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1.
在江西省朱溪矿集区张家坞地区发现了黄铜矿化花岗闪长斑岩,岩石中w(SiO_2)为66.60%~66.84%,w(Al_2O_3)为15.64%~16.70%,w(K_2O+Na_2O)为8.76%~9.60%,表明其为过铝质花岗闪长岩类;∑REE为(85.55~101.77)×10~(-6),轻重稀土元素分馏明显,(La/Yb)_N值为9.86~16.72,具Eu负异常;富集Rb、Th、U、K等大离子亲石元素,亏损Ta、Nb、P、Ti等元素,w(Sr)为(382.9~529.4)×10~(-6),w(Y)为(7.32~14.33)×10~(-6),w(Yb)为(0.54~1.04)×10~(-6),具有埃达克(质)岩的特征。根据岩石微量元素数据及相关图解分析结果,文章认为由于受岩石圈伸展作用的影响,软流圈上涌,对下地壳产生底劈作用,为下地壳岩石的熔融提供热量使下地壳发生部分熔融,从而导致岩石圈减薄,张家坞花岗闪长斑岩岩浆来源于加厚下地壳部分熔融。研究结果表明,张家坞花岗闪长斑岩具有岩石圈伸展构造背景,基底地层具有较高Cu元素丰度值,发育众多导矿构造,相比于华南地区成矿花岗岩,塔前—大游山地区具有良好的斑岩型铜矿成矿潜力。  相似文献   

2.
选取西秦岭夏河-合作断裂以南广泛发育的中酸性脉岩进行岩石学、岩石地球化学分析研究:研究区脉岩具有低硅低镁(SiO_2占55.14%~68.42%,平均64.13%;MgO占0.101%~1.02%,平均0.633%);高钠低钾(Na_2O/K_2O=0.63~2.920.5);高铝高钛(Al_2O_3含量大于15%;TiO_2占0.462%~0.806%,平均0.566%)特征。轻稀土元素(LREE)富集(LREE为195.89×10~(-6)~223.95×10~(-6),平均215.85×10~(-6)),重稀土元素(HREE)严重亏损(HREE为10.45×10~(-6)~14.56×10~(-6),平均11.86×10~(-6)),轻重稀土元素分馏明显,具弱的负铕异常(δ_(Eu))(δ_(Eu)=0.61~0.97,平均0.75);微量元素组成与埃达克岩类似,高Sr、低Y,高场强元素Th、U、Zr、Hf正异常,大离子亲石元素K、Ba、Sr负异常。脉岩具有奥长花岗岩-英云闪长岩-花岗闪长岩(TTG)岩套的性质,脉岩产生于晚三叠世洋壳俯冲消减活动大陆边缘弧环境。脉岩与金矿化是同一构造-岩浆旋回内区域壳幔相互作用的系列产物,金成矿与脉岩不仅在时空上密切伴生,而且物质成分上具有相同的来源和继承演化的成因联系。  相似文献   

3.
对贺兰山北段似斑状花岗岩进行岩相学、岩石地球化学及锆石U-Pb年代学进行研究,探讨其成因机制及其源岩性质。研究结果表明:似斑状花岗岩具有高物质的量比即n(Al_2O_3)/n(Na_2O+K_2O)(记为A/CNK,为1.18~1.29)、低FeOt和MgO质量分数比即w(FeOt)/w(MgO)(小于10)、低P_2O_5(质量分数为0.15%~0.22%)和高K_2O(质量分数为5.09%~5.86%)的地球化学特征,属于典型的强过铝质S型花岗岩。岩石轻稀土富集,轻重稀土分异明显([w(La)/w(Yb)]N=10.4~153.6),具有明显的Eu负异常(δ(Eu)=0.19~0.49);同时,岩体富集大离子亲石元素(LILE)K和Rb,亏损高场强元素(HFSE)Nb,Ta,Zr,Hf和Ti等。似斑状花岗岩与孔兹岩具有相似的微量和稀土元素地球化学特征,推断其应为孔兹岩部分熔融的产物。较低的w(CaO)/w(Na2O)、较高的w(Rb)/w(Sr)和w(Rb)/w(Ba)暗示孔兹岩的原岩应为泥质岩或是以泥质岩为主的、成熟度较高的沉积岩,反映其当时的沉积环境应为被动大陆边缘,而非活动大陆边缘。似斑状花岗岩LA-ICP-MS锆石U-Pb年龄为(1922±31)Ma,与孔兹岩带内所记录的1.92~1.90Ga期间的岩浆-变质事件相吻合,可能反映了构造体制由碰撞挤压到伸展的转变。  相似文献   

