underlying rock

In this paper the forming mechanism of three lobes pattern on the bottomhole rock surface is studied deeply when the tricone bit is used.

本文对使用三牙轮钻头时在井底岩面上形成三凸起型式的原因进行了深入详细的研究和探讨，同时对三凸起型式存在的一些争议问题进行了较全面的分析和阐述，得到了一些有实际意义的结论，为以后分析和诊断钻头及钻柱在井下的振动特征奠定了理论基

Based on the displacement potentials,and taking submarine rock and soil as elastic half-space and seawater as ideal fluid,anchors as rigid restraints,the theoretical formula of the hydrodynamic pressure on rigid submerged floating tunnels with rigid anchor restraints are derived with plane SV-wave incident from submarine rock and soil.

本文基于位移势函数理论,将海底岩土看作半无限弹性体,海水看作理想流体,锚索看作刚性约束,推导了平面SV波从海底岩土斜入射到与海水的交界面时,受到刚度较大的锚索作用的刚性悬浮隧道所受到的动水压力的理论公式;分析了不同海底岩土参数与平面SV波的不同频率和方向对悬浮隧道所受的动水压力的影响。

The folded basement lithology has obvious zoning characteristics and it varies a lot in different zones.

应用综合物化探技术从地球物理场方面揭示了柴达木盆地具有双重基底结构,上部为褶皱基底,深部存在结晶基底,该基底的厚度变化控制着盆地的隆凹格局;褶皱基底岩性具有明显的分区性,不同分区的基底岩性差异较大,从而造成不同分区具有不同的变形特征,这种分区性受深部结构断裂控制。

to differentiate the basement lithology and determine the fracture position.

文章基于电测深探测深厚沉积盆地基底岩性异常较弱的特点。

Pb and Nd isotopic compositions of the Qilianshan Precambrian basements and granitoids in the western segment of the Central Oro-genie System (COS) of China provide constraints on the northwestern boundary of the Yangtze block.

中央山系西段祁连山带基底岩系和花岗岩类的Pb-Nd同位素组成为限定扬子陆块的西北边界提供限制。

In the middle massif of theQilian Mountains, the Precambrian basement metamorphic series include the Huangyuan Group,the Maxianshan Group, and the Hualong Group and so on.

本文重点研究了中祁连东部变质程度最高(高角闪岩相)的化隆群，对该基底岩系(包括片麻岩和斜长角闪岩)及侵入其中的花岗岩进行了全岩主量元素、微量元素、Sr-Nd-Pb同位素和锆石U-Pb年代学的综合研究。

Based on the new gravity and aeromagnetic data, we have analyzed not only the gravity and aeromagnetic characteristics but also the floor lithofacies structures and the distribution of igneous rocks of the North Yellow Sea in detail.

根据最新的重磁数据,详细地分析了北黄海海域的重磁场特征、构造特征、基底岩相构造和岩浆岩分布。

Understanding ages of basement rocks of Junggar basin is significant to study continental crustal evolution and mineralization in Xinjiang.

以U-Pb和Sm-Nd年代学的基本原理为基础,对东准噶尔荒草坡群下部的肉红色黑云母花岗片麻岩、1:25万纸房幅区域调查报告中划出的“新元古代”塔黑尔巴斯套糜棱杂岩和鲍尔羌吉糜棱杂岩等锆石U-Pb年龄数据作了分析研究;进一步明确了东准噶尔下马崖南小石头泉花岗片麻岩的Sm-Nd等时线年龄数据的地质意义,并结合准噶尔造山带变质岩和花岗岩类Nd模式的统计结果,得到初步结论是:至今还没有任何可靠的年龄数据指出准噶尔盆地的基底岩石具有前寒武纪年龄。

Three sediment cores were for the first time retrieved from the middle of the lake.

为了获取该湖冰后期以来连续完整的环境变化档案,我们在2000年初冬利用湖泊冰封面作为稳固的司钻平台,首次从黄旗海湖中央钻取了三孔高质量湖底岩芯。