玄武岩纤维原料特征的统计及分析研究     

李珎  徐冠立  刘荣  史凯文 《地质论评》2023,69(4):2023040019-2023040019

玄武岩纤维是以玄武岩或他种成分相近的岩石为主要原料,经熔融后拉制而成的一种高性能纤维。天然矿石的成分波动会造成拉丝困难或纤维性能不稳定,本文收集了54组原料岩石以及114组玄武岩纤维样品的化学成分数据,研究归纳了玄武岩纤维所需原料的岩石学特征、参数指标特征和其他特征,分析提出了可拉丝岩石相关参数指标的最佳区间。适于生产玄武岩纤维的原料矿石,其特征可总结如下：岩石学方面,以基性岩以及SiO2含量为53%~57%的中性岩为佳,岩石类型最佳为玄武岩或安山玄武岩;岩石结构最佳为间隐结构、玻基斑状结构或玻璃质结构;构造的影响是间接的,主要为气孔或杏仁构造中可能含有的一些不利矿物的影响;矿物组成方面,蛇纹石、沸石等含水矿物会在熔融过程中产生气泡,影响纤维制备连续性的同时也有利于原料的充分熔融,镁橄榄石、磁铁矿等高熔点矿物会使原料在熔融阶段难以完全熔化,导致熔体不均匀并容易析晶。参数指标方面,可拉丝岩石的酸度系数（Mk）最佳区间为4.0~5.5;黏度系数（Mv）为2.0~3.0;硅铝氧化物与其他氧化物比值为1.5~3.0;氧化物组成的物质的量分数分布为n(RO)=20%~30%,n(RO2)=57%~70%,n(R2O3)=10%~16%（R为阳离子）。  相似文献   

Effects of Spin Transition and Cation Substitution on the Optical Properties and Iron Partitioning in Carbonate Minerals     

HU Jun  XU Liangxu  LIU Jin  YUE Donghui 《《地质学报》英文版》2023,97(1):350-357

The high-pressure behavior of deep carbonate dictates the state and dynamics of oxidized carbon in the Earth’s mantle, playing a vital role in the global carbon cycle and potentially influencing long-term climate change. Optical absorption and Raman spectroscopic measurements were carried out on two natural carbonate samples in diamond-anvil cells up to 60 GPa. Mg-substitution in high-spin siderite FeCO₃ increases the crystal field absorption band position by approximately 1000 cm  相似文献   

Cr-Saturation Arrays in Concentrate Garnet Compositions from Kimberlite and their Use in Mantle Barometry   总被引：2，自引：0，他引：2  

GRUTTER  HERMAN; LATTI  DEWETIA; MENZIES  ANDREW 《Journal of Petrology》2006,47(4):801-820

The spinel–garnet transition in Cr/Al-enriched peridotiticbulk compositions is known from experimental investigationsto occur at 20–70 kbar, within the pressure range sampledby kimberlites. We show that the Cr₂O₃–CaO compositionsof concentrate garnets from kimberlite have maximum Cr/Ca arrayscharacterized by Cr₂O₃/CaO petrology.oxfordjournals.org/math/sim.gif" ALT="~" BORDER="0">0·96–0·81, andinterpret the arrays as primary evidence of chromite–garnetcoexistence in Cr-rich harzburgitic or lherzolitic bulk compositionsderived from depth within the lithosphere. Under Cr-saturatedconditions on a known geotherm, each Cr/Ca array implicitlydelineates an isobar inside a garnet Cr₂O₃–CaO diagram.This simplification invites a graphical approach to calibratean empirical Cr/Ca-in-pyrope barometer. Carbonaceous chromite–garnetharzburgite xenoliths from the Roberts Victor kimberlite tightlybracket a graphite–diamond constraint (GDC) located atCr₂O₃ = 0·94CaO + 5·0 (wt %), representing a pivotalcalibration corresponding to 43 kbar on a 38 mW/m² conductivegeotherm. Additional calibration points are established at 14,17·4 and 59·1 kbar by judiciously projecting garnetcompositions from simple-system experiments onto the same geotherm.The garnet Cr/Ca barometer is then simply formulated as follows(in wt %):

if Cr₂O₃ petrology.oxfordjournals.org/math/ge.gif" ALT="≥" BORDER="0"> 0·94CaO + 5, then P₃₈ (kbar) = 26·9+ 3·22Cr₂O₃ – 3·03CaO, or

if Cr₂O₃ <0·94CaO + 5, then P₃₈ (kbar) = 9·2+ 36[(Cr₂O₃+ 1·6)/(CaO + 7·02)].

