西藏高原沱沱河盆地渐新世-中新世湖相碳酸盐岩稀土元素地球化学特征与正铕异常成因初探

对采自沱沱河盆地通天河剖面渐新世雅西措群和中新世五道梁群地层中的湖相灰岩和白云岩样品进行了稀土元素和微量元素分析。研究结果表明,湖相碳酸盐岩稀土元素总量（∑REE）变化于36.23×10-6～189.64×10-6,28件样品平均值为78.58×10-6。稀土元素的页岩标准化配分形式具有中组稀土富集的特点,正铕异常极为明显,在渐新统与中新统界线处Eu/Eu*比达到最大值7.15,这也是首次在陆地湖泊沉积记录中观察到的正Eu异常。根据稀土元素的分布以及Eu与Ba含量的同步变化特点,提出该区湖相碳酸盐岩中Eu的异常富集可能与湖底喷流热水有关。      

2013年芦山7.0级地震前重力固体潮参数时空变化研究

以2013年芦山7.0级地震为例,探讨重力固体潮参数的时空分布特征与地震孕育的关系。收集分析芦山震区附近17个台站震前2 a的连续重力观测数据,采用VAV调和分析方法分析计算日波和半日波潮汐参数,主要研究半日波M 2波潮汐因子随时间变化的趋势及空间分布情况。结果表明,芦山地震前M 2波潮汐因子趋势变化空间分布大体呈现上升与下降趋势的四象限分布,芦山地震处于四象限中心部位,可能是由震前存在的“闭锁剪力”引起的区域介质变形或密度扰动所致。     

钻孔应变观测原位标定方法研究进展

钻孔应变观测的原位标定是制约钻孔应变定量观测理论与技术发展的基础性问题。为推进钻孔应变观测在地球动力学研究中的应用,从标定模型、参考应变信号等方面系统总结钻孔应变观测原位标定方法研究的最新进展,指出钻孔应变观测原位标定中存在的主要问题,并展望今后的发展方向。     

Ten-year progress of Chinese polar geodesy: 1996–2006

The ten-year progress of Chinese polar geodesy from 1996 to 2006 is summarized. Research on plate motion, crustal movement, orbit determination, and atmospheric monitoring, including the ionosphere and troposphere, were performed using GPS data of the Great Wall Station, Zhongshan Station and Yellow River Station. GPS was also applied in the Amery Ice Shelf, Grove Mountains and Dome A expeditions to study ice dynamics. During the 2004/2005 austral summer season, the absolute gravity and relative gravity were measured at the Great Wall Station with precision within ± 3 × 10⁻⁸ ms⁻² and ± 10 × 10⁻⁸ ms⁻² respectively. The tide gauge, which was set up in Zhongshan Station to monitor sea level change in 2000, recorded the 2004 Indian Ocean tsunami. SAR interferometry was applied to build the DEM of ice sheet and monitor ice flow in the polar region. __________ Translated from Advances in Earth Science, 2007, 22(8): 784–790 [译自: 地球科学进展]     

Rare Earth Magnets: Conservation of Energy and the Environment

Rare earth sintered magnets (Nd magnet) have been used in many applications such as computer and industrial equipment, automobile manufacturing and many others. They are highly efficient and reduce energy consumption because of their superior magnetic properties. The element dysprosium (Dy) contained in the Nd magnet is important and indispensable. It improves the stability of the Nd magnet by enhancing the coercive force of its magnetic properties at high temperature. Dy is not so abundant. The rapid growth of the Nd magnet may result in Dy shortage. Exploration for new deposits of Dy is desired.     

Geochemistry of rare earth elements in a marine influenced coal and its organic solvent extracts from the Antaibao mining district, Shanxi, China

Twenty-six samples including roof, bottom and coal plies of a marine influenced coal bed were collected from the Antaibao mining district, Shanxi, China. The rare earth elements (REEs) were determined in solids and organic solvent extracts. The distribution pattern showed three distinct patterns: shale-like, LREE-rich and HREE-rich. This is attributed to the variable microenvironment of peat-forming swamp, the degree of marine influences and different REE sources. REEs in the coal are mainly controlled by detrital minerals but also affected by seawater. The chondrite-normalized REE patterns of the organic solvent extracts are distinctly different from those of corresponding original coal samples, which show a negative Eu anomaly, a depletion of middle REEs and an enrichment of HREEs. The LREEs in coal extracts are likely adsorbed by hydrogen-containing functional groups, and HREEs are likely bonded to carbon atoms.     

