湘中南推覆构造及其产出的大地构造背景

湖南中南部于中新生代地洼发展阶段发育许多推覆构造,基本特征与发育于地槽褶皱带的阿尔卑斯式推覆构造不同,表现在:数量多,分布广,单个推覆构造规模较小,推覆方向各异,成因类型多。     

基于GIS与面向应用的地质编图方法探讨

基于GIS技术建立地质图空间数据库已经成为当前发展的趋势.以赣东北蛇绿岩带的地质编图为例,在常规地质编图流程基础之上,提出了一套基于GIS与面向应用的地质图编图流程:源数据的准备和收集—地质编图综合性设计—扫描矢量化输入—矢量化编辑—区域编辑—成果图输出,使得研究内容得以清晰的呈现,并大大地提高了工作效率.     

推覆构造的控矿成矿规律——以武当山推覆构造为例

通过对武当山推覆构造与成矿关系的研究,认为在推覆构造中的固体矿产主要分布于推覆体变形强烈的两端和推覆构造的强应变带内。     

湖南小龙门推覆构造的几何样式

该文首次对湖南小龙门逆冲推覆构造的几何样式进行了详细研究,初步建立了逆冲断层的S型新模式。根据中、小型构造的空间分布和岩石变形特征,在推覆体内部划分两个构造带,并分析了下伏岩系的褶雏形态和剖面组合型式。     

武当山推覆构造的几何结构──鳞片叠覆模式

武当山推覆构造由主滑脱面、前缘叠瓦褶断带、中央推覆体带和后缘挤压－伸展带４种构造成分组成。中央推覆体带划分为７个推覆体。各推覆体在平面上呈鳞片状越覆，在剖面上呈送冲叠覆，构成鳞片叠覆的几何模式。     

一门新的交叉学科——构造地球物理学

本文从大地构造学与地球物理学交叉结合的简要历史回顾,阐述了笔者新近提出建立一门新的交叉学科——构造地球物理学的必要性和对地球科学发展的理论与实际意义。从构造地球物理学的定义、理论基础、研究对象、研究任务、研究特点和研究方法等六个方面介绍了这门新学科的基本内容,讨论了构造地球物理学与构造物理学的关系问题。最后,就构造地球物理学的发展方向、开拓性研究领域等问题作了探讨。     

龙门山中段推覆构造的变形特征

论述了龙门山三大推覆体和推覆面的构造变形特征 ,认为耿达 -汶川推覆体为褶皱冲断推覆体 ,映秀 -白水河推覆体为冲断推覆体 ,彭灌推覆体为冲断褶皱推覆体 ,并将其划分为两个次级推覆体 ,而相应的推覆面分别为韧性变形为主叠加后期脆性变形 ;脆 -韧性变形以脆性为主及脆性变形的特征。其形成次序由北西向南东 ,即前展式扩张方式。主要活动时期为印支期和喜马拉雅期     

关于盆地分类问题的讨论

本文分析并总结了以往盆地划分中的各项依据,并在前人分类系统的基础上,按地球动力学观点对盆地类型作了进一步研讨,认为将盆地划分为四大类,即拉张型盆地、挤压型盆地、扭动型企地和直接与升降运动有关的沉降到盆地是适宜的。     

苏南地区逆冲推覆构造的某些特征研究

江苏南部地区的逆冲推覆构造广泛发育。这些逆冲推覆构造的产出具多层次性,其形成与该区不同时代地层内的多套由软弱岩层组成的滑动系统有关。关于逆冲推覆构造存在的证据,许多学者已撰文列述了大量地质事实,此外,在地球物理场上亦有明显反映。逆冲推覆构造上覆系统与原地系统间节理裂隙发育程度上有明显差异。逆冲断层带断层岩由浅至深有由脆性—韧脆性—脆韧性—韧性变形的变化规律,在脆性剪切带内的局部地方存在韧性变形。这些变形特征可通过偏光显微镜下变形矿物的一系列光学现象和透射电子显微镜(TEM)下石英晶体的位错现象得到验证。     

Rodinia裂解与华南微板块形成和演化

介绍了Rodinia研究的历史、现状及主要进展,分析了华南相关地块在Rodinia中的位置以及从Rodinia到Pangea的演化历程.分析结果表明,扬子陆块从Rodinia裂离后,其间在Gondwana形成时,可能发生过湘桂地体、云开地体、浙闽地体、保山地体和腾冲地体的碰撞拼贴造山作用过程.在古特提斯演化阶段,这些地体随古特提斯洋的开启而与扬子陆块裂离,并逐渐形成多岛洋的构造格局,之后又随Pangea的形成而再次与扬子陆块碰撞拼贴增生.因此,Rodinia,Gondwana,Pangea等的形成、裂解和裂离后地体的拼贴增生是认识华南大地构造格局和演化的关键之一.Rodinia应该是华南大地构造研究值得重视的重要课题.     

