Zircon U-Pb age, geochemical, and Sr-Nd-Pb isotopic constraints on the origin of alkaline intrusions in eastern Shandong Province, China     

Shen Liu  Caixia Feng  Ruizhong Hu  Shan Gao  Tao Wang  Guangying Feng  Youqiang Qi  Ian M. Coulson  Shaocong Lai 《Mineralogy and Petrology》2013,107(4):591-608

Alkaline intrusions in the eastern Shandong Province consist of quartz monzonite and granite. U-Pb zircon ages, geochemical data, and Sr-Nd-Pb isotopic data for these rocks are reported in the present paper. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) U-Pb zircon analyses yielded consistent ages ranging from 114.3?±?0.3 to 122.3?±?0.4 Ma for six samples of the felsic rocks. The felsic rocks are characterised by a wide range of chemical compositions (SiO₂?=?55.14–77.63 wt. %, MgO?=?0.09–4.64 wt. %, Fe₂O₃?=?0.56–7.6 wt. %, CaO?=?0.40–5.2 wt. %), light rare earth elements (LREEs) and large ion lithophile elements (LILEs) (i.e., Rb, Pb, U) enrichment, as well as significant rare earth elements (HREEs) and heavy field strength (HFSEs) (Nb, Ta, P and Ti) depletion, various and high (⁸⁷Sr/⁸⁶Sr) _i ranging from 0.7066 to 0.7087, low ε _Nd (t) values from ?14.1 to ?17.1, high neodymium model ages (T_DM1?=?1.56–2.38Ga, T_DM2?=?2.02–2.25Ga), ²⁰⁶Pb/²⁰⁴Pb?=?17.12–17.16, ²⁰⁷Pb/²⁰⁴Pb?=?15.44–15.51, and ²⁰⁸Pb/²⁰⁴Pb?=?37.55–37.72. The results suggested that these rocks were derived from an enriched crustal source. In addition, the alkaline rocks also evolved as the result of the fractionation of potassium feldspar, plagioclase, +/? ilmenite or rutile and apatite. However, the alkaline rocks were not affected by crustal contamination. Moreover, the generation of the alkaline rocks can be attributed to the structural collapse of the Sulu organic belt due to various processes.  相似文献   

U-Pb Zircon Age,Geochemical, and Sr-Nd-Pb Isotopic Constraints on the Age and Origin of Mafic Dykes from Eastern Shandong Province,Eastern China   总被引：1，自引：0，他引：1  

LIU Shen  HU Ruizhong  FENG Caixi  GAO Shan  FENG Guangying  LAI Shaocong  QI Youqiang  Ian M. COULSON  YANG Yuhong  YANG Chaogui  and TANG Liang 《《地质学报》英文版》2013,87(4):1045-1057

U-Pb zircon age, geochemical, and Sr-Nd-Pb isotopic data of mafic dykes from eastern Shandong Province, eastern China is reported herein. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) U-Pb zircon analyses of two samples from the investigated mafic dykes yield consistent ages ranging from 121.9 Ma ± 0.47 Ma to 122.9 Ma ± 0.61 Ma. The mafic dykes are characterized by high (87Sr/86Sr) i ranging from 0.7087 to 0.7089, low εNd(t) values ranging from -16.9 to -17.8, 206Pb/204Pb = 17.15 to 17.17, 207Pb/204Pb = 15.45 to 15.47, and 208Pb/204Pb = 37.59 to 37.68. Results from the current study suggest that the mafic dykes are derived from partial melting of ancient lithospheric mantle that was variably hybridized by melts derived from foundered lower crustal eclogite. The mafic dykes may have been generated through subsequent insignificant crystal fractionation and very minor crustal contamination during magma ascent. Combined with previous studies, the current findings provide new evidence that the intense lithospheric thinning beneath the eastern Shandong Province of eastern China occurred at ~120 Ma, and that this condition was caused by the removal of the lower lithosphere (mantle and lower crust).  相似文献   

黄河内蒙古河段平滩流量与有效输沙流量关系          下载免费PDF全文

申红彬  吴保生  郑珊  李文文 《水科学进展》2013,24(4):477-482

从水沙组合的角度出发,建立了基于水沙二维向量组合的频率统计方法,并在此基础上提出了有效输沙流量的计算方法。根据黄河内蒙古河段巴彦高勒站1954-2006年日水沙资料及汛后平滩流量资料,采用上述有效输沙流量计算方法计算得到了各年有效输沙流量及相应含沙量组合,进而分析了平滩流量与有效输沙流量及有效来沙系数之间的关系。结果表明,巴彦高勒站平滩流量调整分别受到包括当年在内的前期12年来水来沙条件的影响。  相似文献   

