Transition-Zone Mineral Assemblages in Peridotite Massifs, Tibet: Implications for Collision-zone Dynamics and Orogenic Peridotites

<正>Diamonds have been reported from Tibetan"ophiolites"for≥30 years,but have been widely dismissed as contaminants,because their unusual morphology and light C(δ~(13)C=-18 to–27)are unlike those of kimberlitic diamonds.However,the diamonds have now been found in situ in both the chromitites and the peridotites of     

Diamonds and Highly Reduced Minerals from Chromitite of the Ray-Iz Ophiolite of the Polar Urals: Deep Origin of Podiform Chromitites and Ophiolitic Diamonds

<正>The Uralide orogenic belt is a major early Paleozoic suture zone extending more than 3000 km in a N-S direction,and geographically divides Europe from Asia(Chemenda et al.,1997).Ophiolites,podiform chromitites and high pressure metamorphic rocks are well developed in the orogenic belt(Leech and Ernst,2000).The Ray-Iz     

Our Petroleum Prospect

As a result of the wide industrial development as well as extensive construction of the public highways and the consequent demand of motor-car gasoline,the petroleum consumption in China is becoming greater and greater every year.According to the recent report of the Customs office, the import of gasoline,kerosine, fuel oil and lubricating oil has reached in 1933 a total of about eightmillion barrels, valued at 140 million Shanghai dollors.     

Jack Hills锆石的安山质源区支持板块构造始于冥古代北大核心CSCD

地球最老的地壳组成和构造属性是地球科学研究中两个最基本的问题,但是由于缺乏合适年龄的岩石,难以进行约束。很多研究主要集中于西澳Jack Hills变质沉积岩中4.4~4.3 Ga的碎屑锆石,但是对其原岩性质的认识依然缺乏共识。对其原岩成分的推断主要基于锆石的Hf同位素组成,研究者普遍认为这些碎屑锆石来源于火成岩源区。     

Smart Sediment Particle: A novel approach to investigating fluvial bed entrainment using instrumented sensors

The Smart Sediment Particle(SSP) instrumented with multiple sensors to obtain tri-axial linear accelerations is used for studying the mechanism of coarse grain entrainment. Three bed arrangements are tested to examine their influences on entrainment processes and the threshold force and impulse conditions. The SSP shows satisfactory precision to capture the imperceptible movement tendencies immediately(e.g., 0.15 s) after the dislodgement. The experimental results show that bed packing can signi...     

Photometric Survey of Galactic Open Clusters

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CCD Time-Resolved Photometry of Four Newly Discovered CVs

1　ＩｎｔｒｏｄｕｃｔｉｏｎＩｎｏｕｒｓｐｅｃｔｒｏｓｃｏｐｉｃｏｂｓｅｒｖａｔｉｏｎｏｆｔｈｅｏｐｔｉｃａｌｉｄｅｎｔｉｆｉｃａｔｉｏｎｏｆＲＯＳＡＴＸ ｒａｙｓｏｕｒｃｅｓｉｎｔｈｅｈｉｇｈｇａｌａｃｔｉｃｌａｔｉｔｕｄｅ ,8ｎｅｗｃａｔａｃｌｙｓｍｉｃｖａｒｉａｂｌｅｓｗｅｒｅｄｉｓｃｏｖｅｒｅｄｂａｓｅｄｏｎｔｈｅｉｒｓｐｅｃｔｒａｌｎａｔｕｒｅ.ＰｒｅｌｉｍｉｎａｒｙｄｉｓｃｕｓｓｈａｄｂｅｅｎｒｅｐｏｒｔｅｄｂｙＨｕｅｔａｌ ( 1 998) .ＷｅｈａｖｅｍａｄｅＣＣＤｔｉｍｅ ｒｅｓｏｌｖｅｄｐ…     

日本中部伊豆半岛东部地震的震磁模型

4次破坏性地震所伴随的震磁变化用压磁效应作了解释,这些变化是在日本中部伊豆半岛东部观察到的。大部分数据由重复测量获得。虽然这些数据受到电力火车噪音的影响,但在靠近地震断裂的测点上观测到了有意义的地磁变化。1978年伊豆半岛附近地震(M7.0)与1980年伊豆半岛东部近海地震(M6.7)的同震变化都可由压磁模型得到很好的解释。在靠近1976年河津地震(M5.4)震中的一个测点上观测到高达5nT的总强度变化。该变化不能由单断裂模型解释,由此提出了一个双断裂模型。对于1978年东伊豆地震(M4.9),在KWZ台观察到显著前兆性的与同震的总强度变化。KWZ台很靠近伊豆大岛附近地震(M7.0)的隐伏分支断裂,M7.0地震发生时此断裂存在无震移动。M4.9地震的前兆磁变化被描述为是这条隐伏断层的无震断裂。而M4.9地震的同震回弹扩大了断层滑动面。这意味着我们通过磁场观察到了地震成核带的形成过程。