为该矿之形成,既非“MVT型”,亦非“VMS型”,而是与深部隐伏燕山期酸性岩有关的中温岩浆热液叠加、改造、富化的复成因矿床。自加里东期起长期处于张裂环境。深部昭通．弥勒硅镁层隆起,既是幔源玄武岩（热地幔柱）上涌的前奏,又为深部矿源上升创造畅通空间。与多旋回活动的小江深断裂相沟通的NE向矩形断裂网,是导矿、输矿、储矿的有利构造。继火山热液成矿之后,伴随燕山期褶皱、断裂和深部酸性岩浆的上升,发生第二期叠加矿化．矿石中伴生与酸性岩有关的元素组合．并以与酸性岩有关的锗富集为特征。     

Recent Process in Near-Space Gravity Wave Analysis Based on Satellite Measurements

This article focused on the research progress in the gravity wave analysis based on satellite measurements including MODIS, AIRS, AMSU, MLS, DNB, COSMIC,HIRDLS and SOFIE. Besides, a few ground-based observation results and numerical models were briefly introduced and some cases of joint applications of satellite observations with ground-based observations and numerical models in the gravity waves were listed. In general, the satellite remote sensing data play an important role in the study of the characteristics in near-space environment, which can be applied to analyze the scales of gravity waves induced by different sources, correlations between the instabilities and waves as well as their patterns, the impacts in the climate process, wave-wave interactions and wave-flow interactions with other data.     

安徽东至华龙洞古人类遗址2014~2016年出土的石制品

安徽东至华龙洞遗址发现于2006年,因出土丰富的直立人化石、大量动物化石和石制品而备受学术界关注。本文对2014年至2016年在洞口外发掘出土的54件石制品进行报道,意在揭示直立人在该遗址生存的技术特点和适应行为。华龙洞发育在下古生界寒武系灰岩内,由于后期的坍塌,洞口外和洞口内均保留丰富的堆积物。石制品原料取自周边岩石内的脉石英和磨圆度较高的石英岩和燧石砾石;石制品类型包括石核、石片和石器以及各类剥片和修理石器产生的碎片和断块等;石制品个体以小型居多。硬锤锤击法为剥片主要方法,砸击法次之。石器类型主要为刮削器,此外还有尖状器。石制品组合总体显示早期人类的模式1工业类型。哺乳动物化石组合和初步铀系的年代测试表明,古人类在该遗址活动的时间大致为中更新世中后期。两件石制品的拼合现象和多数动物骨骼表面的砍砸和割切痕迹显示,华龙洞为一处直立人多功能的生存和活动遗址。对遗址的进一步发掘和研究对探讨中更新世中国直立人演化、迁徙和技术演化模式等学术问题具有重要意义。