宽甸橄榄岩包体微区地球化学特征及其岩石圈地幔演化     

徐荣  刘勇胜  宗克清  邹东雅  邓黎旭  童喜润  胡兆初  高山 《岩石矿物学杂志》2013,32(5):613-636

华北克拉通东部宽甸新生代碱性玄武岩中携带的地幔橄榄岩包体为我们认识该地区岩石圈地幔性质和演化过程提供了约束。根据橄榄石的Mg^#可将宽甸橄榄岩包体分成两类: 第1类为低Mg^#二辉橄榄岩包体(橄榄石Mg^#相对较低: 89.8～90.3),其单斜辉石具有高TiO₂(0.38%～0.57%)、Al₂O₃(4.41%～6.87%)、FeO_T(2.46%～3.73%)、MnO(0.08%～0.11%)含量和低Cr^#(7.42～14.2)的特征,它们所经历的部分熔融程度较低,这些特征类似于中国东部晚白垩世和新生代玄武岩中低Mg^#橄榄岩,代表了新生饱满的岩石圈地幔;第2类为高Mg^#方辉橄榄岩包体(橄榄石Mg^#相对较高:91.0～92.3),其单斜辉石具有低TiO₂(0.03%～0.33%)、Al₂O₃(2.27%～5.49%)、FeO_T(2.04%～2.40%)、MnO(0.07%～0.08%)含量和高Cr^#(15.3～25.8)的特征,它们经历了较高程度的部分熔融作用,其难熔的地球化学特征完全不同于低Mg^#二辉橄榄岩,却与克拉通内部太古宙和元古宙地幔包体类似,代表了古老难熔岩石圈地幔的残留。两类橄榄岩包体的平衡温度没有显著差异说明宽甸岩石圈地幔不存在明显的分层现象,而是新老岩石圈地幔混杂出现。宽甸橄榄岩包体的微量元素特征表明了它们受到过多期复杂的地幔交代作用,交代介质类型不仅有硅酸盐熔/流体还有碳酸盐熔体,其来源既有太平洋板块俯冲释放的熔/流体,又有因受太平洋板块俯冲扰动而上涌的软流圈熔体,因此太平洋板块俯冲可能对华北克拉通的破坏起到了重要作用。  相似文献   

鲁西南高氟区生活饮用水供水模式研究          下载免费PDF全文

郝奇琛  石建  苏晨  姜山  邵景力  万淼 《水文》2013,33(5):39-45

为有效解决鲁西南高氟区生活饮用水供水安全问题,在水文地质环境地质调查的基础上,通过水质分析、岩土样分析、综合评价研究,查明高氟水的分布规律、圈定生活饮用水找水靶区。结合供水水源空间分布特征、供水现状及供水方式,因地制宜,提出了3种供水模式:以浅层孔隙水或岩溶裂隙水为水源的集中供水模式;以深层孔隙水为饮用水源集中供水并且以浅层孔隙水为生活用水水源的分散供水模式,以及以地表水为主要水源的集中供水模式。供水模式的划分可为鲁西南高氟改水工作及供水安全问题提供技术支持与保障。  相似文献   

内蒙古二道桥地区物化探异常特征及找矿前景分析     

肖明尧  匡应平  姜山 《世界地质》2013,32(4):847-856

以二道桥地区 1∶ 10 000 土壤地球化学测量、高精度磁测、激电中梯等原始数据为基础,综合分析了测区的物化探异常特征、探槽和钻孔原生晕特征,探讨了探槽和钻孔原生晕元素比值特点,推测了矿体产状和大致形态,以及在空间上的成矿部位,预测了 Cu、Pb、Zn、Ag 成矿元素的有利地段,提出了两个找矿重点区域。  相似文献   

基于GPU并行的谱元法地震波数值模拟     

单蕊  朱伟 《中国煤炭地质》2013,25(3)

