内蒙古西乌旗地区二叠纪双峰式火山岩的年代学、地球化学特征和地质意义

为了加深对中亚造山带东段晚古生代构造背景的认识, 选取内蒙古西乌旗地区二叠纪火山岩进行年代学和地球化学研究。分别利用X光荧光光谱(XRF)、SHRIMP锆石U-Pb测年、ICP-MS和ISOPROBE-T方法测定研究区火山岩的主量元素含量、年龄、微量元素和稀土元素含量及Sr-Nd同位素。结果表明, 这套火山岩的SiO₂含量集中分布在53.54%~54.71%和72.61%~80.81%两个区间, 分别属于玄武安山岩和流纹岩, 构成双峰式火山岩组合。流纹岩SHRIMP锆石U-Pb年龄为279 ± 4.3 Ma, 说明它喷发于早二叠世。玄武安山岩轻稀土略富集而重稀土略亏损, (La/Yb)_N为2.06~2.34, 有轻微的Eu负异常, 富集大离子亲石元素和高场强元素, Nb, Ta和Sr有明显的负异常, 推断其来源于深部非原始地幔, 很大程度上受地壳成分的混染。流纹岩亦略富集轻稀土, 略亏损重稀土, (La/Yb)_N为1.70~3.81, 有很强的Eu负异常, Sr, P和Ti相对强烈亏损, Nb和Ta轻度亏损, K, Zr和Hf相对富集, 具有较高的正ε_Nd(t)值(+3.98~+5.62)和年轻的模式年龄T_DM(490~690 Ma), 具有A型花岗岩的特征, 推断其为新生陆壳来源。综合地球化学特征、区域地质特征和前人研究资料, 这套双峰式火山岩具有板内成因特征, 形成于碰撞后的伸展环境。     

滇西马厂箐埃达克质富碱斑岩特征、成因与成矿意义

滇西马厂箐富碱斑岩是滇西一个重要含矿斑岩体。探讨该斑岩体的岩浆属性,为找矿提供理论依据。通过对岩体岩相学研究及元素地球化学分析,结果表明该斑岩具有富碱高K、Th、La等大离子亲石元素,以及Ta、Nb和部分高场强元素亏损,轻重稀土元素强烈分异的地球化学特征;其w La/w Sm,w La/w Yb,无或极弱的δCe和δEu负异常,MgO,Hf,Th,Ta等元素均指示该岩体具有埃达克岩岩浆的亲合性,但不完全等同于典型埃达克岩。该岩体是增厚下地壳重熔形成的花岗质岩浆与幔源富碱岩浆混合作用的产物,该混合熔体的形成并伴随其结晶成岩过程的含矿地幔流体的交代蚀变是促进马厂箐富碱斑岩成矿的关键因素。     

内蒙古四子王旗地区中二叠世火山岩年代学、地球化学特征及构造意义

对华北克拉通与兴蒙造山带结合部位的内蒙古四子王旗地区出露的一套原定为中?下侏罗统的流纹岩进行岩石学、岩石地球化学、锆石U-Pb同位素年代学和Hf同位素组成研究, 确定其岩石成因及地球动力学意义。新获得的流纹岩和流纹斑岩LA-ICP-MS锆石U-Pb 年龄分别为262±2和261±2 Ma, 表明流纹岩的时代应为中二叠世晚期。四子王旗地区流纹岩多属高钾钙碱性系列和钾玄岩系列岩石, 具有高硅、高碱、富铝以及贫钙、贫镁的特征。稀土元素总量较大, 配分曲线明显右倾, 具有中度到重度Eu负异常, 富集大离子亲石元素Rb, Th和轻稀土元素, 亏损Nb, Ta, Sr和Ba等元素。火山岩的ε_Hf(t)为负值(-25.97~-11.94), 可能主要来源于古老地壳熔融岩浆。该套火山岩具有高硅流纹岩的地球化学特征, 表明岩浆经历过结晶分异过程, 岩浆喷出与深部幔源岩浆的加热有关。结合相关构造判别图解, 判断该套火山岩可能形成于后碰撞伸展阶段。     

