Origin of C type adakite magmas in the NE Xing’an block,NE China and tectonic implication

In this paper, we report new whole-rock geochemical and zircon U–Pb data for monzogranites in the NE Xing’an block. These data constrained the petrogenesis of C type (high Sr/Y) adakitic rocks and showed the spatial extent of the influence of the Mongol-Okhostsk ocean tectonic regime and the collision between the Jiamusi Massif and Songliao Terrane. New zircon laser-ablation inductivity coupled plasma mass spectrometry (LA-ICP-MS) U–Pb data indicated that the monzogranites in the studied area were emplaced in the Early Jurassic (~180 Ma). These rocks were characterized by unusally high SiO₂ (≥67.49), and Sr (461–759 ppm), but strikingly low Y (4.63–8.06 ppm) and HREE (∑HREE = 3.83–6.49 ppm, Yb = 0.5–0.77 ppm) contents, with therefore high Sr/Y (67.2–119) and (La/Yb)_N (29.7–41.5) ratios, showing the geochemical characteristics of C type adakitic granite. The data displayed negligible Eu anomalies (Eu/Eu* = 0.77–1.08), LREE-enriched and pronounced negative Nb and Ta anomalies. The C-type adakites in the studied area were most likely derived from the partial melting of a thickened lower continental curst. The magma source is most likely dominated by amphibolites and garnet amphibolites. In combination with previously-reported data from igneous rocks from the Mesozoic in NE China, we conclude that the Xing’an block was influenced by the Mongol-Okhotsk subduction tectonic system, and experiences compressive settings from the amalgamation of the Jiamusi block in the east of the CAOB.     

Occurrence and levels of polybrominated diphenyl ethers (PBDEs) in recent sediments and marine organisms from Xiamen offshore areas, China

Surface sediments and porewater from 12 sites within Xiamen offshore areas and organisms from a heavily contaminated site Yuandang Lagoon were sampled and analyzed for eight polybrominated diphenyl ethers (PBDEs) congeners (-28, -47, -99, -100, -153, -154, -183 and -209). The total concentrations of eight PBDEs (∑₈PBDEs) and BDE-209 in sediments ranged from 0.27 to 76.54 ng/g with an average of 16.31 ng/g and from 0.10 to 70.11 ng/g with an average of 14.94 ng/g, respectively. Concentrations of ∑₈PBDEs in porewater ranged from 2.5 to 34.1 ng/L, with a mean value of 15.3 ng/L. In this study, the partition coefficients (log ) of PBDE congeners (without -209) were significantly correlated with their octanol-water partition coefficients (log K_OW) (r² = 0.74, P < 0.01). ∑₈PBDE concentrations ranged from 0.33 to 1.26 ng/g (lipid weight) in marine organisms, and PBDE congener patterns were significantly different between fish and clam, crab.     

Incorporation of in situ exposure and biomarkers response in clams Ruditapes philippinarum for assessment of metal pollution in coastal areas from the Maluan Bay of China

The clams Ruditapes philippinarum were used to assess the impact of metal contaminants when transplanted to seven study sites along the Maluan Bay (China). Metal concentrations in digestive gland tissues of clams after 7-day in situ cage exposure were determined in conjunction with antioxidant enzyme activities. The results showed the importance of specific antioxidant biomarkers to assess complex pollutant mixtures and their good correlations to the pollutant compositions of deployment sites. Multivariate analysis indicated causal relationship between the chemicals at each study site and the biochemical "response" of the caged clams at these sites and demonstrated the potential presence of two different contaminant sources. This study suggested that the incorporation of tissue residue analysis with biomarkers response in caged clams together with factor analysis can be a useful biomonitoring tool for the identification of causal toxic pollutants and the assessment of complex metal pollutions in marine coastal environment.     

大兴安岭中段碾子山地区晚三叠世埃达克质侵入岩的发现及其地质意义

为加深对大兴安岭中段早中生代构造背景的认识,选取碾子山地区早中生代花岗岩开展岩石学、年代学和元素地球化学研究.结果表明,该地区早中生代花岗岩岩石组合为正长花岗岩和石英二长岩,其LA-ICP-MS锆石U-Pb年龄为225.6～228.9 Ma,形成于晚三叠世.二者的地球化学特征与埃达克岩的地球化学特征非常类似,如高Al2...     

