叶蜡石加热相变及其演化特征   总被引：4，自引：1，他引：3  

魏存弟  赵峰  马鸿文  李金洪  杨殿范  三国彰 《吉林大学学报(地球科学版)》2005,35(2):150-154

通过对叶蜡石20～1 300℃热处理产物进行系统的差热分析、X射线衍射分析和红外光谱分析等的研究,发现叶蜡石加热相变过程具有明显的阶段性.根据主要物相及其变化和组合特征,可以将叶蜡石的加热相变过程分为4个阶段,即叶蜡石阶段(室温～660℃)、偏叶蜡石阶段(660～1 100℃)、不定形SiO2 与莫来石形成阶段(1 100～1 200℃)、莫来石与方石英共存阶段(≥1 300℃).  相似文献   

Preparation and characteristics of porous ceramics   总被引：2，自引：0，他引：2  

Dongmei SHAO  Peiping ZHANG  Liyan MA  Juanjuan LIU 《世界地质(英文版)》2007,10(2)

Pyrophyllite is always used for making porous ceramics. In order to design the preparation technics of porous ceramics with pyrophyllite reasonably we must know the classifications, characteristics, properties and applications of porous ceramics. The classification and characteristics of porous ceramics are reviewed in this article; and several common preparations with their advantages and disadvantages are also introduced. The authors discussed the problems existing in researching and developing process for porous ceramics, and forecasted the development prospect of porous ceramics.  相似文献   

Mg–Fe carpholites from aluminous schists in the Diahot region and implications for preservation of high-pressure/low-temperature schists, northern New Caledonia     

P. M. BLACK  P. MAURIZOT  E. D. GHENT  M. Z. STOUT 《Journal of Metamorphic Geology》1993,11(3):455-460

Abstract Mg–Fe carpholite is widespread in the Diahot region of New Caledonia in highly aluminous schists and as veins in what was originally a clay-rich hydrothermal alteration envelope about massive suphide deposits. These carpholites have Fe/(Fe + Mg) ratios of 0.03–0.65 and no significant Mn component. Mg-carpholite + quartz occur in assemblages with chlorite or pyrophyllite, pyrophyllite + kaolinite and pyrophyllite + diaspore. Temperatures of 230–320° C and minimum pressures of 7 kbar are indicated for the Mg–Fe carpholite-bearing rocks. The regional distribution of aragonite and Mg–Fe carpholite parallel to a major zone of dominantly transcurrent movement and oblique to the trend of the subduction complex indicates the high- P /low- T schists owe their rapid uplift and preservation to the vertical component of the transcurrent faulting.  相似文献   

Interlayer and Si content of phengite in HP–LT carpholite-bearing metapelites     

P. Agard  O. Vidal  B. Goffé 《Journal of Metamorphic Geology》2001,19(5):479-495

Phengite occurring along with carpholite±lawsonite and/or chloritoid in HP–LT domains shows not only variable Si–(Mg+Fe) contents, but also variable interlayer contents (IC). To determine whether these chemical variations are coherently related to variation in P–T conditions on a regional scale, c. 100 rock samples were sampled in metapelites metamorphosed at conditions varying from 350 °C, 8 to 12 kbar to 450–500 °C, 18 to 20 kbar (Schistes Lustrés complex, franco‐italian Western Alps). Based on microstructural and habit criteria, four types of phengite were differentiated that are related either to the rock mineralogy (carpholite vs chloritoid bearing samples) or correspond to various generations of phengite occurring in the same rock sample or thin section. Microprobe analyses reveal that each type of phengite is characterized by a specific composition and that phengite associated with carpholite has a lower interlayer content than phengite associated with chloritoid. The successive generations of retrograde phengite overgrowing carpholite point to a large decrease of interlayer content (c. 0.9–0.7 pfu) and (Fe+Mg) content (c. 0.25–0 pfu) with decreasing P–T conditions. This change is best accounted for by a gradual increase of the pyrophyllite component. In contrast, phengite from higher‐temperature, chloritoid‐bearing rock samples shows an almost constant interlayer content (c. 0.9–0.95 pfu) but a larger decrease of (Fe+Mg) content (c. 0.6–0.1 pfu). Hence, (1) the composition of the different phengite generations occurring (metastably) in the same rock sample may be used to retrieve points in P–T loops and (2) the pyrophyllitic substitution in phengite is large at low‐temperature conditions and cannot be ignored. Thermobarometric estimates based on the Si‐content alone will therefore result in pressure over‐estimates. We propose a tentative location of the phengite Si and IC isopleths in P–T space which could allow a direct determination of the P–T conditions in carpholite‐bearing rocks. Especially in some carpholite‐bearing rocks, new thermodynamic models accounting for tschermak and pyrophyllitic substitution are also required prior to making reliable thermobarometric estimates in HP‐LT metapelites.  相似文献   