4.
博格达山东段北缘分布有早石炭世玄武岩和流纹质火山碎屑岩及少量英安岩夹层,在时空上构成双峰式火山岩组合.玄武岩Rb-Sr等时线年龄为322±3 Ma(1σ-),w(SiO_2)为47.74%~49.34%,Ti的质量分数(w(TiO_2)=1.51%~1.75%)略高于N-MORB的,高Al(w(Al_2O_3)=16.82%~17.54%),富钠贫钾(w(K_2O)/w(Na_2O)=0.21~0.28),低Mg(w(MgO)=3.80%;7.33%,w(Mg~#)=42~47).表明玄武岩浆发生过橄榄石、辉石分离结晶作用.玄武岩具较高的w(Zr)/w(Y)(4.1~5.5),w(Zr)/w(Nb)(27~33),相对富集LIL(Sr,Rb,Ba,K),亏损Nb,Ta,Th,U等高场强元素,以及(w(~(87)Sr)/w(~(86)Sr))_I为0.703188~0.703 295(0.704 5),正εNd(t)值(+7.10).岩石LREE适度富集,(w(La)/w(Yb))N=2.56~3.66,Eu无异常或轻微正异常(δEu=1.08~1.15).地球化学特征表明:研究区玄武岩源于亏损地幔,且在岩浆作用过程中可能发生过下陆壳物质的混染作用,但斜长石分离结晶作用不明显,形成于陆内裂谷环境.  相似文献   

5.
为了研究清水河东沟斑岩型铜钼矿床赋矿岩体英云闪长岩和辉绿玢岩的成因、演化及产出背景,文中通过对该两种岩体的主量元素、微量元素、稀土元素特征和成岩环境进行了分析和探讨。结果表明:英云闪长岩中主量元素SiO_2(64.89%~66.89%)、富Al_2O_3(14.58%~15.84%)、CaO(4.09%~4.88%),属钙碱性过铝质英云闪长岩;稀土含量较高(138.41×10~(-6)~176.21×10~(-6)),轻稀土元素富集,重稀土元素亏损;δEu的变化范围为0.51~0.67,岩石中Ba,Nb,Sr的亏损较明显;结合岩石地球化学图解,认为英云闪长岩形成的环境为火山弧花岗岩环境。辉绿玢岩中主量元素具有低SiO_2(58.43%~58.96%)、富Al_2O_3(16.18%~16.51%)、全碱K_2O+Na_2O(5.15%~5.52%)的特征,属高钾钙碱性过铝质辉绿玢岩;稀土元素总量变化不大(149.75×10~(-6)~155.11×10~(-6)),曲线为右倾型;δEu的变化范围为0.61~0.67,具弱负Eu异常。结合岩石地球化学图解,认为辉绿玢岩形成于板块俯冲条件下的陆—陆碰撞构造环境。  相似文献   

