安徽巢湖—滁州地区中生代构造变形特征   总被引：8，自引：1，他引：8  

刘文灿  李博文  潘宝友  刘玉宝 《现代地质》2001,15(1):13-20

安徽巢湖—滁州地区位于张八岭冲断带的南东侧 ,中生代构造活动十分强烈。早印支期 ,区内以北东—北北东向褶皱和逆冲推覆构造变形为特征 ,形成区内主体构造格架 ,为下扬子构造带的组成部分 ;晚印支期以近南北向挤压作用为主 ,形成北西西—近东西向叠加褶皱构造。燕山期 ,受郯庐断裂构造活动的影响 ,区内断裂活动加剧 ,形成多期不同性质的脆性断裂及其所控制的沉积盆地 (拗陷 )。  相似文献   

利用贝类(Lamprotula)化石碳氧同位素再建山西丁村地区晚更新世气候环境   总被引：3，自引：0，他引：3  

李玉成  黄宝玉  徐永昌 《沉积学报》2001,19(4):648-651

较大的湖泊中的贝类生长线的氧同位素可能记录了季节性的温度变化。对拔氏丽蚌 (楔丽蚌 )Lamprotula(Cuneolamprotula)bazini (Heude)和环带丽蚌 (丽蚌 )Lamprotula (Lamprotula)zonata (Heude)的生长线进行氧同位素研究表明,前者有较强的适应环境变化的能力。δ18O值记录的襄汾地区晚更新世的古温度为 2 0～ 2 4℃至 30～34℃,古降雨量多出现代 2 0 0～ 2 6 7mm,河水排泄不畅,积水成湖。这些结果给人的启示是:全球变暖后,该地区气温可能有较大升幅 ;降雨量的增加有可能在排水不畅地区形成水灾,应注意防患于未然。  相似文献   

综合物探方法在地质灾害调查中的应用研究   总被引：12，自引：1，他引：12  

赵成斌  刘保金  姬继法  李长法  袁宏克 《物探与化探》2001,25(6):464-468

介绍了在地质灾害调查中常用的几种物探方法的适用条件和应用范围,并通过实例展示了各种方法的应用效果。结果表明浅层物探方法应用效果显著,在地质灾害调查中具有较好的应用前景。  相似文献   

中强震前后泉水中砷含量变化特征及其在地震预报中应用的可行性研究     

杨崇义  杨静修  陈兰庆  钟心  张宝  杨仁华 《地震工程学报》1992,14(4):25-31

作者在滇西红河断裂带北段布设了5个泉点,开展了砷含量变化的观测研究。通过近三年的观测,发现泉水中砷含量的变化能较好地反映该地区的中强地震活动,地震前泉水中砷含量明显增高。以澜沧7.6级地震为例,讨论了地震前后地下水中砷含量的异常特征及异常机理,并对其在地震预报中应用的可行性进行了论证。  相似文献   

偏岭石及煅烧高岭石的红外光谱研究   总被引：3，自引：0，他引：3  

鲍学昭  关雅先 《矿物学报》1992,12(4):328-333

通过对偏岭石和相应煅烧高岭石的红外光谱测定,发现偏岭石同煅烧高岭石在结构上有很大的差异。在偏岭石中不存在非晶态SiO_2相,其中Si—O_4四面体同Al—O_6八面体是相互聚合的:煅烧高岭石(600～995℃)中则不同,其中Si大部分是以独立的非晶态SiO_2相存在,而同其中的Al_2O_3相分离。偏岭石同煅烧高岭石的关系是:对偏岭石进行一定温度的煅烧,它可以转变成像煅烧高岭石一样的结构状态。  相似文献   

建立涌水量曲线方程的最小残差法     

鲍新华 《吉林地质》1992,(3)

本文在综述了目前稳定流涌水量经验方程建立方法的基础上,根据最小二乘法原理,提出了一种新的方法—最小残差法,并给出了计算实例。计算表明,最小残差法是建立稳定法涌水量经验方程的一种较好方法,计算过程在微机上易于实现。  相似文献   

Onset and Stability of Thermally-Driven Fluid Convection in a Vertical Rock Crack and Their Implication for Hydrothermal Ore-Forming Processes     

