Description and Phylogenetic Position of Dinosaur Eggshells from the Luanchuan Area of Western Henan Province, China     

Kohei TANAKA  Lü Junchang  Yoshitsugu KOBAYASHI  Darla K. ZELENITSKY  XU Li  JIA Songhai  QIN Shuang  TANG Min’an 《《地质学报》英文版》2011,85(1):66-74

Here, we examine 145 dinosaur eggshells from a new fossil locality in the Qiupa Formation (Upper Cretaceous) of the Luanchuan area in western Henan Province, China. The eggshells display elongatoolithid macro- and microstructures, including ridges and nodes on the outer surface, two ultrastructural layers, and an undulatory boundary between the mammillary and continuous layers. A phylogenic analysis shows that the Luanchuan eggshells belong to the ooclade Elongatoolithidae. Within Elongatoolithidae, the thickness ratio of the mammillary layer to the entire eggshell, and the porosity of the Luanchuan eggshells are comparable to the oogenera Macroolithus and Elongatoolithus. There is no direct evidence for the taxonomic identity of the Luanchuan eggshells; however, they were likely laid by oviraptorids based on their phylogenetic position and their similarities with known oviraptorid eggs.  相似文献   

Distribution of heavy metals in soils of Port Harcourt and its environs,Niger Delta,Nigeria   总被引：1，自引：0，他引：1  

Minapuye I Odigi  Lucky O. Ukren  Hycienth O. Nwankwoala 《中国地球化学学报》2011,30(4):415-421

Geochemical evaluation of the distribution of heavy metals in soils of Port Harcourt and its environs in the Niger Delta region is presented in respect of anthropogenic factor and index of geoaccumulation. Sixteen (16) soil samples were collected from two horizons (0-10 cm and 100 cm) from the various grids and analyzed. The geo-chemical analyses showed the vertical and horizontal distributions of heavy metals. The results showed the ranges of the metals determined as follows: Pb (6.86-2.49)×10-6, with an average of 4.63×10-6; Cd (0.05-0.00)×10-6, with an average of 0.02×10-6, As (0.01-0.00)×10-6, with an average of 0.00×10-6. Cu (15.36-10.80) ×10-6, with an average of 13.36×10-6, and V (1.36-0.20)×10-6, with an average of 0.94×10-6. Quantification of the degree of pollution was carried out using anthropogenic factor (AF) and index of geoaccumulation (Igeo). The Igeo values of 0.06, 0.02 and 0.00 for Pb, Cd and As, respectively indicate low-level contamination while Zn (1.14) and V (1.40) show me-dium-level contamination. The sources of contamination are attributed to urbanized anthropogenic activities. The majority of the samples analyzed show that the AF values are less than 1 with the exception of vanadium (V) whose AF values range from 2.73 to 13.60×10-6. Vanadium is more enriched than As, Cd, Pb, and Cu. The order of degrees of anthropogenic contamination and index of geoaccumulation in the soil is V >Zn >Pb >Cu >Cd >AS. Metals were retained near the top soil and their concentrations in the deepest horizons were lower and normal for uncontaminated soils. Metal concentrations in the top soil horizons were significantly related to distance from the industrial and hu-man activities.  相似文献   

Spatial Distribution and Longitudinal Variation of Clay Minerals in the Central Indian Basin     

Anil B. VALSANGKAR 《《地质学报》英文版》2011,85(13):814-825

Grain size and clay mineral distribution up to 45 cm depth in the silty clay sediments from 26 box cores from 10° to 16° S along four longitudes (73.5°–76.5°E) were studied for understanding spatial variability in the Central Indian Basin (CIB). It was observed that the average sand content in the basin is 3.8%, which decreases systematically and longitudinally to 0.3% towards south. The average illite and chlorite major clay mineral abundance also decrease southwards along the four longitudes from 10°S, and show the limit of influence of the Ganges- Brahmaputra river’s supply up to 10° S. However, the average clay content increases from west to east in the basin, and southwards along 73.5°E and either side of the 76.5°E fracture zone (FZ), which strongly suggests the possibility of clay supply due to circulation of Antarctic Bottom Water (AABW) from the south through the FZ. The distribution of four clay minerals along 73° and 76.5° E FZ in the CIB shows dissimilar trends of increase and decrease, and indicate a mix environment in the basin. This study indicates that the FZ in the CIB has an important role in controlling the distribution of clay minerals.  相似文献   

Physical Properties, Morphology and Petrological Characteristics of Pumices from the Central Indian Ocean Basin     

Niyati G. KALANGUTKAR  Sridhar D. IYER  Dandaydayudapani ILANGOVAN 《《地质学报》英文版》2011,85(14):826-839

