内蒙古东北部激流河花岗岩中包体的特征及成因   总被引：1，自引：3，他引：1  

赵寒冬  韩振哲  赵海滨  牛延宏  马丽玲 《地质通报》2005,24(9):841-847

内蒙古东北部阿龙山地区，沿激流河两岸呈NE向分布的二长花岗岩、花岗闪长岩体中发育暗色微粒镁铁质包体。包体具典型的岩浆结构、淬火结构及针状磷灰石，部分包体中含寄主岩石的钾长石、石英巨晶。包体形态主要呈浑圆状，可见明显的塑性流变特点，与寄主岩石间常呈截然的接触关系，有时呈过渡状、雾迷状。寄主岩石富Si、K，并表现出岩浆演化的特点，包体富Mg、Fe、Ca，贫Si、Al，Na〉K。寄主岩石和包体的稀土、微量元素曲线形态相近，均为左高右低的不对称右倾型、轻稀土富集型，包体Eu微弱亏损，寄主花岗岩的Eu中等—弱亏损。包体与寄主岩石在地球化学特征上既表现出了相似性，也表现出了明显的非同源性特点。这些特征表明早石炭世激流河花岗岩类中的暗色包体是岩浆混合的产物，部分代表了混合岩浆的基性端元。  相似文献   

被遗忘的三角洲--论淮河三角洲的形成与演化   总被引：1，自引：0，他引：1  

哈承祐朱锦旗  叶念军黄敬军  龚建师陆华 《地质通报》2005,24(12):1094-1106

导淮自桐柏，会于淮阴，东入海，是追索淮河三角洲形成的由来。公元1128-1885年史称夺准700年，古淮河入海水道为黄河泥沙堵塞，从此淮河改道经长江入海，遂使淮河三角洲不为人们提起。本文从区域地质构造入手，阐述淮河水系的发展、淮河三角洲的形成与区域第四纪海进、海退、成淡水演化过程，为正确认识淮河尾闾的发展演化提供科学依据，为振兴淮河三角洲，走高附加产值的大农业生态经济体系，构建与长江三角洲互补、互助、互利、互赢的可持续发展做出贡献。  相似文献   

青藏高原东缘鲜水河断裂与龙门山断裂交会区现今的构造活动   总被引：18，自引：1，他引：18  

唐文清  陈智梁  刘宇平  张清志  赵济湘  B.C.Burchfiel  R.W.King 《地质通报》2005,24(12):1169-1172

鲜水河断裂与龙门山断裂交会区具有特殊的构造性质。通过对交会区GPS观测,得到欧亚框架下运动速度场。利用所得的运动速度结果,采用刚性地块假设下的最小二乘法拟合方法,得到川滇、川青、扬子地块运动速度分别为(19.2±2.8)mm/a、(10.7±3.2)mm/a、(9.7±1.6)mm/a,地块运动方向由SE逐渐变成SEE,呈现出顺时针旋卷特征;鲜水河断裂运动速度为(9.3±2.8)mm/a,断裂性质为左旋走滑;龙门山断裂运动速度为(1.2±2.2)mm/a,断裂性质为右旋挤压。  相似文献   

西藏日土南部阿依拉杂岩体的地球化学年代学特征及其构造意义     

许荣科马国桃  郑有业茨邛　雷裕红 《地质通报》2006,25(12):428-1436

冈底斯岩基西段的阿依拉杂岩体含有大量的镁铁质包体,在125万区域地质填图的基础上,系统开展了该杂岩体内的包体和寄主岩石的岩石学、主量元素、微量元素地球化学、锆石年代学的研究工作.确定阿依拉杂岩体的包体具火成结构,包体与寄主岩石存在地球化学差异,但同时二者主量元素、微量元素在比值-比值协变图中呈双曲线或直线变异关系,在共分母比值-比值成分变异图中则呈直线变异特点,包体εNd(t)值在1.6～4.4之间,寄主花岗岩εNd(t)值为-10.2～-1.1,反映了壳幔混源的特征.锆石测年获得眼球状花岗闪长岩的结晶年龄为69.8Ma±0.3Ma,根据杂岩体内强烈的塑性构造变形和杂岩体主要岩性在R1-R2图解、微量元素洋脊花岗岩标准化图解上的判别结果,确定该杂岩体属同碰撞花岗岩,69.8Ma±0.3Ma代表了青藏高原西构造结一带印度大陆和欧亚大陆最初碰撞的时间,与两大陆碰撞有关的底侵作用是青藏高原地壳生长和岩石圈结构改变的重要因素之一.  相似文献   

