兰州倾斜固体潮潮汐参数的观测研究

本文介绍了兰州形变台FSQ—水管倾斜仪1987—1989年期间观测资料的调和分析结果,讨论了潮汐因子的重复性及其对非潮汐变化的监测能力,分析了气象因素对周日波的影响,並将实测潮汐因子与G—B地球模型理论值进行了比较。     

线性连续变化非弹性介质中地震波射线轨迹与走时研究

地球内部非弹性介质广泛存在,垂向线性连续变化非弹性介质模型具有重要理论与实际意义,本文利用复速度概念推导得到了复速度随深度线性连续变化的非弹性介质中地震波射线轨迹与等时线方程.理论结果表明:在线性连续变化非弹性介质中,射线轨迹呈圆形,等时面的形状为椭圆.最后对射线轨迹与等时线方程的适用性条件进行了讨论.     

新疆塔城地区地震地质特征

托里活断层、达尔布特活断层、独山子—安集海活断层及霍尔果斯—卡子湾活断层是塔城地区主要的全新世活断层，均有过多次古地震活动。自１９７７年以来，４级以上地震活动的空区在裕民县西北。据活断层古地震活动复现期及地震活动围空特点分析，今后１０年北天山或塔城西北可能有发生６级左右地震的危险。     

K-Ar isotopic geochronology of Lianhuashan tungsten mining district,Guangdong Province

Reported in this paper are K-Ar ages of volcanic rocks, biotite-granite and greisen from the Lianhuashan tungsten mine in Guangdong Province. The isotopic dilution method was adopted in this work. Whole-rock isochron ages of the volcanic rocks are in the range 120.4±12.1 m.y. The petrogenetic age of biotite-granite and the minero genetic age of tungsten ore are close to those of the volcanic rocks. The apparent ages of various types of rock in the mining district generally bias towards younger values, which may be attributed to the effects of late thermal events which took place in the circum-Pacific metallogenetic belt.     

甘肃天水地区1654年罗家堡7(1)/(2)级地震构造背景的初步分析

本文从分析天水地区区域地质构造背景出发着重指出,1654年罗家堡7(1/2)级地震发生在天礼盆地中北东向构造与北北西向活动构造交汇所形成的新生代以来沉陷最深的部位。并对1936年天水镇6级地震发生的构造条件以及天礼盆地的成因进行了初步探讨。     

On the conditions of formation of Gushan iron ore deposit

On the basis of its geological characteristics, the Gushan iron deposit should be assigned to volcano-hydrothermal type with hematite-quartz as its principal mineral assemblage. Iron concentration of the ore solution has been estimated from the ratio of hematite to quartz in the ore. By using experimental and thermodynamic data, the solubility of ferro-minerals at elevated temperatures and pressures have been calculated in the system FeO?Fe₂O₃?NaCl?HCl?H₂O. The effects ofT, P, pH,f _{O 2} and total Cl concentration on the solubility of ferrominerals are discussed. Thermodynamic calculations based on presumed physico-chemical conditions for the ore solution are in good agreement with geological observations. The calculation shows that ferro-minerals were deposited at logf _{O 2}=?21～?25, log(m_HCl+m_H+)=?2.5～?3,P=1?0.75 (or 0.5) kb, andT=400°?350°C. It is believed that the original solution was an acid NaCl-bearing solution of magmatic derivation. However, iron in the solution was enriched with falling temperatures by dissolving pre-existing ferro-minerals in consolidated rocks rather than extracting directly from the magma. Either temperature (below 400°C) or pressure decrease may result in the precipitation of ferro-minerals from the solution, but the Fe/Si ratio in the ore is dependent mainly upon pH. The widespread siliceous veins of later stages are a reflection of decreasing acidity of the solution. An increase inf _{O 2} will also favor the deposition of ferro-minerals. The hypabyssal occurrence and the existence of the Huangmaqing sandy shale have contributed greatly to the formation of hematite.     

机载热红外扫描在岩溶水文地质中的应用

<正> 由地面资料评价一个地区地下水的排泄地段,已经有了一套比较成功的方法。然而,地面方法相对来说所需要的时间长,花钱多,尤其是在那些交通不便,人们难以到达的地区。四十年代以来,随着航空地质工作的发展,借助于航空摄影所提供的地形、植被类型、地层产状以及破裂等资料来分析地下水的补给和排泄关系。     

A CASE OF MESOSCALE CONVECTIVE COMPLEX EVOLVING INTO A VORTEX*

A case of mesoscale convective complex(MCC) which evolved into a vortex is documented in this paper.As the MCC entered into the dissipating phase,a well-defined spirally banded structure became visible in the satellite image.The blackbody temperature(TBB) of the residual cold-cloud-shield indicates the vortex existed in the layer from 400 to 250 hPa.According to the upper air analysis,the upper level vortex was an anticyclone.The MCC-generated vortex was visualized in the satellite images because it was located in the subtropical high where the wind field was very weak.     

500毫巴湿位势倾向诊断分析和应用

本文用湿位势倾向方程进行诊断分析,表明,湿大气中差动潜热能平流对500毫巴湿位势倾向有重要影响。日常业务中计算500毫巴层位势倾向,在判断未来低值系统的移动和暴雨落区中,有一定指示意义。     

苏北潮滩湿地不同生态带碳、氮、磷分布特征*

通过对比苏北潮滩湿地不同生态带的表层以及柱状沉积物中总有机碳、总氮、总磷和有机磷含量,并结合不同植被不同植株部位中碳、氮、磷的含量变化,分析了潮滩沉积物中碳、氮、磷的垂向和水平分布特征与规律,探讨了不同生态带以及潮滩植被对碳、氮、磷等生源要素的富集作用。对比分析结果表明:苏北潮滩湿地各生态带对不同的测量指标有着不同的富集作用,互花米草滩的总有机碳、总氮和有机磷含量要远大于其他几个生态带,光滩沉积物中总磷的含量最高; 粒度效应是控制互花米草前缘地带以及互花米草滩沉积物中有机碳和氮分布的一个重要因素,盐蒿和芦苇滩中有机碳和氮的分布更多的是受粒度之外的其他因素影响; 不同生态带表层沉积物中的C/N比值分布,大致可反映其有机物来源的差异,而不同生态带中柱状沉积物中的C/N比值相对接近,很难根据C/N比值大小来对不同生态带中的有机物来源进行判断,这可能是埋藏在柱状沉积物中的有机物更多的受到了早期成岩作用造成的。植被对潮滩湿地中碳、氮、磷的分布有着重要影响,3种物质在互花米草、盐蒿和芦苇中的含量差别不是很大,因此潮滩植被对沉积物中上述3种物质的贡献差别主要是由不同植被的生物量和其所处环境的沉积动力差异造成的。