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11.
Field investigation and laboratory work reveal that inhomogeneity of the deformation of the Xiannushan fault is mainly characterized by lateral zonation, longitudinal segmentation and downward stratification. Based on these results, a 3-D deformational structure model of the fault was established and its geometrical and kinematic characteristics in two main deformational stages i.e. the main Yanshanian and Himalayan were discussed. The directions of principal and the differential stresses in these two stages were determined by using conjugate joints, striations of fault planes and microstructures of the fault zone. The direction of σI is N-S in direction with differential stresses of 150-250 MPa in the Yanshanian, and N70E with a differential stress ranging from 80-120 MPa in the Himalayan.  相似文献   
12.
江苏句容早三叠世鱼类化石之发现及其意义   总被引:1,自引:0,他引:1  
记述了江苏句容下三叠统青龙组下三叠统青龙组下部地层中发现的软骨硬鳞鱼类一新种-江苏裂齿鱼和半椎鱼类一新种-句容鳞齿鱼化石,并讨论了其分类特征、生存环境及化石埋藏状况。  相似文献   
13.
蒸气爆发、蒸发岩浆爆发起因于岩浆与外部水的相互作用所形成的基底涌流堆积物。近代火山学资料表明都是一些尚未固结的松散物,而在古火山岩区则是一套成层性极大的火山碎屑岩。着重论述粤东中生代火山岩区基底涌流相地层学、岩石学特征,指出该相岩石具有沉积碎屑岩和火山碎屑岩的双重特点,但其岩石命名应与火山碎屑流相相对应。该相岩石所具多种组分特征、结构构造和岩石类型,可作为在古火山岩区识别这类岩石的重要依据。  相似文献   
14.
辽宁弓长岭含铁建造年代学研究   总被引:2,自引:0,他引:2  
用热离子质谱计双带源蒸发—沉积测定单个锆石晶体年龄的方法对弓长岭含铁建造中黑云变粒岩、混合岩化浅粒岩和石英岩中的锆石作了测定,获得了2.60—2.54 Ga,3.36—2.62 Ga和3.53—3.08 Ga等年龄数据。结合已有的研究资料可以认为,黑云变粒岩的原岩来自2.7 Ga左右的中酸性火山物质,浅粒岩和石英岩的原岩来自3.0 Ga以上的花岗质地壳物质;含铁建造形成于陆壳基底之上,形成时间约2.7 Ga,并于2.5—2.7 Ga之间发生首次变质作用。  相似文献   
15.
西藏罗布莎蛇绿岩铬铁矿中金刚石的研究   总被引:27,自引:3,他引:27  
在西藏罗布莎豆荚状铬铁矿中发现过金刚石,但迄今仍有人因为自己所取的小试样中没有分离出金刚石而否定罗布莎等地金刚石的存在。由于金刚石涉及西藏雅鲁藏布江缝合线和蛇绿岩、铬铁矿成因等问题,笔者重新在罗布莎铬铁矿中取样,经过选矿,又在1500kg样品中选出了25粒金刚石和近70种伴生矿物。这就表明西藏金刚石是的确存在的,而且它和蛇绿岩的铬铁矿同是深部成因的产物。  相似文献   
16.
A New Intergrowth Consisting of FeO and SiO_2 Phases from Lower Mantle   总被引:2,自引:0,他引:2  
1. IntroductionIn order to confirm the presence or absence of diamonds in the Luobusa ophiolitic chromitite in Tibet, about 1500 kg chromitite sample was collected for separating its associated minerals, in which diamond, moissanite, octahedral pseudomorphic serpentine and chlorite, native silicon, native chromium, some alloys and other minerals were found. A wide variety of minerals, including about 70-80 types of mantle minerals from the Luobusa ophiolite, were identified by energy dispersi…  相似文献   
17.
The Gacun Kuroko-type deposit, Southwestern China, is hosted in rhyolitic rocks associated with the underlying mafic rocks occurred in the ~1000 m deep fault-hounded basin within the intra-arc rifting zone which formed on the Triassic Yidun island-arc. Two vertically separated alteration systems are recognized: one is conformable or semiconformable alteration zone developed in ~150 m thick mafic unit 1-1.5 km below the massive sulfde orehody; the other is discordant alteration pipe directly surrounded around stockwork ore within rhyolitic unit. The lower conformable alteration zone extending for several kilometers along strike is characterized by silicification and epidotization which result in the development of quartz vein and quartz-epidote vein systems in mafic lava flows and replacement of primary minerals and groundmass in spilitized mafic volcanics and dikes by quartz, epidote-group minerals and sodic plagiocluse. Sulfides often occur in the vein system and altered mafic volcanics. Quartz solubi  相似文献   
18.
A series of thermal-structural-gneiss domes (briefly TSG domes) are developed in the Chinese Altaides. Sericite-chlorite zone, biotite zone, garnet zone, staurolite zone, kyanite (andalusite)zone, sillimanite- cordierite (sillimanite-garnet)zone, migmatite zone and migmatic granite- gneiss field are developed from the low-grade metamorphic area to the centre of the TSG domes. The succession of the formation and evolution of the progressive metamorphic zone, migmatite zone and migmatic granite-gneiss corresponds to the spatial sequence from the outer part to the centre of the TSG domes. The peak temperature of the metamorphism and granitization increases progressively from 400℃ to 800℃ while the pressure decreases progressively from 1.05 GPa to 0.10 GPa from the biotite zone to the migmatic granite-gneiss field. The metamorphism of the erogenic belt may be described by the pressure-temperature-space-time model (PTst). In the main episode of orogeny, the deep heat flow and structural flow upsurged along  相似文献   
19.
煤基石墨的喇曼光谱学研究   总被引:1,自引:0,他引:1  
陈宣华  郑辙 《矿物学报》1993,13(4):313-318
煤体经热变质作用形成的石墨叫煤基石墨。本文研究了煤基石墨的一级和二级喇光谱。作者认为,石墨及有关的碳质物质的一级喇曼光谱是由层内振动激发的,反映了它们作为二维晶格的完整性程度。煤基石墨中存在的层内结构缺陷分为两种,一是煤中特有的,在石墨化过程中逐渐消失,另一是由研磨(剪切应力)作用带入的,可能与构造应力作用有关,石墨化过程和剪切应力作用过程是效果近于相反的两过程,而石墨的二级喇曼光谱则可揭示其作为  相似文献   
20.
徐珏 Moh  GH 《地质论评》1993,39(3):231-235
作者通过T1—In-S三元系实验研究,在300℃等温面上发现4个三元固溶体相和2个三元相。4个三元固溶体相的成分变化范围分别是:(Ⅰ)T1_(2C)InS_(16)-T1_(40)In_3S_(33);(Ⅱ)T1_4InS_5—T1_4InS_4;(Ⅲ)T1_8In_2S_7—T1_(15)In_3S_(11)和(Ⅳ)T1_2In_2S_5。2个三元相的成分分别是T1_3InS_3和T1_2In_2S_3。这些相之间的关系清楚地示于T1-In-S相图中。此外,在600℃时合成了三元相T1In_2S_3,并对前人的实验研究进行了补充和修正。  相似文献   
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