云南景谷县民乐火山岩地球化学特征及其意义

目的 探讨云南民乐地区晚三叠世玄武岩和安山岩组合的成因机制.方法 对岩体进行详细的野外地质、岩相学及全岩地球化学分析.结果 该套火山岩具有高K,Th,U,La等大离子亲石元素含量,以及Ta,Nb显著亏损的地球化学特征,其La/Nb,Nb/Th,Ta/Yb,Th/Yb,La/Yb,Ti/Zr和Ti/Y等不活动微量元素比值均指示其形成于活动大陆边缘弧环境.结论 这套陆缘弧中-基性火山岩应该是保山地块与昌都-思茅地块发生碰撞后,在陆内环境形成的的滞后型弧火山岩.     

白银矿田火山岩构造环境的地球化学证据

白银矿田是我国著名的海相火山岩块状硫化物矿床,通常认为该火山岩是大陆裂谷环境的双峰式组合.新的地球化学数据表明,玄武岩属钙碱性系列,富集Th和轻稀土元素(LREE),亏损Ti和高场强元素(HFSE),Th/Nb比值高(0.9～1.3),εNd(T)值低(-1.2～+3.4),源于弱亏损的地幔源区,推测形成在成熟岛弧或具较薄陆壳基底的活动陆缘环境.流纹岩也为钙碱性,贫Ti,Nb,Sr和Yb;Th/Nb比值高(0.8～1.6);εNd(T)值高(＞4);形成在洋内岛弧环境.玄武岩和流纹岩具有不同的地球化学性质、形成环境和时代,因此,不具备双峰式组合特征.     

大兴安岭柴河白音高老组流纹岩锆石U-Pb定年及成因探讨

为了研究大兴安岭中段柴河地区白音高老组流纹岩的形成时代和岩石成因,进行了锆石U-Pb同位素年龄测试和地球化学研究.LA-ICP-MS锆石U-Pb定年结果显示,白音高老组流纹岩形成于年龄为129~137 Ma的早白垩世.岩石地球化学研究表明,白音高老组流纹岩具有高硅富碱、贫钙镁的特征;稀土丰度总量m(∑REE)=121.35×10-6~194.92×10-6,轻重稀土分馏明显,m(La)/m(Yb)N=12.2~21.7,Eu负异常(δ_(Eu)=0.39~0.61),微量元素以富集Rb,Ba,Th,K,亏损Nb,Sr,P,Ti为特征;白音高老组流纹岩原始岩浆来源于上地壳岩石的部分熔融.     

山东邹平王家庄铜矿含矿岩体地球化学及成因探讨

王家庄铜矿床是山东省重要的铜金属产地之一．在野外地质工作基础上,通过岩石化学和同位素地球化学等方法,详细研究了与王家庄铜金矿床有关的石英二长岩,研究表明含矿岩体具有偏碱性,富钠和准铝质的特征;Rb、Ba、Sr等大离子亲石元素（LILE）和Th、U富集,Nb、Ta、Ti等高场强元素（HFSE）亏损;轻重稀土分异明显（La／Yb）N=23．09～29．93,未见Eu异常（8Eu=0．85～1．05）．全岩^205Pb／^204Pb介于18．5826～18．6675之间,均值为18．6197;^207Pb／^204Pb介于15．5850～15．6077之间,均值为15．5931^207Pb／^204Pb介于38．5749～38．6109之间,均值为38．5980;全岩δ^18O值变化于8．23‰～10．90‰之间,均值为9．40‰;铅、氧同位素组成表明成岩物质来自地壳深部或地幔,岩浆在上升过程中可能受到富^18O地壳物质的混染,具富放射性成因铅的特征（^207Pb／^204Pb〉18．00）．     

