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1.
曹俊臣  阚学敏 《矿物学报》1994,14(3):292-297
本文采用X射线衍射、化学分析、穆斯鲍尔诺、EPR谱和红外光谱,对不同颜色的岫岩玉(岫玉)进行了测试。测试结果如下:绿色岫玉主要由叶蛇纹石组成,黄色岫玉由叶蛇纹石和利蛇纹石组成。穆斯鲍尔谱显示出Fe2+和Fe3+的两个双吸收特征。Fe2+:化学位移为1.122mm/s,四极分裂为2.701~2.721mm/s,占据八面体位置;Fe3+:化学位移为0.155~0.355mm/s,四极矩为0.337~0.470mm/s,占据四面体位置。电子顺磁共振谱显示出中心场0.336T附近,存在一个具有超精细结构的六重吸收,g≈2.0,与处于八面体上的高自旋Mn2+有关。在低场区(0.16T附近),出现两个吸收线,g分别为4.29和3.88,与处于四面体位置的Fe3+有关。红外光谱显示出与叶蛇纹石有关的OH-振动吸收带(3665~3670cm-1);在3690~3680cm-1间显示出与利蛇纹石有关的吸收肩。1070,980cm-1出现Si-O振动吸收,另尚有5个吸收带(610,560,445,400,300cm-1)。随着绿色的加重和质量的提高,岫玉中Fe2+和Mn2+的浓度也增加。证实了岫玉的绿色与Fe2+→Fe3+的荷移有关,岫玉的黄色与O2-→Fe3+荷移有关。  相似文献   

2.
辐照条件下绿柱石通道中顺磁配合物的ESR行为   总被引:2,自引:3,他引:2  
四川平武贫铁富碱型无色绿柱石通道中主要存在碱氢化物(NaH)、[Fe2(OH)4]^2 多聚合离子及OH自由基,在电子辐照作用下,通道中顺磁配合物的结构、带电性质及化学键易发生转型、裂解和变价,并形成自旋浓度不等的[H^0]i心(裂距为500G,g值分别为2.175,1.8774的二重超精细结构线)、[Fe^3 ]OH(g=2.0031)和[Fe4^3 ]s(g=4.3172)等辐照损伤心。[Fe^3 ]OH心属一种有效的电子陷阱,其热稳定性大于[Fe4^3 ]s心。绿柱石杂质铁离子的占位方式,与成矿物理、化学条件及成矿流体的pH值密切相关。由电子辐照作用而导致杂质离子价态的转变,属一种可逆的动态平衡过程。  相似文献   

3.
热处理电气石的物相转变   总被引:8,自引:0,他引:8  
通过差热分析(DTA)、热处理和X射线衍射分析(XRD)等手段,研究我国西北某地区产的黑色电气石在热处理过程中的相转变过程,实验发现850℃热处理2h,电气石晶体结构的[Si6O18]复三方环和[BO3]三角结构已开始破坏,并出现新的物相-莫来石(Al2.35Si0.64O4.82),铝硼氧化物(Al5BO9)和赤铁矿(Fe2O3);890℃时,电气石分解形成的莫来石(Al2.35Si0.63O4.82)和赤铁矿(Fe2O3)量增加,并有新物相(Al2O3)9。97(B2O3)1.99形成;1010℃时,莫来石合成体系的Si、Al和O的原子个数比发生了变化(Al4.868Si1.132O9.566),出现矽线石(Al2SiO5)、镁橄榄石(Mg2SiO4)、顽辉石(Mg(SiO)3)和镁铝硅硼酸盐(Mg2Al4Si4B4O37)等新物相。  相似文献   

