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451.
运用David A.White,1988介绍的方法,编制东海陆架盆地西湖凹陷和瓯江凹陷油气成藏组合图。通过图件编制的启示,对两个凹陷成藏主要特征和控制油气规律提出了一些新认识,并确定有利勘探区和勘探对象。 相似文献
452.
长江三峡工程坝址西南约10km的狮子口地区,发育一个长约8km、宽约3km的重力滑动构造系统。它由下伏系统、滑动系统和前缘推挤带构成,是一个典型的多层次滑褶型重力滑动构造。它形成时的温、压条件为130.5~193.7℃和180~230MPa;l;形成深度约5~10km;总体岩层收缩量32.2%;总滑移距离1060m;活动时间上限127.65士38.29万年。它是燕山运动期间南北向挤压体制下,在黄陵背斜东、西两侧应力屏蔽区内派生的近东西向拉伸构造应力场的产物。 相似文献
453.
山东及其沿海地区强震(M≥6)发生的地质构造背景 总被引:5,自引:0,他引:5
本文总结了山东及其沿海地区M≥6级地震发生的地质构造背景,发现山东及其沿海地区强震活动很少发生在新构造单元内部,而是主要集中于新构造单元边界上,活动断裂对强震具明显的控震作用,不同活动时代,不同切割深度断裂,其控震能力不同,活动断裂交汇处是发生强震较多的地方。 相似文献
454.
In this paper,a tropical atmospheric model of relevance to shorts-term climate variations(Wang and Li 1993)is util-ized for study of the development of Madden-Julian oscillation.The model contains an interactive process ofboundary-layer Ekman convergence and precipitation heating.The model is solved by expanding dependent variables interms of parabolic cylindrical functions in the meridional direction and truncating three meridional modes n=0,2,4 forequatorial symmetric solutions.The free wave solutions obtained under long-wave approximation are induced as aKelvin wave and two Rossby waves.After considering the effect of boundary-layer dynamic process,the modifiedKelvin wave becomes unstable in long-wave bands with a typical growth rate on an order of 10~(-6) s~(-1)and an eastwardphase speed of 10 m s~(-1);the most unstable mode is wavenumber one.These theoretical results are consistent with the ob-served Madden-Julian oscillation in equatorial area.For the two modified Rossby waves,one with a smaller meridionalscale(n=4)decays except for extra long-waves;the other with a larger meridional scale(n=2)grows in short-wavebands.This may be relevant to explaining the westward propagation of super cloud clusters in the Madden-Julianoscillation.The theory suggests that the boundary-layer dynamic process is an important mechanism in the develop-ment of the Madden-Julian oscillation. 相似文献
455.
上地幔橄榄岩流变性研究新进展及其地球动力学意义 总被引:2,自引:1,他引:2
本文系深部地幔流性研究进展综述文章之一,重点介绍了近年来国际地球物理学界在涉及橄榄岩上地幔流变性的下述三方面取得的进展:(1)化学环境因素对橄榄石高温塑性的影响;(2)高温高压下水在橄榄石晶体中的溶解度和赋存状态;(3)橄榄石多晶体的变形机制转变,并对由此得出的地球动力学意义作了讨论。 相似文献
456.
457.
A continuous-flow hydride atomic absorption spectrophotometric method has been applied to 32 geochemical reference materials for the determination of selenium. The sample is decomposed with a mixture of nitric, perchloric and hydrofluoric acids. Selenium values obtained in this study are in general agreement with literature values and provide additional certification for these reference materials. The precision of the method is generally better than 5% relative standard deviation. The lower limit of determination of selenium in the sample is 12 ppb. 相似文献
458.
459.
We have surveyed the areal and stratigraphic distribution of tonsteins in Late Permian coalfields of southwestern China over an area of several hundred thousand square kilometers. We studied the relationship between tonstein distribution and sedimentary environment. Based on mineralogical and petrographic data, we have concluded that these tonsteins originated as air-fall volcanic ashes. Following accumulation in the peat swamps, in situ alteration of the vitric and lithic components took place under acidic conditions, leading to the formation of kaolinite.Based on petrologic, mineralogic, and chemical analytical data, we have determined that the application of mineralogic and geochemical criteria for tonsteins may be useful in correlating coal beds, predicting coal qualities and reconstructing related sedimentary paleoenvironmental conditions. 相似文献
460.
Stuart C URen 《Marine pollution bulletin》1983,14(8):303-306
A static renewal toxicity test was conducted to evaluate the response of the copepod Acartia tonsa to bis(tributyltin) oxide (TBTO), the active compound of recently developed antifouling paints. Copepods were individually placed in test tubes containing 4 ml of 0.3, 0.5, 1.0, 1.7 or 3.0 μg l?1 TBTO with acetone and seawater. Thirty copepods were used for each treatment and control condition and all solutions were renewed daily. The 96-h LC50 was 1.0 μg l?1 with a 95% confidence interval between 0.8 and 1.2 μg l?1 TBTO. The 144-h EC50 was 0.4 μg l?1 TBTO which approaches concentrations recently measured in San Diego Bay. Some copepods exposed to 0.3 μg l?1 TBTO became moribund after six days. 相似文献