A small correction to P₃₈ values, applicable for 35–48mW/m² conductive geotherms, is derived empirically by requiringconventional thermobarometry results and garnet concentratecompositions to be consistent with the presence of diamondsin the Kyle Lake kimberlite and their absence in the Zero kimberlite.We discuss application of the P₃₈ barometer to estimate (1)real pressures in the special case where chromite–garnetcoexistence is known, (2) minimum pressures in the general casewhere Cr saturation is unknown, and (3) the maximum depth ofdepleted lithospheres, particularly those underlying Archaeancratons. A comparison with the P_Cr barometer of Ryan et al.(1996, Journal of Geophysical Research 101, 5611–5625)shows agreement with P₃₈ at 55 ± 2 kbar, and 6–12%higher P_Cr values at lower P₃₈. Because the P_Cr formulationsystematically overestimates the 43 kbar value of the GDC by2–6 kbar, we conclude that the empirical Cr/Ca-in-garnetbarometer is preferred for all situations where conductive geothermsintersect the graphite–diamond equilibrium. KEY WORDS: Cr-pyrope; chromite; P₃₈ barometer; mantle petrology; lithosphere thickness  相似文献   

GGR Biennial Review: Key Advances in Secondary Ion Mass Spectrometry in the Geological Sciences during the Period 2008–2009     

Michael Wiedenbeck 《Geostandards and Geoanalytical Research》2010,34(4):387-394

Secondary ion mass spectrometry (SIMS or ion microprobe) remains one of the most powerful techniques in the analytical geochemist’s toolkit. The key strength of SIMS is its capacity to provide trace element and isotope data at sampling sizes which are not approached by other methods. As compared with the main competing technique of laser ablation-ICP-MS, SIMS commonly provides a total sampling mass some 10 to 500 times smaller; this feature can be the deciding factor as to whether an analytical objective is technically achievable. Additional strengths of SIMS lie in the areas of depth profiling and trace element imaging. Though perhaps not as commonly used in the geosciences, these two operational modes represent unique capabilities of SIMS.  相似文献   

宣东矿区下花园组岩矿、煤岩及孢粉组合特征     

张树胜  范志强  马秀民  肖学军  王凤清 《中国煤炭地质》2010,(10):5-9

河北宣东矿区含煤地层为中侏罗统下花园组,含有5个煤组,煤层多,标志层不发育,煤层对比较为困难。钻孔岩、煤心样品的岩矿、煤岩鉴定和孢粉分析等成果资料揭示:①长石砂岩主要赋存于Ⅲ煤组岩段及其以上地层,Ⅴ煤组岩段分布极少;安山岩屑砂岩集中分布在Ⅴ煤组顶底板附近,Ⅲ煤组岩段及其以上岩段未见;泥化安山岩屑砂岩仅分布在Ⅴ煤组岩段的下部;石英砂岩分布在Ⅴ煤组岩段底部与煤系基底地层接触处;鲕状粘土岩仅分布于Ⅴ煤组岩段下部,并常为煤组底板。②Ⅰ、Ⅱ、Ⅲ煤组显微煤岩类型以微镜煤、微亮煤为主;Ⅳ、Ⅴ煤组多为角质微亮煤、微亮暗煤及丝炭微暗煤。③Ⅰ、Ⅱ煤组的裸子植物花粉含量丰富,占孢粉总数的40%～60%;Ⅲ煤组低于Ⅰ、Ⅱ煤组;Ⅴ煤组除克拉梭粉及苏铁粉含量占15%左右外,其它松科花粉少见。该结论可作为矿区岩、煤组(层)划分和对比的依据,对指导煤矿开采生产和邻区的勘查工作具有实际意义。  相似文献   