谱元法是有限元法的一个重要分支,具有对模型适应能力强、计算精度较高和易于实现等优点.有别于有限元的近似计算,谱元法的质量矩阵采用数值积分得到的对角阵,既简化了计算,又可避免计算精度的下降.以用于通用计算领域的GPU为例,介绍了在CUDA编程平台下实现谱元法地震波数值模拟并行化的方法.在实例应用中为避免浮点数据的原子操作,提高计算效率,模型被采样为串行执行的四个并行单元集合体.  相似文献   

Analysis of artificial corner reflector’s radar cross section: a physical optics perspective     

Xin-Jian Shan  Jing-Yuan Yin  Dan-Lin Yu  Cheng-Fan Li  Jun-Juan Zhao  Gui-Fang Zhang 《Arabian Journal of Geosciences》2013,6(8):2755-2765

Among many of the differential interferometric synthetic-aperture radar technologies, artificial corner reflectors (ACR) are widely used in monitoring earthquake deformation and urban subsidence due to their relative stability on synthetic-aperture radar (SAR) acquisition. Apparently, the detection and extraction of ACRs on remotely sensed images would be of utmost importance. Many different geometric types of ACRs are designed to achieve maximum detection. Among them, dihedral, rectangle trihedral, and pyramidal ACRs are the most commonly employed. The cost and difficulty of deploying ACRs in the field, however, render comparison among the three types rather impractical, if not impossible. The current study attempts to tackle the issue from a physical optics perspective. Adopting radar cross section (RCS) as the measure of ACRs’ detectability, we examined the relationships between the ACRs’ RCS under vertical polarity with various parameters including the radar incident angles, width and heights of the ACRs and the azimuthal angles. The analyses indicate that under vertical polarity, among the three types of ACRs, the rectangle trihedral ACR is the most tolerant to its deploying surroundings. To verify the physical optics analysis results, we collected ENVISAT data from a variety of deployed ACRs in the Yan-Huai Basin, China, and derived their reflectance characteristics. The field data agree with the theoretical analyses. From this practice, it seems that the physical optics method might prove to be a rather economical and effective approach to design and select appropriate ACRs in field deployment.  相似文献   

安徽省沙坪沟钼矿床蚀变及其分带特征   总被引：1，自引：0，他引：1  

阳珊  姜章平  张青  陈寿椅  袁小玲  张鹏 《安徽地质》2013,(2):98-103

沙坪沟钼矿床蚀变类型有硅化、钠化、钾化、云英岩化、绢英岩化、黄铁绢英岩化、硬石膏化、萤石化等,与成矿有关的主要蚀变为硅化、钠化、云英岩化,黄铁绢英岩化发生在钼成矿之后;由下到上,由高温到低温将蚀变划分为三个带,即钾化、钠化、云英岩化综合带、绢英岩化带、黄铁绢英岩化带;工业矿体主要分布在钾化、钠化、云英岩化综合带中,绢英岩化带主要构成矿体顶板及分布部分低品位矿体,黄铁绢英岩化带主要分布于基本无矿体的地表及地下浅部。  相似文献   

氟苯尼考在三疣梭子蟹(Portunus trituberculatus)疾病模型内的代谢动力学     

赵青松  金珊  陈寅儿  秦方锦  王锡波  王国良 《海洋与湖沼》2014,45(3):568-573

为了解健康和疾病条件下药物在三疣梭子蟹(Portunus trituberculatus)体内的代谢差异,在构建三疣梭子蟹溶藻弧菌疾病模型的基础上,按25mg/kg剂量分别给健康和患病三疣梭子蟹单次口灌氟苯尼考后,采用高效液相色谱法测定了其肝胰腺、肌肉和血浆中的药物浓度,药时数据应用3P97药代动力学软件拟合。结果显示:氟苯尼考在健康和患病条件下三疣梭子蟹相同组织中的药时曲线形态相似,三种组织的药时数据均符合带时滞的一级吸收二室开放模型;肝胰腺吸收药物最快,肌肉次之,血浆最慢;与健康组相比,患病蟹肝胰腺、肌肉、血浆三种组织对氟苯尼考的吸收和消除速度明显减慢,达峰时间推迟,半衰期延长,清除率减低,最高药物浓度下降,表观分布容积和药时曲线下总面积变大。说明疾病使氟苯尼考在三疣梭子蟹体内的吸收、分布、代谢和消除均发生了显著变化,建议患病三疣梭子蟹口服氟苯尼考的休药期至少10d。  相似文献