Bao ZhengyuChina University of Geosciences  Wuhan 《中国地质大学学报(英文版)》1992

  相似文献   

偏光显微镜聚敛光系统光路分析   总被引：1，自引：0，他引：1  

包相臣 《矿物岩石》1995,15(2):73-77

通过实验和计算，文章证明了勃氏镜进入显微光路后，可使整个显微镜系统变成望远系统，望远系统接收平行光信号，形成干涉图或偏光图像，而显微系统接收非平行光信号形成矿物像，文章不仅对偏光图和干涉图在显微镜筒中的光路变化及成像机理进行了深入讨论，并且对如何保持干涉图和偏光图像清晰提出了调试意见。  相似文献   

The Evolution of Alpine Ultramafic Rocks and Partial Melting of the Upper Mantle     

Bao Peisheng  Wang Xibin  Hao Ziguo  Peng Genyong Institute of Geology  Chinese Academy of Geological Sciences  Beijing Fei Zhenbi 《《地质学报》英文版》1993,67(1)

Ultramafic rocks of Tibet and Xinjiang are the products of partial melting of the upper mantle. The evolution of their mineral composition is marked by two parallel evolutionary series: one is the progressive increase of the 100 Mg/(Mg+Fe~(2+) ratio of silicate minerals in order of lherzolite→harzburgite→dunite, i.e. the increase in magnesium; the other is the increase of the 100 Cr/(Cr+Al) ratio of accessory chrome spinel in the same order, i. e. the increase in Chromium. The above-mentioned evolutionary trends are contrary to that of magmatic differentiation. The evolution of fabrics of ultramafic rocks is characterized by progressive variation in order of protogranular texture→melted residual texture, symplectic texture and clastophyritic texture→equigranular mosaic texture and tabular mosaic texture. Experiments of partial melting of lherzolite have convincingly shown that the evolution of Alpine ultramafic rocks resulted from the partial melting of pyrolite. Various subtypes of them represent different degrees of partial melting. The vertical zoning marked by more basic rocks in the upper part and more acid rocks in the lower actually belongs to the fusion zoning of pyrolite.  相似文献   

NUMERICAL SIMULATION OF MESOSCALE STRUCTURES OF TYPHOON AND OROGRAPHIC EFFECTS USING MM5^*          下载免费PDF全文

Wang Pengyun 《Acta Meteorologica Sinica》1999,13(4):474-493

The track,landfall,dynamic and thermodynamic and cloud-rain physical mesoscale structures and their evolution of typhoon HERB 1996 in 36 h from 0000 UTC 31 July to 1200 UTC 1 August 1996 were simulated by using the non-hydrostatic mesoscale model MM5.This period covered the process of typhoon HERB landfall at Taiwan and Fujian Provinces.Results show that the model successfully simulated the landfall process of typhoon HERB,revealed the most important characteristics of the mesoscale dynamic and thermodynamic and cloud-rain physical structure during its landfall.The simulated typhoon track was close to the observation.The center of cyclonic circulation simulated at 0000 UTC on 1 August 1996 (24 h integration) was located in shore near Fuqing,Fujian Province at which the typhoon was reported to landfall two hours later.It shows that strong upward motion formed by low level convergence existed in the eye-wall and subsidence at the eye.The wind field shows clear asymmetrical structure near the typhoon center.The cloud and rainband was screw-typed distributed around typhoon center,and consisted of meso-β scale rain cores.During the period of typhoon HERB staying near and passing over Taiwan,the lower cloud was developed in the eye region so that the previous clear typhoon eye on the satellite pictures became fuzzy.Observation shows that the typhoon center was "warm",but the model simulations with higher space resolution show that in the mid-troposphere the region of eye-wall with stronger upward motion and more cloud-and rain-water was warmer than the eye.During the period of typhoon passing over Taiwan and its following landfall at Fujian,the track of model typhoon deviated about 30 km northward (i.e.,rightward) because of the orographic effects of Taiwan Island,but the strength of the typhoon was not affected remarkably.The amount of rainfall on Taiwan in the 36 h simulations was enhanced more than six times by the orographic lifting of Taiwan Mountain.  相似文献