About 400 pumice clasts collected from the Central Indian Ocean Basin (CIOB) were studied for their morphology and were classified based on their shape and size. A majority of the samples range between <1 cm and 36 cm and in the Zinggs shape diagram plot in the equant and oblate fields. The Corey Shape Factor for most of the samples is close to 0.7, which is common for volcaniclastic material. The physical properties such as density, specific gravity, void ratio, porosity, moisture content and degree of saturation, were determined for 30 pumice samples. Density varies from 0.21 to 0.74 g/cm3 specific gravity 1.84 to 3.27, void ratio 2.21 to 10.67, porosity 67% to 91%, moisture content during sinking 0.44 to 2.35 and degree of saturation varies from 26.5% to 86%. Binocular and electron microscopy studies reveal that 60% of the vesicles are elongated, 30% are spherical and 10% are fibrous. Petrography of the pumices exhibits vitrophyric texture with phenocrysts of feldspars and clinopyroxenes. X-ray diffractrogram and mineral analyses confirm plagioclase to be a major phase, while quartz and orthoclase are not uncommon. Todorokite is commonly present in the ferromanganese oxide coating present over some of the pumices. This paper also delves into some details concerning the controversial origin of the pumices and glass shards in the CIOB.  相似文献   

西藏纳木错现代沉积速率的空间分布特征及近60年来的变化研究   总被引：5，自引：3，他引：2  

王君波  朱立平  汪勇  高少鹏  G.Daut 《第四纪研究》2011,31(3):535-543

利用<'210>Pb和<'137>Ca方法对采自青藏高原纳木错不同位置的8支岩芯进行了现代沉积速率的研究,其中6支岩芯的<'210>Pb<,ex>比活度变化具有较好的记录,而只有位于湖泊开阔深水区的NMCS08-1岩芯显示了<'137>Cs比活度的蓄积峰.结果显示不同位置岩芯的平均沉积速率具有明显的空间差异,自约195...  相似文献   

润滑剂摩擦特性及其对顶管推力和管-土相互作用的影响     

K.  Shou  J.  Yen  M.  Li  胡成超译 《岩土钻凿工程》2011,(2):82-90

润滑剂普遍应用于项管工程中,尤其是在复杂地质条件和长距离顶管中。使用润滑剂的主要目的是减小管土之间的摩擦力,但是定量地确定这两者之间的真实接触情况是十分困难的。测量管-土相互作用的新型技术目前仍然很少并有待进一步发展,所以只能利用间接手段测定管土之间的相互作用,并且这些测量方法的应用基于对工程的定性评价。本研究应用一种简单的试验方法来测定台湾地区最常用的润滑剂的摩擦特性,这些摩擦特性可以用于顶力的估算和直线与曲线顶管中管-土相互作用的数值分析。对顶力的分析结果表明顶力的减小与摩擦系数的减小密切相关,并且润滑剂在曲线顶管中的作用比在直线顶管中略大。此外,对台中科技园中400m长直线顶管工程的研究显示由经验公式得到的顶力估算值比实际要大,这表明由超挖造成的管土之间接触面积的减小对砂砾石地层中顶管施工的影响是非常显著的。  相似文献   

微型顶管中管-土间相互作用的分析     

K.J.Shou  F.W.Chang  黄学刚译 《岩土钻凿工程》2011,(2):96-102

采用物理模型试验和数值模拟的方法对顶管过程中的管一土相互作用进行了分析。在将数值分析与模型试验的结果进行比对校准之后,运用有限元分析程序ABAQUS对顶管过程中的地表沉降、破坏机制和管-土相互作用等问题进行了研究。分析结果表明作用于开挖面上的推力对于顶管是至关重要的：推力过小是造成地表沉降的主要原因;而推力过大则会引成地表隆起。此外,研究结果还表明管道的埋深对于选取合理的推力以及确保开挖面的稳定是十分关键的。  相似文献   

水平定向钻法铺设HDPE管的短期和长期反应     

Abdul  G.  Chehab  Ian  D.  Moore  胡雪译 《岩土钻凿工程》2011,(6):16-20

在水平定向钻进施工设计时,回拖力的估算是一项重要内容。正确估计管道轴囱应力分布对于预测管道的长期性能极其重要。本文展示了HDD不同施工参数对聚合物管和钢管长期和短期反应的影响调查结果。结果表明,应力、应变在管道的整个使用寿命当中持续变化。一些施工参数对短期回拖力以及长期的轴向应力有着显著的影响,并对其使用寿命有潜在影响。这项研究表明,在施工过程中,最大短期轴向应力的一半可以作为长期轴向应力的一种保守措施。  相似文献   

一项大直径PE管道穿越铺设工程的经验教训     

Jey  K.  Jeyapalan  周小龙译 《岩土钻凿工程》2011,(1):20-24

一项水平定向钻进穿越铺设大直径PE管道的工程出现工期拖延、投入猛增的后果,究其原因,主要是有关各方漠视勘察资料、设计草率、不熟悉水平定向钻进的监理工程师拥有过大的权力。  相似文献   

http://www.sciencedirect.com/science/article/pii/S1674987111000181     

Ka-Kheng Tan  Rex B. Thorpe  Zhidan Zhao 《地学前缘(英文版)》2011,2(2):223-235

This study investigates the mechanism of formation of convection plumes of mushroom shape in sub-solidus mantle and their prediction.The seismic-tomographic images of columnar structures of several hundreds kilometers in diameter have been reported by several researchers,while the much cherished mushroom-shaped plume heads could only be found in computational geodynamics(CGD) models and simple small-scale laboratory analogue simulations.Our theory of transient instability shows that the formation of conv...  相似文献