西藏冈底斯成矿带南缘喜马拉雅早期成矿作用——来自冲木达铜金矿床的Re-Os同位素年龄证据   总被引：19，自引：5，他引：19  

李光明  刘波  佘宏全  丰成友  屈文俊 《地质通报》2006,25(12):1481-1486

采集冈底斯成矿带南部克鲁-冲木达铜金成矿亚带冲木达矽卡岩型铜金矿床的辉钼矿样品进行了Re-Os法精确同位素定年。该矿区辉钼矿的模式年龄介于37.63～41.19Ma之间,6件辉钼矿样品得到187Re-187Os等时线年龄为(40.3±5.6)Ma。该成矿年龄明显早于冈底斯成矿带中带和北带的驱龙、厅宫等斑岩铜矿床和甲马、知不拉、帮浦等矽卡岩型铜铅锌矿床的成矿年龄,而与冈底斯成矿带中广泛发育的碰撞期花岗质岩浆活动的年龄基本一致。据此认为,冲木达铜金矿床形成于喜马拉雅早期,与欧亚-印度大陆碰撞阶段的花岗质岩浆活动密切相关。  相似文献   

Dynamics of buried pipes in abck filled trench     

Y. F. Chin  R. K. N. D. Rajapakse  A. H. Shah 《Soil Dynamics and Earthquake Engineering》1987,6(3)

Dynamic response of pipelines lying in a back-filled trench in a semi-infinite medium is investigated. The pipelines are modelled as circular cylindrical shells of small thickness. The problems associated are the ones of plane strain, in which it is assumed that the waves are propagating perpendicular to the pipe-axes. Since no exact solution is obtainable for the problems considered here, a numerical teahnique that combines the finite element method with multipolar representation of the scattered field is used. Numerical results are presented for the normal displacements, as well as the hoop stress in the pipewall either in the presence or absence of another pipe lying nearby.  相似文献   

Dynamic implication of biomass energy consumption on economic growth in Sub-Saharan Africa: evidence from panel data analysis     

Hamisu Sadi Ali  Siong Hook Law  Zulkornain Yusop  Lee Chin 《GeoJournal》2017,82(3):493-502

The present article examines the dynamic linkages between biomass energy consumption, capital stock, human capital and economic growth across selected Sub-Saharan African countries based on dynamic heterogeneous panels of a mean group (MG) and pooled mean group (PMG) techniques. The finding based on PMG as the preferred method reveals that biomass energy consumption, capital stock and human capital are statistically significant, which means aforementioned variables have positive significant impact on economic growth in the countries studied. When an alternative panel estimation techniques of panel cointegration, dynamic OLS (DOLS) and fully modified OLS (FMOLS) are applied, the result based on panel cointegration technique reveals that biomass energy consumption, capital stock, human capital and economic growth are cointegrated as null hypothesis of most statistics are rejected at 1 % level of significance. The finding based on FMOLS shows that biomass energy consumption, capital stock and human capital positively influences economic growth at 1 % level and same result is obtained from panel OLS. The result based on DOLS however reveals that biomass energy consumption and capital stock are significant at 1 % on economic growth while human capital is insignificant. Considering its positive effect on economic growth with little or no environmental degradation when compared with fossil fuel uses, consumption of biomass energy is more preferable in these countries therefore is the best option to adopt by the policy makers of Sub-Saharan African countries.  相似文献   

Lake ice simulation using a 3D unstructured grid model     

Zhang  Yinglong Joseph  Wu  Chin  Anderson  Joshua  Danilov  Sergey  Wang  Qiang  Liu  Yuli  Wang  Qian 《Ocean Dynamics》2023,73(3-4):219-230

Ocean Dynamics - We develop a single-class ice and snow model embedded inside a 3D hydrodynamic model on unstructured grids and apply it to lake studies using highly variable mesh resolution. The...  相似文献