朔黄铁路与沿线地带经济发展   总被引：1，自引：0，他引：1  

张素娟  刘占阳  姚丽芬 《地理与地理信息科学》2003,19(2):70-72

该文分析朔黄铁路的功能及其对沿线地区基础设施建设、商贸旅游业、工农业和城镇发展的影响,提出沿线地区经济发展应采取的措施。  相似文献   

古亚洲与特提斯交汇带盆地群油气资源潜力   总被引：6，自引：1，他引：6  

卢进才  陈践发  郭建军  王洪亮  李玉宏 《西北地质》2006,39(3):39-47

古亚洲与特提斯构造交汇带盆地群发育石炭系、侏罗系(中下统)、白垩系(下统)等多套烃源岩,具有厚度大、分布广、有机质丰度高的特点.石炭系烃源岩有机质进入成熟-过成熟热演化阶段,侏罗系烃源岩有机质已进入大量生油阶段,白垩系烃源岩也处于生油高峰,具有良好的油气成藏的物质基础;区内储集岩发育,石炭-二叠系储集层以低孔隙度、低渗透率为特征,石炭系储集层主要为潮坪-泻湖相沉积的碎屑岩,二叠系储集层为一套河流相粗碎屑岩;侏罗-白垩系储集层物性相对较好,以中孔、中渗,或中孔、高渗为特征,为以河流-三角洲沉积砂体;在石炭-二叠系、中新生代地层中均见到了不同级别的油气显示或获工业油流.存在3种不同的生储盖组合,即①自生自储式组合.②下生上储的间隔式组合.③潜山型组合.预测油气资源量36.85亿t,目前已发现的油气储量仅为1亿t,具较大的勘探潜力.  相似文献   

Inter-Comparison of lO-year Precipitation Simulated by Several RCMs for Asia     

冯锦明  符淙斌 《大气科学进展》2006,23(4):531-542

In phase Ⅱ of the Regional Climate Model Inter-comparison Project （RMIP） for Asia, the regional climate has been simulated for July 1988 through December 1998 by five regional climate models and one global variable resolution model. Comparison of the 10-year simulated precipitation with the observations was carried out. The results show that most models have the capacity to reproduce the basic spatial pattern of precipitation for Asia, and the main rainbelt can be reproduced by most models, but there are distinctions in the location and the intensity. Most models overestimate the precipitation over most continental regions. Interannual variability of the precipitation can also be basically simulated, while differences exist between various models and the observations. The biases in the stream field are important reasons behind the simulation errors of the Regional Climate Models （RCMs）. The cumulus scheme and land surface process have large influences on the precipitation simulation. Generally, the Grell cumulus scheme produces more precipitation than the Kuo scheme.  相似文献   

Cenozoic volcanic rocks in the Belog Co area, Qiangtang, northern Tibet, China： Petrochemical evidence for partial melting of the mantle-crust transition zone     

LAI Shaocong QIN Jiangfeng LI Yongfeng LIU Xin 《中国地球化学学报》2007,26(3):305-311

Neogene volcanic rocks in the Belog Co area, Qiangtang, northern Tibet, are represented by a typical intermediate-basic and intermediate alkaline rock association, with latite-trachyte as the main rock type. The results of chemical analysis are: SiO2=52%–62%, Al2O3>15%, Na2O/K2O>1 and MgO<3.30%. In addition, the volcanic rocks are LREE-enriched with LREE/HREE=10–13, (La/Yb)N=15–19, and show a weak negative Eu anomaly with δEu=0.71–0.89. The close relationship between Mg# and SiO2 and the co-variation of the magmatophile elements and ultra-magmatophile elements such as La/Sm-La and Cr-Tb indicate that this association of volcanic rocks is the product of comagmatic fractional crystallization. The rock association type and lower Sm/Yb values (Sm/Yb=3.23–3.97) imply that this association of volcanic rocks should have originated from partial melting of spinel lherzolite in the lithospheric mantle. On the other hand, the weak negative Eu anomaly and relative depletion in Nb, Ta and Ti reflect the features of terrigenous magma. So the Neogene Belog Co alkaline volcanic rocks should be the result of partial melting of the special crust-mantle transition zone on the Qinghai-Tibet Plateau.  相似文献   

Geology and rare-earth element geochemistry of highly evolved, molybdenite-bearing granitic plutons, Southeastern Desert, Egypt     