4.
闪锌矿的吸收光谱和颜色的本质   总被引:1,自引:0,他引:1  
本文采用电子吸收光谱和分子轨道(MO)-能带理论模型,系统地研究了不同颜色的闪锌矿呈色的机理和本质。闪锌矿由于其形成条件不同,所含杂质元素各异而颜色变化。黑色闪锌矿含Fe高,其颜色是由于以配位体硫为特征的非键轨道2e到Fe^2 的晶体场型轨道的电子转移在500nm产生吸收所致。只有闪锌矿含Fe低(<1%)时,它才可具有其他颜色,黄色与受主能级Cu^ 到导带或价带到施主能级Ga^3 的电子跃迁在410nm产生吸收有关;绿色是Co^2 的晶体场跃迁^4A2→^4T2(P)在700nm附近产生的吸收峰所致;红色可能与受主能级Hg^ 到施主能级Ga^3 的电子跃迁在470nm产生宽吸收带有关。当闪锌矿的吸收光谱有其中两个吸收带叠加时,它具有过渡的颜色,如黄绿色或绿黄色、桔黄色或桔红色,主要色调取决于两个吸收带的相对强度。  相似文献   

5.
天然半导体矿物金红石因结构中含有类质同象替代杂质元素V和Fe,具有一定的可见光吸收和光催化活性。为改善金红石的日光光催化性能,在H2还原气氛下,对天然金红石粉末进行500~900℃不同温度的热处理改性研究。紫外-可见漫反射吸收光谱(UV-Vis diffuse reflectance absorption spectra)表明H2还原处理显著改善了金红石在可见光区460~750 nm波段的光吸收,其中900℃处理样品的光吸收提升最为明显。电子顺磁共振(EPR)和X射线光电子能谱(XPS)测试表明,随着还原温度升高,杂质元素V和Fe从高价态(V5+,Fe3+)向较低的价态(V4+,V3+,Fe2+)转化,同时金红石表面的化学吸附水含量也有所增加。本文认为H2还原热处理引起的过渡金属元素价态的改变,尤其是较低氧化态V离子(V4+和V3+)的形成,可能是导致金红石样品可见光吸收显著增加的主要原因。  相似文献   

6.
采用X射线荧光光谱、X射线衍射图谱、紫外可见光吸收光谱等分析方法,对鄂西贡水砚石进行成分、结构的表征,用贮墨实验表征砚石的性能,对砚石开发进行可行性分析。结果表明,鄂西贡水砚石主要矿物成分为白云石、方解石、水云母以及石英。可见光谱吸收峰位于378 nm、437 nm和540 nm附近,分别为Fe3+由6A1g基态到4A1g或4Eg的跃迁、氧八面体中Fe3+的电子跃迁吸收及氧八面体中Fe2+的自旋禁戒跃迁所致。光学显微镜下矿物排列致密,孔隙度极小,多在0.01 mm以下,砚峰密度0.6~0.7个/μm2,砚石类型属于中锋砚石。不同条件下贮墨时长1.3~60.0 h。为鄂西砚石的开发提供科学依据。  相似文献   

7.
李艺  赖来仁 《矿产与地质》2003,17(2):170-172
广西德保矿区产出的结晶为双锥状的臭葱石的主要化学成分为Fe2O3 34.5%,As2O5 47.75%;而呈葡萄状的臭葱石含Fe2O3 26.67%,As2O5 44.28%, 它们的FeAs≈1,与理想分子式FeAsO4*2H2O接近.根据该矿物(德保)的粉晶X射线分析数据用最小二乘法计算的晶胞参数为a0=10.28(A),b0=10.00(A),c0=8.90(A).Z=8,为斜方晶系,空间群为Pcab.红外吸收光谱分析显示有波数为3505、3420、3000、820、720、490、470、435、415(cm-1)等吸收带.差热分析显示有256℃、945℃和980℃三个明显的吸热谷,还显示有520℃、725℃两个小的放热峰.  相似文献   

8.
福建明溪蓝宝石矿物学特征及致色机理探讨   总被引:2,自引:4,他引:2  
利用颜色测量、顺磁共振谱、红外光谱和热谱等方法研究明溪蓝宝石的矿物学特征和结构特性,明溪蓝宝石色深,蓝中带黄,二色性强,分析表明Fe主要以Fe^3 形式存在,Fe^3 的d-d电子跃迁和Fe^2 -Ti^4 、O-Fe境塌菏转移是明溪蓝宝石致色的主要因素;H含量对蓝色的形成有重要作用。  相似文献   