Characteristics of the crustal structure and hypocentral tectonics in the epicentral area of Nan’ao earthquake (M7.5), the northeastern South China Sea

1918 Nan’ao earthquake (M7.5) occurred in the northeast coastal areas of Guangdong Province. With the seismogeological survey of the epicentral area and history materials analyses, the earthquake epicenter was estimated to locate in the intersection part of the Binhai fault zone (Littoral) and Huanggangshui fault, which strikes NEE and NW, respectively. The activities of the NEE-striking thrust fault and NW-striking extensional fault that were attributed to 1918 Nan’ao earthquake occurred in the Dongshan Island of the epicentral area; they reflected the focal stress field with compression in NW-SE direction and extension in NE-SW direction. The isoseismal contour of seismic intensity X shows a shape of ‘X’ composed of two mutually overlapping ellipses with two axes striking NEE and NW, respectively, and such shape implies that the occurrence of this earthquake is controlled by a pair of conjugate seismotectonic faults constituted by the NEE-striking Binhai fault zone and the NW-striking Huanggangshui fault. The Binhai fault zone is a dominant seismogenic structure, and the NW-striking Huanggangshui fault is the subdominant one. The onshoreoffshore deep seismic profile that crossed the epicentral area and was perpendicular to the strike of the Binhai fault zone was obtained. According to the analyses of the seismic data, the Binhai fault zone is defined as a low velocity zone with SE dip-slip in thecrustal structure section. The Binhai fault zone is a boundary fault between the South China subplate and South China Sea subplate. The crust structure on the northwest side of Binhai fault zone is a normal continental crust with a thickness of 30 km, and the one on the southeast side of the fault zone is a thinning continental crust with a thickness of 25―28 km. The Binhai fault zone is an important seismogenic fault and also is an earthquake-controlling fault. The intersection part between the Binhai fault zone and the low velocity zone of upper crust is advantageous to stress concentration and strain energy accumulation, and presents the deep dynamic conditions for the earthquake’s pregnancy and occurrence.     

南海和东海板块构造演化的几个问题

本文就南海、东海及台湾板块构造演化的若干问题展开讨论。我们认为南海海盆是在被动大陆边缘的基础上张开的，而不是弧后扩张的产物；台湾不是活动岛弧．而是典型的岛弧‘大陆碰撞带，并将台湾与鲁马拉雅地区的构造作了对比；吕宋至台湾的板块边缘显示出板块俯冲至碰撞的转化．南海东缘板块边界演化的基本趋势是．从俯冲到碰撞．进而形成极性相反的新俯冲带．南海海盆终将成为被地块全面包围的残留盆地；南海的开合表现为威尔逊旋回的复杂形式。认为冲绳海槽尚未出现伴有新洋壳形成的海底扩张作用．冲绳海槽是弧后裂陷．而非弧后扩张的产物。     

Temporal and spatial variabilities of sea surface heights in the northeastern South China Sea

Analyses of sea surface height anomalies (SSHA) from Jan. 1993 to Dec. 2001 measured by TOPEX/Poseidon (T/P) satellite altimetry indicate that there are two energy highs of SSHA fluctuations on both sides of the Luzon Strait. The highs centered at (19.5°N, 119.5°E) and (22.0°N, 124.0°E) respectively, are separated by a low energy band in the Strait. Empirical Orthogonal Function (EOF) analysis on the "Far Field" suggests that fluctuations of these two areas are mutually independent. EOF analysis on the "Near Field" shows that SSHA oscillation in the northeastern South China Sea (SCS) is dominated by seasonal variations accompanied with significant intra-seasonal and inter-annual fluctuations. Among which, EOFI and EOF2 reflect 66.7% of the total variance. They are both seasonal but showing three months difference in phase. The basic pattern of EOFI appears to be the seasonal SSHA oscillation centered at (18.0°N, 119.0°E) northwest off Luzon Island, which shows maximums (minimums) in August/Septemb     

The Nd-Sr isotope study of Mesozoic granitoids in Jiangxi Province

Nd-Sr isotopic compositions of 12 Mesozoic granitoids from Jiangxi Province have been reported. They show low-εNd( - 13.8--8.3), high-/Sr(0.71069-0.73981) and old tDM (2087-1635 Ma). Comparison between the Sm-Nd isotopic compositions of the granitoids and those of the basement metamorphic rocks suggests that these granitoids were mainly derived from the metasedimentary rocks. There is an east-west trend Mesozoic granitoid zone with low-tDM from S. Jiangxi to S. Fujian. The origin of these granites was preliminarily discussed.     

Zircon U-Pb SHRIMP ages of high-pressure granulite in Yushugou ophiolitic terrane in southern Tianshan and their tectonic implications

Zircons from two high-pressure granulite samples from the Yushugou ophiolitic terrane, southern Tian shan have been investigated by cathodoluminescence, LA ICPMS and ion microprobe (SHRIMP) for their internal textures, trace elemental compositions and in situ dating. The weighted mean ages of these two samples are 392±7 and 390±11 Ma, respectively, representing the granulite-facies meta morphic age of the ophiolitic terrane, and indicating that the southern Tianshan ocean initiated its northward subduction since the early Devonian.     

皖南高职院校田径课教学现状及对策研究

通过问卷调查法、数理统计法，对皖南5所高职院校田径课教学现状进行了调查研究。针对皖南高职院校田径课教学存在的问题进行了分析，对提高皖南高职院校田径课教学质量提出对策，并通过研究得出结论与建议。