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...     

磁县—大名断裂带西段晚更新世以来活动性研究

1830年河北磁县M7^1/2地震发生于磁县—大名断裂带西段, 该断裂地震破裂和活动性的研究受到地震研究者关注。前人研究着眼于1830年磁县大地震的地表破裂, 本文的研究重点是磁县—大名断裂带西段晚更新世以来的断层活动性。应用卫片、 航片解译和野外地震地质调查等方法开展研究, 重要地点进行探槽开挖或野外地质剖面剥落以及采样测年, 确定了断层各段落破裂事件的发生年代。该断裂西段分为3个断层段落: F₂为磁县—峰峰段落, F₃为东田井村—陶泉乡段落, F₄为韩家沟村—甘泉村段落。F₂断层段大部分隐伏, 为早中更新世断层。F₃断层段东端在东田井村南断错距今22 ka地层, 为晚更新世活动断层; F₃断层段在鼓山南山村一带为全新世断层, 从张家楼村到陶泉乡为推测全新世活动断层。F₄断层段为全新世断层。F₄断层段全部位于基岩山区, 可见多处基岩断面、 地震沟槽及断层眉脊等断层破裂; 一些破裂面发育地衣丽石黄衣[Xanthoria elegans (Link.) Th. Fr.], 使用地衣测年方法确定这些破裂面为1830年磁县大地震地表地震遗迹。磁县—大名断裂带终止于F₄西端。综合分析断裂带各个分段的破裂事件, 得到磁县—大名断裂带西段活动事件时空分布, 估计磁县—大名断裂带西段的晚更新世地震复发周期在6000年左右。     

Photometric Survey of Galactic Open Clusters

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CCD Time-Resolved Photometry of Four Newly Discovered CVs

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