江苏省旅游经济重心演进格局及其驱动机制

运用重心模型,定量分析了2001—2012年江苏省旅游经济时空格局的演进过程。江苏省旅游外汇收入重心持续北上,国内旅游收入重心则先南下、后北上,旅游总收入重心的演化路径与国内旅游收入较为相似;江苏省旅游外汇收入重心、国内旅游收入重心和旅游总收入重心都明显偏离几何中心,但呈缓慢趋同态势;旅游外汇收入重心与入境旅游客流重心、国内旅游收入重心与国内旅游客流重心、旅游总收入重心与旅游客流总量重心均呈现出显著的空间分离特征。从资源开发、政策支持、经济基础、对外开放和事件影响等方面深入剖析了江苏省旅游经济重心移动的驱动机制。旅游资源的开发利用是旅游经济重心移动的关键驱动因素,政府的区域发展政策是旅游经济重心移动的直接驱动因素,经济发展的区域格局及其变化促进旅游经济重心的移动,对外开放的全面推进成为旅游经济重心移动的助推剂,重大事件驱动旅游经济重心变化趋势发生短暂性偏离。     

黑龙江依兰地区变玄武岩及变堆晶辉长岩LA-ICP-MS锆石U-Pb年龄及其地质意义

对依兰地区黑龙江混杂岩中的变玄武岩、变枕状玄武岩及变堆晶辉长岩岩块中的锆石进行了LA-ICP-MS U-Pb同位素测定,结果表明,变玄武岩的锆石大量为捕获基底的锆石,其年龄范围大,从3172±24Ma到176±1Ma均有分布,其中具有基性岩典型的板状特征的锆石年龄为243±1Ma,代表了变玄武岩的原岩形成年龄;变枕状玄武岩及变堆晶辉长岩的年龄分别为251±1Ma和252±1Ma,分别代表各自原岩的形成年龄。本次锆石年龄的获得,证明晚二叠世佳木斯地块和松嫩-张广才岭地块之间存在古洋盆,为研究黑龙江杂岩的演化历史提供了重要的年代学依据。     

用改进的相对幅值法反演震源机制及其在核爆炸地震事件识别中的应用

与波形反演方法相比,相对幅值法在利用短周期地震波反演震源机制时不需要高分辨率的地球模型,因此更适合于低震级地震事件的震源机制反演．本文以Pearce的传统相对幅值法为基础,引入一种新目标函数以量化特定震源机制解模型的直达P波与地表反射pP和sP波的理论相对幅值与实际观测之间的不吻合程度,由此提高了相对幅值法的容错能力．利用改进的相对幅值法,反演了吉尔吉斯斯坦伊赛克湖地区震级分别为mb4.9和mb3.8的两次天然地震震源断层面解．对于较大的地震,利用5个远震台阵上观测的pP/P和sP/P相对幅值得到的震源断层面解,与哈佛大学的CMT断层面解非常接近;对于哈佛大学没有给出CMT解的较小地震,利用同样方法得到的震源断层面解的走向与震中位置处主要断层的走向一致,而且利用该断层面解可以拟合和解释区域台站上的长周期波形和P波初动方向．最后,为了说明相对幅值法在地下核爆炸地震事件识别中的应用,利用改进的相对幅值法分析了朝鲜2006年10月9日核试验的远震P波波形,发现没有断层面解与远震台站上的P波波形特征相吻合．      

太湖北岸湖滨带观测场水生植物群落特征及其影响因素分析

研究了鄱阳湖流域在1955-2002年间的径流系数的变化,重点分析了它与水循环的两个基本要素:降水量和蒸发量的关系,同时对其原因进行了初步的探讨.经分析,在鄱阳湖流域中,径流系数较大的是饶河流域和信江流域,较小的是抚河流域;在年内变化上,4-6月为五河流域径流系数比较大的月份,这与鄱阳湖流域降水集中期相对应.在空间上,4-6月仍然以饶河流域和信江流域相对较大,而抚河流域较小,特别是8月份的径流系数远小于其他四河;年代际变化上,1990s径流系数增加较为显著.尽管鄱阳湖流域的径流系数除了受气候因子的影响外,还受到水土流失和地形等因素的影响,但是降水量的增加,特别是暴雨频率的增加仍然是其主要影响因素,蒸发量的减小对径流系数的增加也有一定程度的影响.径流系数与气温并无明显的线性相关关系.     

基于贝叶斯原理的爆炸识别判据综合技术研究

基于贝叶斯原理,建立了地震事件识别判据的综合方法（简称贝叶斯方法）, 并针对中亚地区大量地震事件,采用该方法综合了不同台站和不同频带的P/S震相幅值比判据. 该方法的主要优点是能够给出事件属于爆炸的概率,而且充分考虑了判据之间的相关性. 理论计算和模拟数据分析结果表明, 贝叶斯方法是最优的综合方法, 其识别效果比任何单个判据好,也好于普通线性组合方法的识别效果. 针对中亚地区大量地震事件综合不同台站和不同频带的P/S震相幅值比判据的结果也表明,贝叶斯方法的误识率低于单个判据和线性组合方法的误识率.      

某沥青铀矿石堆浸性能的研究

简要介绍了铀矿床的类型和铀矿石的分选方法,重点介绍了某火山岩型铀矿床硬岩类原生沥青铀矿石的实验室溶浸试验。试验结果表明,该沥青铀矿石在用天然铁锰矿石为氧化剂的条件下,经过123d实验室溶浸试验,铀浸出率可达78.92%。