9.
在适当的热处理条件下,黄绿色绿柱石能够转变为理想颜色的海蓝宝石。天然海蓝宝石与热处理海蓝宝石的价格差异较大,因此探索热处理海蓝宝石的诊断性鉴定特征就显得十分必要。对不同温度下热处理海蓝宝石进行傅里叶变换红外光谱和激光拉曼光谱的测试分析,结果发现,当热处理温度超过400℃后,随着加热温度的升高,在红外光谱中由[Fe2(OH)4]2+伸缩振动gI起的3233cm叫处吸收谱峰明显减弱,直至消失。5268cm叫附近由水伸缩和弯曲振动}I起合频区的吸收带由尖峰变得宽缓;8700,6818cm叫两处水吸收峰的相对强度也随着加热温度升高而减弱。热处理海蓝宝石Si-0-Si伸缩振动产生的在682,3604cm叫处的拉曼光谱谱峰强度随着加热温度升高逐渐减弱,1070cm“处的拉曼峰强度明显降低。经700℃加热后,拉曼光谱基线明显向上方漂移。这些光谱特征变化对热处理海蓝宝石的鉴定有重要意义。  相似文献   

10.
Mg-Fe电气石的热膨胀与相变   总被引:5,自引:0,他引:5  
对Mg-Fe系列的两种电气石进行了不同温度下的热膨胀与相变研究,发现电气石在900℃以下保持稳定,900-950℃分解,镁电气石分解为堇青石-α与非晶质,黑电气石分解为赤铁矿与Al5(BO3)O6。加热过程中电气石晶胞大小发生变化,是晶体热膨胀与Fe^2 →Fe^3 替代、OH^-→O^2-替代综合作用的结果。在含Fe的电气石中,晶胞收缩幅度取决于电气石中Fe^2 的含量;800℃时,Fe^2 完全氧化,表面赤铁矿晶出,晶胞收缩显著。电气石的热膨胀率为锂电气石>镁电气石>黑电气石;c轴>a轴。  相似文献   

11.
Pant-y-ffynnon Quarry in South Wales yielded a rich cache of fossils in the early 1950s, including articulated specimens of new species (the small sauropodomorph dinosaur Pantydraco caducus and the crocodylomorph Terrestrisuchus gracilis), but no substantial study of the wider fauna of the Pant-y-ffynnon fissure systems has been published. Here, our overview of existing specimens, a few described but mostly undescribed, as well as freshly processed material, provides a comprehensive picture of the Pant-y-ffynnon palaeo-island of the Late Triassic. This was an island with a relatively impoverished fauna dominated by small clevosaurs (rhynchocephalians), including a new species, Clevosaurus cambrica, described here from a partially articulated specimen and isolated bones. The new species has a dental morphology that is intermediate between the Late Triassic Clevosaurus hudsoni, from Cromhall Quarry to the east, and the younger C. convallis from Pant Quarry to the west, suggesting adaptive radiation of clevosaurs in the palaeo-archipelago. The larger reptiles on the palaeo-island do not exceed 1.5?m in length, including a small carnivorous crocodylomorph, Terrestrisuchus, and a possible example of insular dwarfism in the basal dinosaur Pantydraco.  相似文献   

12.
Lithostratigraphy, physicochemical stratigraphy, biostratigraphy, and geochronology of the 77–70 Ma old series bracketing the Campanian–Maastrichtian boundary have been investigated by 70 experts. For the first time, direct relationships between macro- and microfossils have been established, as well as direct and indirect relationships between chemo-physical and biostratigraphical tools. A combination of criteria for selecting the boundary level, duration estimates, uncertainties on durations and on the location of biohorizons have been considered; new chronostratigraphic units are proposed. The geological site at Tercis is accepted by the Commission on Stratigraphy as the international reference for the stratigraphy of the studied interval. To cite this article: G.S. Odin, C. R. Geoscience 334 (2002) 409–414.  相似文献   

