岩块超声波速测试中的震相分析

在岩体质量评价中,岩石样品弹性波速的测定是重要的工作之一。利用超声波在岩石样品中的传播了解岩石的弹性性质,需要充分利用波动中所蕴含的信息,而震相分析则是揭示波动中有用信息的有力手段。在震相分析的基础上,着重介绍了岩石样品中震相识别和走时修正方法,并将此方法应用于某工程的岩体质量评价中,取得了较好的效果。     

1999/2000年夏季南极普里兹湾及湾口区叶绿素a和初级生产力

20 0 0年 1月 1 9日至 2 7日在 70°3 0′E- 75°3 0′E,6 2°S以南的南极普里兹湾近岸陆架区的陆隆向深海区设三条纵断面进行浮游生物现存量、真光层深度和光合作用速率的现场观测。并在冰间湖站 - 1 2进行连续昼夜观测。结果表明 ,观测海区叶绿素 a浓度高值位于近岸海湾、冰间湖和测区中部的陆坡区 ;陆坡中部站 - 6和 - 8,0 - 5 0 m的浅水层为叶绿素 a高值区 (2 .1 6- 5 .0 8μg/dm3 )。各测站平均叶绿素 a浓度 2 5 m次表层 (1 .49± 1 .6 1 μg/dm3 )高于表层 (1 .1 4±1 .1 9μg/dm3 ) ,5 0 m以下更深层的浓度随深度的增加而降低 ,2 0 0 m层叶绿素 a浓度仅 0 .0 3±0 .0 2μg/dm3 。昼夜观测结果表明表层叶绿素 a浓度在南极夏季的午后出现最大值 ,晨间出现最小值 ;2 5 m以浅水层的叶绿素 a浓度明显高于深层水 ,与封冰消融冰藻的释放有关。测区真光层潜在初级生产力为 0 .76 - 1 2 .5 9mg C/(m3· h) ,平均值为 4.0 1± 4.0 7mg C/(m3· h) ;海湾和陆架区现场生产力均超过 1 .5 g C/(m2 · d) ,陆坡、深海区约 0 .5 g C/(m2 · d)。高生产力位于高生物量的近岸海湾、陆架冰间湖区。光合作用同化数在 0 .88- 3 .1 0 mg C/(mg Chla· h)。表层叶绿素a浓度与海水中溶解氧浓度呈紧密相关 (Y=0 .0 5 9X     

Application of the 3D magnetotelluric inversion code in a geologically complex area

The WSINV3DMT code makes the implementation of 3D inversion of magnetotelluric data feasible using a single PC. Audio‐magnetotelluric data were collected along two profiles in a Cu‐Ni mining area in Xinjiang, China, where the apparent resistivity and phase curves, the phase tensors and the magnetic induction vectors indicate a complex 3D conductivity structure. 3D inversions were carried out to reveal the electrical structure of the area. The final 3D model is selected from the inversion results using different initial Lagrange values and steps. The relatively low root‐mean‐square (rms) misfit and model norm indicate a reliable electrical model. The final model includes four types of low resistivity areas, the first ones coincide with the known location of an orebody and further forward modelling indicates that they are not in full connectivity to form a low resistivity zone. The second ones are not controlled by magnetotelluric sites and embody little information of the observed data, they are considered as tedious structures. The third one is near to the regional Kangguer fault and should be treated carefully considering the effect of the fault. The last ones are isolated and existing at a limited level as the first ones, they should be paid more attention to.     

基于国产卫星数据的矿山遥感监测一体化解决方案——以西藏自治区为例

随着高分辨率国产遥感卫星数据的推广应用,矿山遥感监测必将成为该数据的重要应用领域之一。结合西藏自治区矿山遥感监测工作的特点,以资源一号02C(ZY-1 02C)及高分一号(GF-1)卫星影像为数据源,在ArcGIS环境下,提出并实现了从国产卫星遥感数据管理、增强与校正、信息提取、统计分析以及成果图制作等一体化解决方案。该研究成果有助于推进国产卫星遥感数据在矿山遥感监测领域的应用广度和深度,为大规模开展多期次动态矿山遥感监测工作提供技术支持和应用范例。     

Characteristics and developmental mechanisms of mud volcanoes on the southern margin of the Junggar Basin,NW China