Gehad M. Saleh 《中国地球化学学报》2007,26(4):333-344

The field relations, mineralogy, and major and trace elements (including REE analyses of whole-rock samples and minerals) of granites and their associated molybdenite uranium mineralized aplites in Southeastern Desert, Egypt, have been studied. The granites are leucocratic and mostly peraluminous in nature with muscovite increasing at the expense of biotite. The chemical and mineralogical characteristics of the granitic rocks indicate that their melts originated from the LILE-enriched mantle wedge by partial melting and are contaminated by crustal melts, followed by thermogravitational processes. Leucogranites with higher Na2O/K2O ratios from Um Dargag and Um Maiat crystallized under H2O-saturated equilibrium conditions in which the exsolved vapor continuously migrated away. The REE patterns of the granites studied are characterized by LREE enrichments and negative Eu anomalies. In comparison, the potassic aplites and the more sodic leucogranites are depleted in LREE, enriched in HREE and show more remarkable negative Eu anomalies. Allanite and monazite are the most important REE carriers in the granites. These minerals are strongly enriched in LREE, whereas fluorite and xenotime, which are more abundant in the aplites, are enriched in HREE. The average Lu/Ce ratio represents the fractionation trend with respect to HREE. It is 0.71 for radioactive fluorite, and it increases to 1.22 for non-radioactive fluorite. The high REE contents of molybdenite represent re-deposition of the mobilized Mo and REE. Due to the strong control of accessory minerals, the REEs are of limited use in petrogenetic modelling of highly evolved granitic systems.  相似文献   

文安5.1级地震的一些异常特征     

解用明  李非  于春颂  鞠永  韩和平  胡秀娟  乔子云 《华北地震科学》2007,25(4):23-26

对文安5.1级地震的一些异常进行了分析和总结,认为地震逆时针方向迁移可能是地震空间活动的一个基本特征,其可作为背景异常。震前,地磁交汇法出现的异常,再次显示出该方法对地点预测的最大优势,交汇点附近即是未来震中区。这些异常特征对我们认识地震和预测地震都具有一定意义。  相似文献   

"第二届中德景观规划设计高层学术研讨会"在北京大学举行     

李先军 《中国勘察设计》2007,(12):88-89

为推动城市边缘地带的前沿课题和应用研究,并探讨中国和国际上的经验和知识,2007年9月23日,由北京大学景观设计学研究院和德国汉诺威大学建筑与景观学院联合主办的"第二届中德景观规划高层论坛"在  相似文献   

1996～1997年两次7级以上大震的跨越式预报          下载免费PDF全文

郭增建 《地震学报》1998,20(6):659-661

１９９１年我们发现,在通过我国的３５度纬线上,历史上的大震活动具有６０年或６０年倍数时间的间隔,且大震发生的位置多在活动构造与该纬线交汇的地方,其具体发生的季节多在冬夏两季．据此,郭增建和秦保燕（１９９１ａ）以及郭增建等（１９９１）预测了１９９６～１...  相似文献   

西藏高原当雄-亚东地带地壳与上地幔结构和速度分布的爆炸地震研究   总被引：10，自引：1，他引：10       下载免费PDF全文

Institute of Geophysics  Academia Sinica 《地球物理学报》1981,24(2):155-170

本文概述了在西藏高原长达450公里左右的南北向测线上取得九次湖中水下爆炸地震记录的处理结果。通过数字处理、拟合和反演等计算,得出了该地区地壳与上地幔的成层结构和速度分布。 结果表明,该区整个沉积岩层厚约3-5公里,雅鲁藏布江以北到当雄地带,地壳巨厚达70-73公里;江南地区为68-45公里,并逐渐向南翘起。在成层地壳介质中发现下地壳中存在低速层,厚约10公里,速度为5.64公里/秒。分析认为,高原地形与巨厚地壳的形成是印度洋板块与欧亚板块碰撞以及长期挤压和内部物质运移的结果。  相似文献   

GPS技术在杭嘉湖平原地面沉降监测中的应用研究   总被引：1，自引：0，他引：1  

方剑强  来丽芳 《浙江国土资源》2007,(2):48-50

一、引言浙江省杭嘉湖平原位于长江三角洲南翼,西起莫干山东麓,北部、东北部分别与江苏、上海接壤,南濒钱塘江河口和杭州湾,总面积约6490km~2。该区水网密布,地势低平,仅在嘉兴、海宁、澉浦、乍浦等地及西部山前地带有零星残丘分布,海拔在100 m左右；平原区地面高程在2～4m,环太湖周围,地势低洼,高程仅1～2m,长期以来内涝严重。  相似文献