新疆萨吾尔地区两类花岗岩Nd、Sr、Pb、O同位素特征   总被引：10，自引：0，他引：10  

袁峰  周涛发  杨文平  何立新  范裕  谭绿贵  岳书仓 《地质学报》2006,80(2):264-272

新疆西准噶尔萨吾尔地区森塔斯岩体和沃肯萨拉岩体为I型花岗岩,侵入于早石炭世末,具有偏碱性特点,形成于后碰撞阶段的伸展期或挤压—伸展转变期;阔依塔斯岩体和恰其海岩体为A2型花岗岩,侵入于早二叠世初,形成于后碰撞阶段伸展期张性构造环境中。I型花岗岩和A型花岗岩的Nd、Sr、Pb同位素特征相似,显示出幔源特征,它们是同源岩浆不同演化阶段的产物。两类花岗岩在O同位素以及稀土元素特征上存在明显差异。西准噶尔萨吾尔地区I型花岗岩(森塔斯岩体和沃肯萨拉岩体)以及A型花岗岩(阔依塔斯岩体和恰其海岩体)的发育,进一步证实了晚古生代区内地壳的垂向增生作用。对比研究表明,可以将西准噶尔萨吾尔地区的A型花岗岩归入东准噶尔乌伦古富碱火成岩带。  相似文献   

塔里木北部周缘前陆盆地早二叠世快速迁移与沉积相突变:俯冲板片拆沉的响应   总被引：6，自引：0，他引：6  

张传恒  杜维良  刘典波  汪剑  王梦华 《地质学报》2006,80(6):785-791

塔里木北部周缘前陆盆地发育于泥盆纪末至早三叠世期间,完整地记录了南天山造山带的发育过程。该盆地在早二叠世由复理石盆地转化为磨拉石盆地,同时发生快速南移。同期幔源物质加入,有山根地壳熔融的岩浆活动、南天山造山带的整体隆升、热液成矿作用集中发育和变形、变质作用的激化使俯冲岩片的拆沉成为盆地转化与迁移的最佳机制。相同的转化过程及深部机制在其他造山带中也明显存在,表明俯冲岩片拆沉是造山作用一个不可或缺的环节。  相似文献   

西藏普兰石英岩中发现41亿年碎屑锆石   总被引：8，自引：0，他引：8  

温春齐  多吉  范小平  郭建慈  倪志耀  李小文  石玉若  温泉 《地质学报》2006,80(9):1249-1251

在西藏普兰县石英岩中,利用SHRIMPU-Pb法测年发现4.1Ga碎屑锆石。该年龄为目前中国最老单颗粒碎屑年龄。>4.0Ga锆石两测点的Th/U值介于0.76~0.86之间,属岩浆锆石。这一发现,为研究青藏高原的地质演化提供了重要的年龄数据。  相似文献   

白云鄂博矿田碳酸岩墙年代学再研究   总被引：9，自引：0，他引：9  

刘玉龙  陈江峰  李惠民  肖国望  张台荣 《地质论评》2006,52(3):415-422

白云鄂博地区发育侵入于白云鄂博群的碳酸岩墙。碳酸岩墙(00BYC19)中锆石的SHRIMPU-Pb下交点年龄为1984±180Ma,其ID-TIMS上交点年龄为2085±330Ma。碳酸岩墙(02BY80)中锆石SHRIMP的上交点年龄为2035±51Ma;02BY81中锆石的ID-TIMS上交点年龄为1934±64Ma。主矿北碳酸岩墙(00BYC21)的全岩Pb-Pb等时线年龄为1236±300Ma。本文及前人对白云鄂博地区的碳酸岩墙的定年结果表明该地区碳酸岩墙至少有两个阶段的侵入事件,第一阶段在2.0Ga左右,第二阶段在1.2Ga左右。前者是白云鄂博地区以至阴山地块北缘的一次主要的构造—岩浆事件,标志白云鄂博裂谷和白云鄂博群地层的形成。第二阶段的碳酸岩墙,代表白云鄂博裂谷在中元古代的活化,且与成矿有密切关系。  相似文献   

Chemical Composition of Ancient Celadon Material （1127-1279 A.D.） from Zhejiang, China and Its Implication     

PENG Zicheng LEUNG Po Lau YU Peter CHENG Peikai LI Mai 《《地质学报》英文版》2006,80(5):759-762

The microprobe EDXRF equipment was used for analysis of the major and trace elements in glaze layer-transitive layer-body layer of the celadon from the Altar Yao （Kiln） and Laohudong Yao in the Southern Song Dynasty （1127-1279 A.D.）, Zhejiang, China. The K values of the discriminant factor for the celadon wares are larger than 8, which means the celadon of the Altar Yao and Laohudong Yao are different from that of the Longquan Yao. The former two belong to the Guan Yao system （the Chinese imperial kilns）, but the latter to the Min Yao system （the Chinese popular kilns）. The principle component analysis shows their relationship between the Altar and Laohudong wares with provenance postulation. The thickness of the transitive layer in the Altar and Laohudong wares is obviously different, which reveals the microstructure characteristics of the celadon even though both kinds of wares belong to the imperial kiln system.  相似文献   

A Nonlinear Model of Surf Beat     

Nicholas Dodd 《中国海洋工程》1995,(2)

A nonlinear short-wave-averaged (surf beat) model is presented. The model is based on that of Roelvink (1993), but the numerical techniques used in the solution are based on the so-called weighted-averaged flux (WAF) method (eg Watson et al., 1992), with time-operator splitting used for the treatment of some of the source terms. This method allows a small number of computational points to be used, and is particularly efficient in modelling breaking long waves. The short-wave (or primary-wave) energy equation is solved using a more traditional Lax-Wendroff technique. Results of validation indicate that the model performs satisfactorily in most respects.  相似文献   

Micromorphological-investigation on the Earth's Critical Zone     

Ahmet Ruhi Mermut 《山地科学学报》2009,(2):I0002-I0002

Soils, the Earth＇s Critical Zone, play a vital and fundamental role in the Earth＇s terrain eco- environment system and human life. Although the concepts of soil/quality and sustainable development have been introduced for decades, we are still failing to understand how well soils function and they need tobe cared and protected. We have been increasingly witnessing and becoming the victim of shrinking forests,  相似文献   

A Global Reliability Assessment Method on Aging Offshore Platforms with Corrosion and Cracks     

嵇春艳  李珊珊  陈明璐 《中国海洋工程》2009,23(2):199-210

Corrosion and fatigue cracks are major threats to the structural integrity of aging offshore platforms. For the rational estimation of the safety levels of aging platforms, a global reliability assessment approach for aging offshore platforms with corrosion and fatigue cracks is presented in this paper. The base shear capacity is taken as the global ultimate strength of the offshore platforms. It is modeled as a random process that decreases with time in the presence of corrosion and fatigue crack propagati...  相似文献   

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郑作亚  党亚民  卢秀山  郭金运  阳凡林 《大地测量与地球动力学》2009,29(5):107-111

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Predicting size effect on diffusion-limited current density of oxygen reduction by copper wire     

芦永红  徐海波  王佳  钟莲 《中国海洋湖沼学报》2011,29(1)

The size effect of copper wire radius (0.04–0.82 mm) on the diffusion-limited current density of an oxygen reduction reaction in stagnant simulated seawater (naturally aerated 0.5 mol/L NaCl) is investigated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) and compared with the results obtained in 0.5 mol/L H2SO4. In the oxygen diffusion-limited range, size effect is found to occur independent of electrolytes, which is attributed to non-linear diffusion. Additionally, to sati...  相似文献