Metamorphism of the Witwatersrand gold fields: conditions during peak metamorphism     

G.N. PHILLIPS 《Journal of Metamorphic Geology》1987,5(3):307-322

Abstract Pelitic assemblages from all major Witwatersrand gold fields record metamorphic conditions of the greenschist facies, with minimal regional grade changes over at least 200 km strike length. Diagnostic metamorphic assemblages are less common in the volumetrically dominant quartzites, the actively-exploited auriferous conglomerates and some of the regionally persistent metapelitic horizons. Bulk rock composition has been a major control on assemblage development.
Key metapelitic assemblages include pyrophyllite, chloritoid, chlorite and muscovite in each gold field, with less common metamorphic biotite. Accessory minerals are pyrite, tourmaline, rutile and zircon. The abundance of chloritoid and pyrophyllite in thin shaly units, together with their minor, but widespread, distribution in quartzites and conglomerates, indicate that metamorphic temperatures reached 350°C ± 50°C in all the gold fields. Pressures are less-well constrained, 1–2 kbar being inferred. Outside the gold fields, higher grades are indicated by andalusite and kyanite near granitoid domes and later intrusions.
The temperatures during peak metamorphism and the abundance of pyrite provide ideal conditions to (re)mobilize gold and may explain its secondary textural features.  相似文献   

叶蜡石矿产资源及其应用开发研究现状     

姚文君  张培萍  李书法  马丽艳  苏克 《世界地质》2007,26(1):124-129

介绍了叶蜡石在国内外的分布概况、叶蜡石的结构和特性，及其开发利用现状和存在的问题，并提出了相应的解决方法。着重分析了叶蜡石在超细粉体加工、表面改性、高温相变研究、涂料和填料中的应用，以及作为传压介质的研究现状；并在此基础上指出了其今后的发展方向。  相似文献   

福建加良山寿山石的矿物学特征及成因   总被引：2，自引：0，他引：2       下载免费PDF全文

孙旎  崔文元徐湘 《岩石矿物学杂志》2003,22(3):273-278

应用电子探针、化学分析、X射线衍射、红外光谱、拉曼光谱等分析手段对加良山寿山石进行了研究，结果表明其主要组成矿物是叶蜡石，并含有硬水铝石和石英，大部分叶蜡石以2M型为主。该矿区为火山热液矿床，成矿明显分为早、中、晚3个阶段，成矿温度285～405℃，压力小于0．26GPa。  相似文献   

寿宁-福州上侏罗统南园群叶蜡石矿地质特征     

吴资龙 《福建地质》2003,22(3):125-130

寿宁—福州一带蕴藏丰富的叶蜡石矿资源，多产于南园群火山碎屑岩地层中，小溪组地层为最主要赋矿层位，围绕火山机体发育的环状断裂为成矿最有利部位，近矿围岩普遍发育次生石英岩化，围岩蚀变具有明显的水平及垂直分带现象。  相似文献   

寿山叶蜡石矿床中叶蜡石的多型及其转变   总被引：4，自引：1，他引：4  

杨献忠  黄光昭 《福建地质》1993,12(3):172-181

叶蜡石具有1Tc和2M_1两种多型。寿山叶蜡石矿床中的叶蜡石不但具有普遍报道的2M_1型及1Tc与2M_1的混合型,而且具有同类矿床中少见的、但在本区却大量出现的1Tc型。本文对寿山叶蜡石多型变体的X射线衍射特征、镜下特征及化学成分特征作了写实性描述,指出本区叶蜡石存在着2M_1型向1Tc型转变的客观事实,并可能存在二者的中间类型;探讨了叶蜡石多型转变的条件,提出“表生溶液”是实现该转变的主要因素。  相似文献   

我国叶蜡石的差热和红外光谱研究   总被引：5，自引：0，他引：5  

陈大梅  姜泽春等 《矿物学报》1991,11(1):92-96

叶蜡石的吸热反应温度为600－800℃，失重量5％。叶蜡石的红外光谱有两种基本振动形式，在含石英较多的叶蜡石红外谱图中，叶蜡三笺吸收谱带减弱或消失。在叶蜡石加热到1000℃后的X射线粉昌衍射谱图上，出现了莫来三方英石的特征谱线。  相似文献