6.
对出露于西藏冈底斯弧背断隆带东段的强母错噶石英二长岩进行了锆石U-Pb年代学和全岩地球化学分析,并据此探讨了该岩体的形成演化过程与成岩时的大地构造背景。测试结果表明,强母错噶石英二长岩中的岩浆锆石U-Pb加权平均年龄为(50.84±0.71) Ma(MSWD=0.51)为始新世早期。石英二长岩ω(SiO_2)=64.34%~64.87%,ω(K_2O)=4.66%~4.76%,ω(Na_2O)=3.38%~3.42%,ω(CaO)=3.65%~3.72%,ω(Al_2O_3)=15.91%~16.08%,全碱含量(K_2O+Na_2O)为8.04%~8.15%,K_2O/Na_2O=1.38~1.41,属于准铝质(A/CNK=0.91~0.93)钾玄岩系列。强母错噶石英二长岩轻稀土元素(LREE)含量为(241.62~441.75)×10~(-6),重稀土元素(HREE)含量为(18.58~20.60)×10~(-6),(LREE/HREE=12.48~21.65),稀土元素配分模式为轻稀土元素强烈富集的右倾型,其(La/Yb)_N为15.38~33.79,具中等负Eu异常(δEu=0.60~0.67)。微量元素显示强母错噶石英二长岩相对富集大离子亲石元素,而Nb、Ta、Ti和P等高场强元素(HFSE)相对亏损,显示出火山弧环境背景下中等分异程度的I型花岗岩特征。强母错噶石英二长岩的形成可能与冈底斯带始新世早期强烈的岩浆作用和新特提斯洋板片断离引发的地壳增厚密切相关,大洋板片断离从而引起软流圈物质上涌,导致下地壳部分熔融并与上涌地幔混合形成壳幔混合岩浆。  相似文献   

7.
江西是华南白垩纪红色碎屑沉积岩系最发育的地区之一,且常夹有火山岩层。会昌岽背村一带红色沉积岩系底部的火山岩具有较高Si O2和Al2O3,较低的Mg O,Si O2=59.0%~64.6%(平均61.9%),Al2O3=15.5%~18.9(平均17.7%),Mg O=0.28%~0.92%(平均0.55%);富碱和钠,(Na2O+K2O)=7.19%~10.1%(平均9.70%),Na2O=6.50%~7.70%(平均7.03%),在Si O2-(Na2O+K2O)图解上落入碱性系列粗面岩或粗面英安岩范围;CIPW计算结果显示,标准矿物Ab=57.2%~65.7(平均60.5%),Q=6.07%~14.7%(平均9.95%),小于20%,属粗面岩。稀土总量较低,轻稀土明显富集,重稀土强烈亏损,Eu负异常不明显,∑REE=114×10-6~168×10-6,∑LREE=101×10-6~148×10-6,∑HREE=14.9×10-6~19.6×10-6,∑LREE/∑HREE=6.54~7.52,(La/Yb)N=24.9~34.2(平均27.4),δEu=0.81~1.10(平均0.98%),在稀土曲线图上呈明显的右倾,具高压型粗面岩的特征。较低的Y和Yb含量,较高的Sr含量和Sr/Y比值,Y=8.99×10-6~11.7×10-6(平均10.8×10-6),Yb=0.55×10-6~0.82×10-6(平均0.7×10-6),Sr=329×10-6~836×10-6(平均498×10-6),Sr/Y=36.5~71.8(平均48.2),具有埃达克岩的特征;在不相容元素蛛网图上显示富集大离子亲石元素(Cs,Rb,Ba,K等元素),强烈亏损高场强元素(Ta、Nd),具壳源的特征。较低的(87Sr/86Sr)i值、较高的εNd(t)和较小的TDM2值,(87Sr/86Sr)i=0.7074~0.7082(平均0.7077),εNd(t)=-1.99~-2.60(平均-2.29),TDM2=1 071 Ma~1 120 Ma(平均1094 Ma),具年轻下地壳部分熔融产物的特征。SHRIMP锆石U-Pb测年结果显示,14个分析点的206Pb/238U年龄变化范围为(114~108)Ma,加权平均年龄为(110.7±1.0)Ma,MSWD=0.47,指示地质时代属早白垩世晚期。上述特征显示,会昌岽背村一带红色沉积岩系底部的火山岩为早白垩世晚期加厚地壳背景下年轻下地壳部分熔融形成的埃达克质粗面岩。  相似文献   