13.
Robert L. Linnen   《Lithos》2005,80(1-4):267-280
The solubilities of columbite, tantalite, wolframite, rutile, zircon and hafnon were determined as a function of the water contents in peralkaline and subaluminous granite melts. All experiments were conducted at 1035 °C and 2 kbar and the water contents of the melts ranged from nominally dry to approximately 6 wt.% H2O. Accessory phase solubilities are not affected by the water content of the peralkaline melt. By contrast, solubilities are affected by the water content of the subaluminous melt, where the solubilities of all the accessory phases examined increase with the water content of the melt, up to 2 wt.% H2O. At higher water contents, solubilities are nearly constant. It can be concluded that water is not an important control of accessory phase solubility, although the water content will affect diffusivities of components in the melt, thus whether or not accessory phases will be present as restite material. The solubility behaviour in the subaluminous and peralkaline melts supports previous spectroscopic studies, which have observed differences in the coordination of high field strength elements in dry vs. wet subaluminous granitic glasses, but not for peralkaline granitic glasses. Lastly, the fact that wolframite solubility increases with increasing water content in the subaluminous melt suggests that tungsten dissolved as a hexavalent species.  相似文献   

14.
Some olistolites reworked in a Tertiary flysch of Mount Parnon (Peloponnesus, Greece) exhibit a Late Permian assemblage, dominated by Paradunbarula (Shindella) shindensis, Hemigordiopsis cf. luquensis and Colaniella aff. minima. This association corresponds to the Late Wuchiapingian (=Late Dzhulfian), a substage whose algae and foraminifera are generally little known. Contemporaneous limestones crop out in the middle part of the Episkopi Formation in Hydra, but they are rather commonly reworked in Mesozoic and Cainozoic sequences. The palaeobiogeographical affinities shared by the foraminiferal markers of Greece, southeastern Pamir, and southern China, are very strong (up to the specific level), and are congruent with the Pangea B reconstructions. To cite this article: E. Skourtsos et al., C. R. Geoscience 334 (2002) 925–931.  相似文献   

15.
PALEONTOLOGY     
正20141596 Liu Yunhuan(School of Earth Sciences and Resources,Chang’an University,Xi’an 710054,China);Shao Tiequan Early Cambrian Quadrapyrgites Fossils of Xixiang Boita in Southern Shaanxi Province(Journal of Earth Sciences and Environment,ISSN1672-6561,CN61-1423/P,35(3),2013,p.39-43,3 illus.,20 refs.)  相似文献   

16.
正20141719 Chen Zhijun(State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences,Wuhan 430074,China);Chen Jianguo Automated Batch Mapping Solution for Serial Maps:A Case Study of Exploration Geochemistry Maps(Journal of Geology,ISSN1674-3636,CN32-1796/P,37(3),2013,p.456-464,2 illus.,2 tables,10 refs.)  相似文献   

17.
正20140962 Chen Fenning(Xi’an Institute of Geology and Mineral Resources,Xi’an710054,China);Chen Ruiming Late Miocene-Early Pleistocene Ostracoda Fauna of Gyirong Basin,Southern Tibet(Acta Geologica Sinica,ISSN0001-5717,CN11-1951/P,87(6),2013,p.872-886,6illus.,56refs.)  相似文献   

18.
PETROLOGY     
正1.IGNEOUS PETROLOGY20142008Cai Jinhui(Wuhan Center,China Geological Survey,Wuhan 430205,China);Liu Wei Zircon U-Pb Geochronology and Mineralization Significance of Granodiorites from Fuzichong Pb-Zn Deposit,Guangxi,South China(Geology and Mineral Resources of South China,ISSN1007-3701,CN42-1417/P,29(4),2013,p.271-281,7illus.,  相似文献   

19.
正20141205Cheng Weiming(State Key Laboratory of Resources and Environmental Information System,Institute of Geographic Sciences and Natural Resources Research,CAS,Beijing 100101,China);Xia Yao Regional Hazard Assessment of Disaster Environment for Debris Flows:Taking Jundu Mountain,Beijing as an  相似文献   

20.
正20141266Fan Chaoyan(Guangdong Provincial Key Laboratory of Mineral Resources and Geological Processes,Guangzhou 510275,China);Wang Zhenghai On Error Analysis and Correction Method of Measured Strata Section with Wire Projection Method(Journal of  相似文献   

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