从砂岩成分探讨吐哈盆地构造演化   总被引：9，自引：1，他引：9       下载免费PDF全文

邵磊  Stattegger. 《地质论评》2001,47(1):19-26

陆源碎屑岩是陆相沉积盆地的主要充填物，其成分主要受物源区母岩成分控制。通过系统分析碎屑岩成分特点可以再造沉积盆地的构造演化历史。对吐哈盆地分别采用岩矿和地球化学分析手段进行系统分析，结果显示两种分析所得结构吻合性极好，反映盆地的构造演化分为二叠纪、三叠纪－侏罗纪以及白垩纪－第三纪3个演化阶段，在各阶段地层成分出现较大差异，是盆地及相邻地区遭受构造运动改造的结果。  相似文献   

Experimental constraints on pre-eruptive water contents and changing magma storage prior to explosive eruptions of Mount St Helens volcano   总被引：2，自引：0，他引：2  

J. E. Gardner  M. Rutherford  S. Carey  H. Sigurdsson 《Bulletin of Volcanology》1995,57(1):1-17

Compositionally diverse dacitic magmas have erupted from Mount St Helens over the last 4000 years. Phase assemblages and their compositions in these dacites provide information about the composition of the pre-eruptive melt, the phases in equilibrium with that melt and the magmatic temperature. From this information pre-eruptive pressures and water fugacities of many of the dacites have been inferred. This was done by conducting hydrothermal experiments at 850°C and a range of pressures and water fugacities and combining the results with those from experiments at temperatures of 780 and 920°C, to cover the likely range in equilibration conditions of the dacites. Natural phase assemblages and compositions were compared with the experimental results to infer the most likely conditions for the magmas prior to eruption. Water contents disolved in the melts of the dacites were then estimated from the inferred conditions. Water contents in the dacites have varied greatly, from 3.7 to 6.5 wt.%, in the last 4000 years. Between 4000 and about 3000 years ago the dacites tended to be water saturated and contained 5.5 to 6.5 wt.% water. Since then, however, the dacites have been significantly water-undersaturated and contained less than 5.0 wt.% water. These dacites have tended to be hotter and more mafic, and andesitic and basaltic magmas have erupted. These changes can be explained by variable amounts of mixing between felsic dacite and basalt, to produce hotter, drier and more mafic dacites and andesites. The magma storage region of the dacitic magmas has also varied significantly during the 4000 years, with shifts to shallower levels in the crust occurring within very short time periods, possibly even two years. These shifts may be related to fracturing of overlying roof rock as a result of magma with-drawal during larger volume eruptions.  相似文献   

塔里木盆地吉拉克地区三叠系储层岩石学与地层损害分析     

沈守文  康毅力 《矿物岩石》1995,15(4):51-57

本文在分析塔里木盆地吉拉吉地区三叠系储层岩石学特征的基础上，探讨了潜在的地层损害因素。文章指出，塔里木盆地吉拉吉地区三叠系地层损害以水敏和碱敏为主，速敏和酸敏次之，还存在出砂的危险，且不宜采用酸化增产措施。  相似文献   

微束分析技术在有机岩石学研究中的应用现状     

刘大锰 《地质科技情报》1995,14(2):91-97

介绍了扫描电镜能谱、透射电镜、二次离子质谱、激光微探针质谱、显微傅立叶红外光谱等几种微束分析技术的性能特点，系统地论述了其在有机岩石学在应用现状与进展，并较详细地阐述了利用上述技术研究塔里木盆地烃源岩显微组分的结果。  相似文献   

新疆东准噶尔北部碱性花岗岩的特征、成因及构造意义   总被引：24，自引：2，他引：24  

忻建刚  袁奎荣 《大地构造与成矿学》1995,19(3):214-226

新疆东准噶尔北部的碱性花岗岩呈带状分布于乌伦古断裂及额尔齐斯─玛因鄂博断裂之间地区。碱性花岗岩以出现碱性暗色矿物及铁质黑云母为特征，高硅、高碱、低钙、低镁铁，富含高场强元素，属典型的Ａ型花岗岩，它们产出的特定构造环境，据化学成分的构造环境判别为板内非造山的裂谷环境；成因类型相当于Ｅｂｙ（１９９２）的Ａ１类Ａ型花岗岩，明显不同于东准噶尔中部及南部碱性花岗岩带产出的造山期后张性构造环境。  相似文献