甘肃北山中带早泥盆世的构造-岩浆作用:来自公婆泉花岗岩体年代学和地球化学证据

为加深对北山地区古生代构造演化的认识,选取甘肃省北山公婆泉花岗岩体进行年代学和地球化学研究。公婆泉花岗岩体位于北山中带,明水–小黄山蛇绿岩带与红柳河–牛圈子–洗肠井蛇绿岩带之间。根据花岗岩矿物组成及地球化学特征将其分为两种不同类型:1)淡色花岗岩含石榴石、原生白云母和电气石等特征矿物,轻、重稀土元素分异不明显,(La/Yb)N=1.38~1.93,有明显的Eu负异常(δEu=0.19~0.28),同时富集Cs,Rb,Th,U,K,P和Hf,亏损Ba,Nb,Nd和Ti;2)二长花岗岩具有过铝质S型花岗岩的特征,A/CNK值平均大于1.1,轻、重稀土元素分异不明显,(La/Yb)N=2.74~22.78,具轻微的Eu异常(δEu=0.83~1.07),同时富集Cs,Rb,Ba,Th,U和K,亏损Nb,Ta,P和Ti。公婆泉两类花岗岩的矿物学和地球化学特征表明其形成于后碰撞环境。公婆泉花岗岩体的锆石LA-ICP MS U-Pb年龄为402.2±3.0 Ma,代表其岩浆结晶年龄,εHf(t)值介于0.1~2.9之间,暗示幔源物质的加入。公婆泉后碰撞花岗岩体与北山造山带西段相关花岗岩类的地球化学和年代学特征证实,北山中带的俯冲过程于早泥盆世之前在西段结束,并且此时在区域上处于后碰撞环境。     

水汶盆地碎斑熔岩LA-ICP-MS锆石U-Pb年龄及地球化学特征

广西水汶火山盆地西垌组四段碎斑熔岩锆石LA-ICP-MS U-Pb测年结果显示其形成年龄为(83.4±0.9)Ma,属晚白垩世火山-岩浆活动的产物.碎斑熔岩富SiO2(73.57％～ 74.29％),富K2O(4.91％～ 5.61％),低P2O5 (0.03％～0.04％),准铝-弱过铝质(A/NKC为0.99 ～ 1.03),富集Rb,Th以及La,Ce,Nd等轻稀土元素,亏损Ba,Nb,Ta,Sr,P,Ti,Rb/Sr比值高(1.16～ 1.73),Y和Th含量与Rb含量之间具有正的相关性,过碱指数(AI值),Zr+Nb+Ce+Y值、FeO*/MgO值、10000×Ga/A1值均小于典型的A型花岗岩,与高分异Ⅰ型花岗岩地球化学特征十分相似,应该是太平洋板块俯冲作用背景下,形成于弧后拉张构造环境的高分异Ⅰ型碎斑熔岩.     

鄂尔多斯盆地延长组钾质斑脱岩地球化学特征

鄂尔多斯盆地延长组长7油页岩中夹有多层钾质斑脱岩,为研究其地球化学特征,通过野外露头、岩心观察、X射线衍射分析、X荧光光谱分析、ICP-MS分析等手段,对长7钾质斑脱岩进行了细致的地球化学分析。结果表明:该斑脱岩以黏土矿物为主,其次为石英和长石;Si O2质量分数平均为61%,其次是Al2O3和K2O,分别为22.24%和3.7%,显示经历了强烈的蚀变作用;与北美页岩相比,Cr、Ni含量明显亏损,Rb、Sr、Th、U等含量明显偏高;与球粒陨石相比,Rb、Th、La偏高,Nb、Sr、Y相对较亏损;∑REE在(147.57~203.13)×10-6之间,稀土元素配分模式为"右倾型",即轻稀土富集、重稀土亏损,Eu负异常;在Nb/Y-Zr/Ti O2图解中,数据点主要落在流纹岩—流纹英安岩之间,表明火山物质主体来源于中酸性岩。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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