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1.
对赣中相山铀矿田新元古代变质岩基底的稀土元素地球化学特征进行分析。结果表明,稀土总量较高,为(127.47~288.40)×10-6,平均为197.18×10-6;∑LREE/∑HREE比值为7.03~10.16,平均为8.66,明显富集LREE。δEu为0.57~0.79,平均0.70,显示中等或弱的负异常;δCe为0.44~1.04,平均为0.90,显示弱的负异常或无异常。三组岩石稀土配分模式类似,表明具有相近的物源,其原岩应属于陆源碎屑岩,岩石的物源很可能来自华夏大陆;据稀土元素含量及其比值,推测该测区变质岩形成的沉积构造背景为大陆岛弧环境。同时ΣREE-La/Yb图解表明,神山组样品原岩主要为页岩和粘土岩,上施组原岩主要为砂岩,库里组原岩大多为砂岩,同时含有页岩和粘土岩。  相似文献   

2.
对扬子地台南缘元古代浊积岩的常量元素和微量元素地球化学研究表明,源区遭受了中等程度的风化作用影响,这种影响记录在碱金属和碱土金属元素的丰度与分布型式、蚀变化学指数(CIA)以及Th/U比值等方面。稀土元素的组成和配分型式、Th/Sc和La/Sc比值以及其他常量和微量元素之间的关系表明,沉积岩不具备成熟的再旋回沉积物的特征,其源岩主要为由酸性岩浆岩等长英质组分构成的古老上地壳,源岩曾受到了显著的壳内分异作用的影响。中元古界冷家溪群地层的源岩较新元古界板溪群合有较高的Co,Cr,Ni,Sc,V等基性组分,且基性的铁镁质成分主要反映在粘土级组分的沉积记录中。  相似文献   

3.
塘湾岩体位于诸广岩体中南部,岩性主要为中细粒斑状二云母花岗岩。对塘湾岩体进行了详细的主量元素、微量元素和稀土元素的研究。结果表明,该岩体表现为高钾钙碱性,SiO_2含量高(72.76%~74.32%,平均值为73.50%),富碱(Na_2O+K_2O=7.61%~8.50%,平均值为8.07%),且钾大于钠,铝过饱和(A/CNK值介于1.03~1.12之间,平均1.07)的特点。微量元素中富集Rb,Th,U,Ce,Zr,Hf,明显亏损Sr,P,Ti,Ta,岩体铀含量较高,Th/U比值低,岩体中的铀多受到了活化改造,对铀成矿有利;稀土元素具有总含量不高,配分模式呈右倾型,轻、重稀土分馏明显,以及强烈的铕负异常等特征。推测其形成于岩石圈伸展减薄的环境下,源区由泥质岩(主要)和砂质岩(次要)混合组成。  相似文献   

4.
湘西民乐地区沉积了一套新元古代马底驿组-寒武纪纽芬兰世牛蹄塘组的浅变质板岩类,地层倾角为10°~20°,南东向倾向,层理发育。为了探讨该区的浅变质板岩类的原岩特征和原岩形成时大地构造环境,本文采用等离子体质谱分析仪对样品进行稀土元素分析测试。结果表明:板岩类稀土元素总量REE,轻、重稀土比和Eu,Ce的异常与沉积岩基本一致,表明了民乐地区板岩类的原岩与沉积岩近似。由ΣREE-La/Yb图解和稀土元素特征与不同大地构造背景沉积岩的稀土元素特征比较,得出变质板岩类的原岩为沉积的碎屑物质(火山喷发的玄武岩、泥岩和杂砂岩)形成沉积岩,大地构造环境为活动大陆边缘。  相似文献   

5.
以南羌塘坳陷早侏罗系曲色组下部的泥岩为研究对象,对其进行地球化学的研究。微量元素分析结果表明,曲色组泥岩沉积有较多的陆源物质,且Cr/Zr、Th/Sc、Th/U、Rb/Sr的值反映了泥岩物源区具有浅源、长英质、风化较严重的特点。稀土元素特征表明泥岩重稀土较轻稀土元素富集,具有轻微的Ce与Eu的负异常。通过Ceanom、V/(Ni+V)与CIA的值判断泥岩沉积时处于缺氧的沉积环境,且当时处于温暖潮湿的气候。通过La-Th-Sc和Th-Co-Zr/10物源区构造判别图,再结合La/Th的值与Hf的含量,判断曲色组泥岩的物源区构造背景以大陆岛弧为主,且兼具大陆边缘构造的特征。  相似文献   

6.
地处黄河三门峡段下游冲积平原附近的邙山黄土,中更新世晚期以来沉积厚度近100 m,远大于洛川、渭南等典型黄土剖面的同期堆积。前人从沉积速率、粒度等方面进行研究,推测邙山黄土堆积可能源于三门峡段下游的冲积物,但尚无微量和稀土元素地球化学方面的证据。对黄土中古土壤S_2沉积以来的邙山黄土及三门峡地区黄土进行了微量元素和稀土元素测试,并与黄土高原、淮南等地区典型黄土的元素地球化学特征进行了对比。结果表明,与黄土高原等典型黄土相比,邙山黄土明显富Zr、Hf贫Th、Cs,在Zr/Hf、Nb/Th、Y/Th、La/Th等元素比值上差异显著;La-Th-Sc和Th-Sc-Zr/10三角图解也显示,邙山黄土与黄土高原等典型黄土的投影区域明显不同。在稀土元素特征上,邙山黄土在ΣREE及表征REE内部分馏程度的LREE/HREE、La/Eu上与黄土高原等典型黄土存在明显不同,10*Hf-Ce-Yb和La-Zr/10-Ce三角图解中的投影区域也与其他典型黄土有显著区别。微量元素及稀土元素地球化学特征显示,邙山黄土与黄土高原等典型黄土的物源可能并不完全一致,邙山黄土可能相当一部分源于近源冲积物。邙山附近广阔的黄河冲积平原可能是S2以来邙山黄土巨厚堆积的重要物源区。  相似文献   

