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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
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
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吉林省东部石炭-二叠系伊利石的成因标志 总被引:1,自引:0,他引:1
吉林东部石炭-二叠系主要是一套泥质岩石, 其详细深入的矿物学工作尚不多见。利用JSM-6700F场发射电镜及INCA能谱仪,研究了伊利石的显微形貌和微区成分。采用D/max-2500 X-射线衍射仪,研究了伊利石的结晶度、多型和b0值。结果表明:研究区伊利石结晶度变化于0.26~0.77,平均值为0.44;伊利石(白云母)多型有3种类型,分别为1Md型、1Md+2M1混合型和2M1型;伊利石(白云母)b0值为8.996~9.045,平均值为9.007Å。石炭系伊利石结晶度变化于0.26~0.50,平均值为0.35,主要呈2M1多型,b0平均值为9.011Å,主要是低级近变质带的产物;二叠系伊利石结晶度变化于0.26~0.50,平均值为0.42,主要为1Md+2M1混合型多型,b0平均值为9.004Å,主要为晚期成岩带的产物。 相似文献
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BUI Hoang B NGO Xuan Thanh Yungoo SONG Tetsumaru ITAYA Koshi YAGI KHUONG The Hung NGUYEN Tien Dung 《《地质学报》英文版》2016,90(5):1653-1663
Constraining the timing of fault zone formation is fundamentally important in terms of geotectonics to understand structural evolution and brittle fault processes.This paper presents the first authigenic illite K-Ar age data from fault gouge samples collected from the Red River Shear Zone at Lao Cai province,Vietnam.The fault gouge samples were separated into three grain-size fractions(0.1 μm,0.1-0.4 μm and 0.4-1.0 μm).The results show that the K-Ar age values decrease from coarser to finer grain fractions(24.1 to 19.2 Ma),suggesting enrichment in finer fraction of morerecently grown authigenic illites.The timing of the fault movement are the lower intercept ages at 0%detrital illite(19.2 ± 0.92 Ma and 19.4 ± 0.49 Ma).In combination with previous geochronological data,this result indicates that the metamorphism of the Day Nui Con Voi(DNCV) metamorphic complex took place before ca.26.8 Ma.At about 26.8 Ma-25 Ma,the fault strongly acted to cause the rapid exhumation of the rocks along the Red River-Ailoa Shan Fault Zone(RR-ASFZ).During brittle deformation,the DNCV slowly uplifted,implying weak movement of the fault.This brittle deformation might have lasted for ca.5 Ma. 相似文献
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SinceJacobsonandWebb (194 7)firstlyfoundthenigeriteinNigeria ,mineralogistshavefounditinmanycountriessuchasRussia (EastSiberia ,195 8) ,China(Hunan ,196 3) ,Portugal (196 5 ) ,Australia (1976 )andsoon .Greyetal.(1979)determinedaccuratelythecrystalstructureofnigerite (2 4R) .In 1988,Chenfoundakindofendmembermineralofnigerite ,whichisMg riched .ByapprovingofCommissiononNewMineralsandMineralNames (CNMMN) ,thismineralwasnamedpengzhizhongite .Inthepast ,somemineralogistsdidnotfurtherdis t… 相似文献