Evaluation of the Importance of Model Features For Cyclic Deformation Due to Dip-Slip Faulting   总被引：1，自引：0，他引：1  

Steven C. Cohen 《Geophysical Journal International》1994,119(3):831-841

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河西—祁连山地区近期形变场演化特征与孕震构造模式   总被引：2，自引：2，他引：2  

王庆良 《地震》1994,(3):64-71

本文通过对河西－祁山地区近２０年形变场演化特征的分析，提出了代表该区区域应力松驰、岩石圈底部软流层对流加速以及地壳中上部应力强化与强震孕育三种应力状态的特征性形变图象，文章还通过典型强震构造组合特征、形变场特征的分析，提出了该区北西西、北东向两组构造的组合孕震模式，并利用上述孕震模式对该区近期强震危险地点进行了初步判定。  相似文献   

Deglacial land emergence and lateral upper-mantle heterogeneity in the Svalbard Archipelago—I. First results for simple load models     

Doris Breuer  Detlef Wolf 《Geophysical Journal International》1995,121(3):775-788

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Study on Eogene Basalts: Implication of the Deep Process over the Bohaiwan Basin Evolution     

Ye Delong Lu Fengxiang Zhu Qinwen Zheng JianpingFaculty of Earth Sciences  China University of Geosciences  Wuhan  《中国地质大学学报(英文版)》1997,(1)

ＳｔｕｄｙｏｎＥｏｇｅｎｅＢａｓａｌｔｓ：ＩｍｐｌｉｃａｔｉｏｎｏｆｔｈｅＤｅｅｐＰｒｏｃｅｓｏｖｅｒｔｈｅＢｏｈａｉｗａｎＢａｓｉｎＥｖｏｌｕｔｉｏｎ＊ＹｅＤｅｌｏｎｇＬｕＦｅｎｇｘｉａｎｇＺｈｕＱｉｎｗｅｎＺｈｅｎｇＪｉａｎｐｉｎｇＦａｃｕｌｔｙ...  相似文献   

大陆、海洋分布的对称性及成因探讨     

随启发 《华南地质与矿产》2007,(3):75-78

通过观察地球表面偶然发现,大陆、海洋的分布有明显的对称特征,地球一侧如为大陆,与其对应的地球的另一侧一定为海洋。依大陆、海洋分布的对称特征为基本论据,从大陆、海洋形成所需物质、物质运移、物质运移能量三大要素入手,分析讨论了大陆、海洋的形成过程,指出大陆、海洋的形成是靠地球内能的作用,形成大陆的物质来自地球另一侧与其对称分布的海洋,软流层是物质运移通道。  相似文献   

青海西秦岭地区晚中生代基性火山岩地球化学特征及构造意义   总被引：4，自引：0，他引：4  

范立勇  王岳军  李晓勇 《矿物岩石》2007,27(3):63-72

对青海省同仁县多禾茂地区火山岩进行系统的元素同位素地球化学研究表明:该地区白垩纪地层中发育的中基性火山岩,属于碱性火山岩系,岩石类型主要为玄武岩,该套玄武岩具有低且变化较小的Si O2质量分数(44.98%~48.20%),低MgO的质量分数高,变化较大(8.15%~10.98%),具有较高的Cr(208×10-6~418×10-6)和Ni(166×10-6~231×10-6)质量分数。所有样品都表现出轻稀土富集的右倾平滑分布模式,轻重稀土分异中等,(La/Yb)CN=10.09~27.2,重稀土弱分异,(Gd/Yb)CN=2.92~4.67,Eu异常不明显,Eu*/Eu=0.99~1.04。Ba,Nb-Ta和Th-U不亏损,Rb,K相对亏损,Sr正异常。该区火山岩具有亏损的Sr-Nd同位素组成,Sr-Nd同位素组成变化范围不大[87Sr/86Sr(t)=0.7033~0.7039,εNd(t)=6.13~8.03,t=110 Ma],与Hawaii-OIB的Sr-Nd同位素组成相似。其所有地球化学特征表明该火山岩具有类似OIB的特征,可能是含石榴子石橄榄岩低度部分熔融的产物。结合对西秦岭地质构造背景和演化历史的分析,暗示该地区晚中生代岩浆源区来源于软流圈,其起源可能与岩石圈拆沉作用,软流圈地幔上涌和岩石圈伸展减薄有关,可为秦岭大别造山带中生代岩石圈演化提供了有利的直接证据。  相似文献   