7.
目的探讨天水地区上泥盆统大草滩群变砂岩形成的构造环境。方法利用砂岩常量元素、微量元素和稀土元素地球化学分析,结合区域地质研究。结果天水地区上泥盆统大草滩群主要为变砂岩、粉砂岩、泥质岩石,其中的变砂岩地球化学具有相对低SiO2,Na2O,高TiO2,MgO,Fe2O3,A l2O3的特征;富集Nb,Co,La,Ce,Nd,亏损Sc,Th,Hf以及La/Th,La/Sc,Th/Sc,Ti/Zr,Zr/Hf等特征参数与大陆岛弧和活动大陆边缘构造环境沉积物相似。结论天水地区上泥盆统大草滩群中的变砂岩碎屑来源于活动大陆边缘。  相似文献   

8.
南江坪河石墨矿是四川省典型的含钒晶质石墨矿,在对坪河石墨矿变质岩岩相学和岩石地球化学特征研究的基础上,分析了变质岩的原岩类型及其古沉积环境。变质岩样品的ω_(SiO_2)/ω_(Al_2O_3),ω_(K_2O)/ω_(Na_2O),ω_(Eu)/ω_(Sm),ω_(Rb)/ω_(Sr),ω_(Sr)/ω_(Ba)值均表明原岩物质来源为陆源碎屑沉积;(ω_(La)/ω_(Yb))_N,δ_(Eu),δ_(Ce)均值分别为7.67,0.75,0.81,反映轻、重稀土分馏程度较高并呈轻微Eu,Ce负异常的特征。原岩恢复相关判别图解显示其原岩是一套以含炭质黏土细-粉砂岩为主,夹少量泥质砂岩、基性岩的岩石组合,具有明显的前寒武纪陆源碎屑河流与边缘海沉积的特点。古水体氧化-还原环境微量元素判别指标、ω_(Ba)-ω_(Sr)图解和不同气候带黏土岩的成分图解均揭示其形成于干燥气候带条件下缺氧静水低能的泻湖环境,古水体介质主要为陆相淡水。  相似文献   

9.
库鲁克塔格震旦系冰碛岩样品的常量元素、微量元素和稀土元素(REEs)特征表明,Na2O,Ba和HREE比太古代后页岩富集,Sr,Cr,Co,Ni和Sc则相对亏损;其他元素与NASC和PAAS特征相似.地球化学特征指示库鲁克塔格震旦系冰碛岩主要来源于以长英质岩石为主的物源区.K2O/Al2O3低的比值,表明源区物质中的碱性长石含量较低.库鲁克塔格震旦系冰碛岩的REE配分模式和负Eu异常特征表明它们的物源区中老地壳的组分占较大的比例,发生过壳内分异作用.高的Na2O的含量和(La/Yb)n>2的特征说明它们的成熟度低于PAAS和NASC.化学蚀变指数(CIA值)指示库鲁克塔格震旦系冰碛岩的物源区古风化程度较低.一些样品表现高K的特征,在Al2O3-(CaO* Na2O)-K2O(A-CN-K)三角图中表现为向K顶点方向上偏移,表明这些冰碛岩在沉积期后发生了不同程度的钾交代.  相似文献   

10.
在矿床地质研究基础上,通过对13件锰矿石样品进行系统的主量元素、稀土元素测试及分析,进一步探讨高燕锰矿床的成矿物质来源及沉积环境。结果表明:Mn/Fe平均值为17.34,P/Mn平均值为0.008,(CaO+MgO)/(SiO_2+Al_2O_3)平均值为0.51,因此城口锰矿属于高磷低铁偏酸性锰矿石。Mn含量远高于TFe与MgO含量,可能是Fe~(2+)、Mg~(2+)易进入锰矿石的晶格占据Mn~(2+)的位置而形成完全类质同象的原因;Al和Ti含量相对较低,表明锰矿石沉积水体相对较深或距离陆源较远。高燕锰矿稀土元素总量不大,轻稀土明显较重稀土富集,δEu呈正异常,δCe呈弱的正异常。SiO_2/Al_2O_3、Fe/Ti、(Fe+Mn)/Ti、Al/(Al+Fe+Mn)、La/Ce比值,以及SiO_2-Al_2O_3、La-Ce、La/Yb-REE图解都显示出锰矿沉积过程中有大量热水(液)的注入,受陆源物质的影响程度较小,物源可能来自洋壳深部;锰矿与底板围岩稀土元素配分曲线相似,且锰矿层的产出严格受区域构造、地层、岩性的控制,反映了底板围岩可能为锰矿层的形成提供了部分物质来源;Sm/Nd比值指示锰矿层的沉积类型为壳层源沉积。Mn/Fe、ΣLREE/ΣHREE比值及δCe值,Ce、Eu异常,以及La_N/Ce_N-Al_2O_3/(Al_2O_3+Fe_2O_3)图解表明城口高燕锰矿床形成于大陆边缘向深海盆地过渡范围内即离岸较远、相对潮湿的深海或深水,还原、成矿温度大于250℃的沉积环境。  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.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

19.
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   

20.
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   

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