Mud volcanoes have provided much meaningful information about the deep Earth and the recent crustal and neotectonic movements in an area for over 200 years. However, the triggering mechanisms have puzzled geologists for a long time. This study investigated the factors controlling mud volcano activity and the triggering mechanisms of mud volcano eruptions on the southern margin of the Junggar Basin, NW China. The Baiyanggou, Aiqigou and Dushanzi mud volcanoes are all located along the Dushanzi Anticline, which belongs to the third anticline belt on the southern margin of the basin. The extensive, thick mudstone at depth provides a wealth of material for the formation of mud volcanoes. Simultaneously, the overpressure serves as the driving force for the eruption of the mud volcanoes. The torsional–compressional stress field created by the collision between the Indian and Eurasian plates not only enhanced the abnormal formational pressure in the region but also lead to the development of extensional faults in the core of the Dushanzi Anticline, which served as the conduits for the mud volcanoes. The continuous collision between the Indian and Eurasian plates and the regional torsional–compressional stress field may largely control the cyclical activity of the mud volcanoes and serve as their primary trigger mechanism. Copyright © 2014 John Wiley & Sons, Ltd.     

Hydrothermal uranium deposits and sulfur isotopes

Research on sulfur isotopes in hydrothermal uranium deposits with acid alterations shed much light on the genetic aspects of hydrothermal uranium deposits. Based on the studies of uranium deposits of different genesis, it is concluded that σ³⁴S of Sulfides in hydrothermal uranium deposits derived from residual magma is within the range of +2‰ ?2.6‰, approximately the same as meteorite sulfur. δ³⁴S of Sulfides in polygenetic hydrothermal uranium deposits is slightly lighter than meteorite sulfur and varies over a restricted range (6.7‰), averaging ?10.15‰. Two intervals can be recognized with respect to sulfur isotopic compositions in palingenetic hydrothermal uranium deposits. δ³⁴S of sulfides formed in diagenesis, autometamorphism and hypothermal stages is similar to meteorite sulfur. On the other hand, at the stage starting from the alteration of uranium mineralization to the formation o uranium deposits and postmineralization the average δ³⁴S is -7.89‰, with a wider range of δ³⁴S variation (13.7‰), which can be attributed to the enrichment of δ³⁴S in palingenetic hydrothermal solutions.     

砂岩侵入体的形成机制分析*

砂岩侵入体是指深水沉积砂体受到外界的触发,并在一定条件下形成超压,致使上覆弱渗透性沉积物等围岩发生破裂,砂体以流化和液化的形式向周围沉积物产生侵入。砂岩侵入体的形成过程为形成超压、盖层破裂、产生液化和流化、发生侵入。差异压实、地震引发的液化、流体的加入和压力传递等多种因素都可以使砂岩中形成超压,当地层压力达到并超过破裂压力时,发生水力破裂,或地震引起上覆地层破裂,超压砂岩发生流化,侵入到低渗透围岩中。大量未固结的深水沉积砂岩、低-非渗透层的快速覆盖、形成超压的机制和触发事件是砂岩发生侵入的必备条件。     

LNAPL 污染土壤介电性质的实验研究——-以石英砂为例

为研究轻非水相液体污染土壤的介电性质,在实验室条件下,利用石英砂( 粒径0. 106 ～ 0. 212 mm) 、柴油和水的混合物模拟LNAPL 污染土壤,采用开口同轴探头法利用高频电磁波( 200 MHz ～ 3 GHz) 在污染土壤中的反射获得介电常数,并分析土壤中油水体积含量变化与相对介电常数的变化规律。实验结果表明: 非饱和状态下石英砂的相对介电常数随着体积含水量和含油量的增大而增大,达到饱和状态后体积含油量的增加对相对介电常的影响不明显; 被污染的非饱和状态的砂样在放置过程中,相对介电常数随着放置时间的延长呈现先增大最后趋于稳定的变化趋势。     

青藏高原北部新生代火山岩岩石化学特征及其构造意义

青藏高原北部东西向展布的以安山岩为主的新生代火山岩带,以黑石湖—亚克错—多格错仁一线为界可分为北侧的钙碱性岩系亚带和南侧的碱性岩带亚带。火山岩明显富钾。其形成与塔里木—柴达木板块向高原的楔入作用有关,是消减带上物质重熔上升的结果。     

新疆温泉及吉木乃地区早石炭世异珊瑚

本文描述的异珊瑚化石是1983年在新疆温泉及吉木乃地区下石炭统上部采集的,有3属11种,其中包括1个新种.它们共同的特点是个体很小,体径仅2—4mm.