8.
新疆准噶尔东北缘蕴都卡拉一带碱性花岗岩具有高硅(w(SiO_2)=72.40%-74.17%)、富碱(w(Na_2O+K_2O)=8.41%-10.40%)、低钛(w(TiO_2)=0.20%-0.40%)、贫钙(w(CaO)=0.38%-0.70%)的特征,岩石显著富集高场强元素Zr、Th、Y等,轻重稀土分馏明显(LREE/HREE为5.1-10.5),明显亏损Eu(δEu=0.19-0.26),稀土元素配分模式呈右倾海鸥型,Sr、Ba、Ti等元素的强烈亏损,与典型的A型花岗岩一致。岩石地球化学研究表明,蕴都卡拉一带A型花岗岩可能是下地壳先存的俯冲洋壳或富Nb玄武岩部分熔融的产物,形成于晚石炭世后造山的拉张构造环境,是准噶尔东北缘造山作用结束的标志。  相似文献   

9.
南祁连党河南山地区发育一些小规模的煌斑岩脉,岩脉穿插于前泥盆纪地层及岩体中,岩石w(SiO_2)=46.93%~56.82%,w(K_2O)=0.64%~4.12%,属钙碱性系列煌斑岩.稀土元素总量较低(1.534 5×10~(-4)~2.744 9×10~(-4)),轻稀土富集,重稀土相对亏损.强烈富集大离子亲石元素(Rb、Ba、La、Ce、Sr)和U、Pb,亏损高场强元素(Nb、Ta、Zr、Hf).岩石w(~(87)Sr)/w(~(86)Sr)=0.713 716~0.716 950,εNd(t)=-6.713 9~-8.3986,w(~(143)Nd)/w(~(144)Nd)=0.512 036~0.512 117,具有高Sr低Nd的特征.煌斑岩源岩具岛弧钙碱性玄武岩的性质,源区可能为EMⅠ型富集地幔.煌斑岩的形成指示党河南山地区在海西早期已经处于碰撞后的伸展阶段.  相似文献   

10.
辽宁中沟地区大地构造位置隶属于华北克拉通北部。区内岩浆活动频繁,元古代条痕状花岗岩广泛出露,从岩相学、地球化学等方面对中沟地区条痕状花岗岩进行系统分析,目的是探讨该地区构造背景及岩石成因意义。条痕状花岗岩主要为二长花岗岩,岩石中可见钙质和镁铁质角闪石,副矿物为榍石、锆石和磁铁矿,属于高钾钙碱性-钙碱性岩浆系列,A/CNK介于1.09~1.67,A/NK变化于1.11~2.18,为弱过铝质-过铝质岩石。SiO_2含量介于61.91~77.48、富碱(Na_2O+K_2O=1.78~8.58)、高铝(Al_2O_3=11.57%~19.30%)、低镁钙(MgO=0.07%~2.79%、CaO=0.19%~2.70%)的特征。稀土总量相对较高(ΣREE=109.72×10~(-6)~320.27×10~(-6))、轻稀土分馏系数(La/Sm)_N=2.86~10.91,重稀土分馏系数(Gd/Yb)_N=0.59~7.97,Eu为中等负异常(δEu=0.18~0.75),在构造判别图解上位于活动大陆边缘区域内,具有明显的俯冲带岩浆特征。结合区域演化历史认为,在古元古代期间,胶辽吉造山带存在向北俯冲的作用。  相似文献   

11.
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.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

15.
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。  相似文献   

16.
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.  相似文献   

17.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

18.
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-  相似文献   

19.
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-  相似文献   

20.
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  相似文献   

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