甘肃南梁—华池地区三叠系延长组长三段储层物源探讨

利用稀土元素和微量元素,分析鄂尔多斯盆地南部南梁—华池地区上三叠统延长组长三段储层母岩类型和物源方向,研究表明盆地南部南梁—华池地区延长组砂岩和泥岩的稀土元素地球化学特征、REE分配模式及微量元素蜘蛛图解相同,与盆地东北缘太古代、元古代变质岩相似,但不相同;与盆地西南缘的水河地区延长组相似且不同,说明研究区与盆地东北缘和西南缘均有较好的亲缘关系。结合轻、重矿物组合和盆地周缘古陆岩矿特征,证实了研究区物源为两个主物源的混合区。     

贵州遵义牛蹄塘组黑色岩系有机质的稀土元素地球化学研究

以贵州遵义寒武纪初牛蹄塘组黑色岩系的有机质为分析对象,对22个样品的稀土元素(REE)组成进行了研究,结果表明:①有机质的∑REE占全岩∑REE的lO%左右,且其REE标准化配分曲线不同于全岩的.由于有机质主要来自海洋上层水体中的微生物,囚而可以认为其REE特征代表的是古海洋上层水体的稀土元素组成特征;②有机质的REE总量变化于11.6×10-6～548×10-6之间,Ce异常系数变化于O.40～O.92之间,Eu异常系数变化于O.59～1.14之间.有机质的ce异常系数和LaN/CeN值在剖面上显示明显的变化,指示研究区经历了大陆斜坡到大洋盆地再到大陆边缘的环境,指示在寒武纪初存在一次海侵.     

Geochemical behavior of rare earth elements in hydrothermally altered rocks of the Kuroko mining area,Japan

In this study we analyzed the chemical composition of hydrothermally altered dacite and basalt from the Kuroko mining area, northeastern Honshu, Japan, by REE (rare earth element). Features of rare earth element analyses include: (1) altered footwall dacite exhibits a negative Eu anomaly compared with fresh dacite, suggesting preferential removal of Eu²⁺ from the altered dacite via hydrothermal solutions, (2) altered hangingwall dacite and basalt and dacite and basalt adjacent to ore deposits exhibit positive Eu anomalies compared with fresh dacite and basalt, suggesting addition of Eu²⁺ from hydrothermal solutions, (3) LREE ratio (∑LREE/∑REE) from altered dacite of chlorite–sericite zone and K-feldspar zone show a negative relationship with δ¹⁸O, and La/Sm ratios show a positive correlation with the K₂O index. These trends indicate the addition of light rare earth elements such as La to the altered dacite from hydrothermal solution and/or leaching of heavy rare earth elements such as Sm and Yb, (4) Principal component analysis (PCA) indicates that light rare earth elements enrichment is related to the formation of sericite zone near the Kuroko deposits but not to the formations of chlorite and K-feldspar zones, and (5) The correlations among REE features (LREE ratio, MREE ratio, HREE ratio, Eu/Eu?), δ¹⁸O and K₂O index are not found for montmorillonite zone, mixed layer clay mineral zone and mordenite zone. Therefore, it is inferred that sericite, chlorite and K-feldspar alterations are related to the Kuroko and vein-type mineralization, but montmorillonite and mordenite alterations are not related to the mineralizations, and probably they formed at the post-mineralization stage.     

Heavy metals and rare earth elements (REEs) in soil from the Nam Co Basin,Tibetan Plateau

Twenty-eight soil samples collected from the Nam Co Basin, Tibetan Plateau, have been analyzed for heavy metals (Cd, Cr, Ni, Cu, Zn, Pb and Mn), arsenic (As) and rare earth elements (REEs). In addition, for establishing the basic physio-chemical characteristics of the soil, pH, total organic concentration, electrical conductivity, and effective cation exchange capacity were measured. The results indicate that soil in the Nam Co Basin is still at an early alkaline weathering stage (pH = 7.94). Mean concentrations of heavy metals and As decreased as follows: Mn > Cr > Zn > Pb > Ni > Cu > As > Cd. The values of Cd, Cr, As, Pb and REEs in soil from the Nam Co Basin are higher relative to averaged background values over China. The chondrite-normalized diagrams of REEs suggest high REE(ΣLa → Eu)—enrichment, HREE(ΣGd → Lu)—depletion and Eu—depletion. Vertical profiles indicate that both heavy metals (except As) and REEs primarily exist in the surface soil. However, heavy metals and REEs vary in the surface soil between the southern and the northern bank of Nam Co. These differences are controlled mainly by parent materials.