Helium and argon isotopes of the Tertiary basic igneous rocks from Shandong Peninsula and implications for the magma origin   总被引：2，自引：0，他引：2  

TANG HuaYun  ZHENG JianPing?  CHEN HongHan & YE XianRen State Key Laboratory of Geological Processes  Mineral Resources  Faculty of Earth Sciences  China University of Geosciences  Wuhan  China  Faculty of Earth Resources  China University of Geosciences  Wuhan  China  State Key Laboratory of Gas Geochemistry  Institute of Geology  Geophysics  Chinese Academy of Sciences  Lanzhou  China 《中国科学D辑(英文版)》2007,50(7):1021-1032

Helium (He) and Argon (Ar) isotopic compositions of the Tertiary basic igneous rocks were determined by the high temperature melting extraction method. The selected samples for the studies included al-kaline basalts and diabases from the Jiyang basin,and the surrounding Shanwang and Qixia outcrops in the Shandong Peninsula,eastern China. The results show that the Paleogene basalts and diabases from the Jiyang basin yielded a wide range of P4 PHe abundance of (73.70-804.16)×10 P-8 Pcm P3 P STP·g P-1 P,with P3 PHe/ P4 PHe ratios of 0.374-2.959 Ra,which was lower than the MORB but evidently higher than the con-tinental crust value. The Neogene alkaline basalts from the Jiyang basin,Shanwang and Qixia outcrops have variable P4 PHe abundances ((42.34-286.72)×10-8 Pcm P3 P STP·g-1 P),and "continental crust-like" P3 PHe/ P4 PHe ratios (0.013-0.074 Ra). All of them contain atmospheric-like P40 PAr/ P36 PAr ratio (395.4-1312.7),reflecting the mantle sources with air components. Their low P3 PHe/ P4 PHe ratios are interpreted as the enrichment of the radiogenic P4 PHe mainly inherited from the mantle. He and Ar systematics show the mixing of MORB-type,air and a P4 PHe enriched member in the mantle source,suggesting that these igneous rocks originated from the depleted asthenospheric mantle mixed with an EMI component. Therefore,the present He and Ar isotopes do not support the viewpoints that the Cenozoic igneous rocks of Eastern North China were the products of mantle plume(s) activities.  相似文献   

再论纬向正常密度假说与内波假说的比较   总被引：1，自引：0，他引：1  

郝晓光  方剑  柳林涛  刘根友 《地球物理学进展》2007,22(1):312-316

本文对“纬向正常密度假说”和“内波假说”再次进行了讨论，进一步比较了二者的联系和区别.根据岩石圈板块概念和地幔对流假说的基本观点、以及“纬向正常密度假说”和“板块运动重力机制”的基本观点，提出了“软流圈板块”概念.  相似文献   

Upper mantle beneath foothills of the western Himalaya: subducted lithospheric slab or a keel of the Indian shield?   总被引：1，自引：0，他引：1  

L. Vinnik  A. Singh  S. Kiselev  M. Ravi Kumar 《Geophysical Journal International》2007,171(3):1162-1171

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Early J₂ basalts in SE China: Incipience of large-scale late Mesozoic magmatism   总被引：1，自引：0，他引：1  

Xie Xin  Xu Xisheng  Zou Haibo  Jiang Shaoyong  Zhang Ming  Qiu Jiansheng 《中国科学D辑(英文版)》2006,49(8):796-815

Magmatism in SE China was dormant during 204–180 Ma, but was reactivated in 180–170 Ma (early J₂), and then became more and more intensive towards the end of early Cretaceous. The small-scale early J₂ magmatism is the incipience to long-term and large-scale magmatism in this region. A near east-west (EW) trend volcanic belt was distributed across south Hunan, south Jiangxi and southwest Fujian was formed during early J₂ time. Along this belt from the inland toward the coast, the lithology of basalts changes from alkali into tholeiite, and the amount of erupted volcanic rocks and the proportions of rhyolites coexisting with the basalts increase. On the basis of geochemical characteristics of these basalts, we infer that the melting degree of source rocks and the extent of fractional crystallization and crustal contamination all increased whereas the depth of mantle source decreased from the inland to the coast, which led to the variations of geological characteristics of the volcanic belt. In early J₂, the western spreading Pacific plate began to subduct underneath SE China continental block, reactivating near EW trend deep fault that was originally formed during the Indosinian event. The stress of the western spreading Pacific plate and the extent of asthenosphere upwelling increased from the inland to the coast, which is consistent with the generation and evolution of early J₂ basalts.  相似文献