共查询到20条相似文献,搜索用时 93 毫秒
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宝兴沟金矿床是位于上黑龙江成矿带上的大型岩金矿床。在充分收集矿区已有资料的基础上,结合矿区钻孔样品及地球化学剖面数据,对矿床地球化学特征进行了研究。研究表明,二十二站组地层成矿元素含量普遍高于克拉克值,且元素变异系数较大,有利于发生迁移,矿体两侧围岩中存在成矿元素向矿体迁移而产生的低值区。地层、构造、岩浆岩是主要的控矿因素,二十二站组地层为矿源层,北东向断裂及其次级断裂控制了矿体的形态和产状,(石英)闪长岩脉、闪长玢岩脉与成矿关系密切,二十二站组地层、北东向构造及岩脉同时存在是寻找金矿体的理想部位。 相似文献
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甘肃小独山西钨矿床成因探讨 总被引:2,自引:0,他引:2
小独山西钨矿床是近年来新发现的大型钨矿床,笔者从地层、构造、岩浆岩、蚀变作用等成矿条件入手,对该矿床的成因进行了探讨。该区地层、构造、岩浆岩条件的完美耦合是该矿床形成的根本原因。矿区下二叠统红柳河组各岩性层中钨元素丰度值高,为该矿床的形成创造了物质条件;矿区极其发育的断裂裂隙系统,为后期成矿热液的运移、物质交换、成矿元素的沉淀富集提供了通道及储存空间;燕山早期的岩浆活动,在为成矿提供热源、物源的同时,使得早期的断裂裂隙系统再次活动,为成矿热液的运移、物质交换、成矿元素的沉淀富集开辟了更为广阔的通道及储存空间;燕山早期岩浆期后热液沿着前期形成的断裂裂隙充填交代,在高温阶段形成石英脉脉型黑钨矿,随着温度的逐渐降低,形成石英脉脉型白钨矿;原生矿床形成后,经过长期的表生作用,进一步次生富集形成沿沟谷产出的钨砂矿。小独山西钨矿床是与酸性岩浆活动有关的充填交代式石英细脉带型(黑)白钨矿矿床。寻找成矿热液运移通道及其方向,将成为今后该区找矿工作的重点。 相似文献
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镇安西部棋盘沟矿区内的钨矿体主要为石英脉型钨矿,产出于矿区内近SN向断裂中,矿石中金属矿物以白钨矿为主,矿体规模大且品位高,但矿区内未见有岩浆岩体出露,因此明确其成矿流体来源是理解矿床成因的关键。为了探究成矿流体特征,分析了主成矿阶段形成的白钨矿与石英颗粒中主要发育的气液两相包裹体,结果显示包裹体均一温度介于291.4~423.7 ℃之间,热液盐度[w(NaCl)]为5.1%~7.7%,流体的密度范围为0.52~1.08 g/cm3。这表明矿区成矿流体属于中高温、低盐度流体,与典型热液钨矿流体相似,H、O同位素测定结果显示其主要来源为岩浆水,S同位素落入岩浆岩S同位素组成范围内,反映矿区钨矿来源于岩浆热液。与周边矿区似层状钨矿流体包裹体相比,棋盘沟矿区成矿流体均一温度明显较高,说明近SN向构造是成矿热液运移的主要通道,在成矿流体运移过程中,顺着该区NNE向断裂裂隙上升,形成石英脉型白钨矿。随着成矿热液温度持续降低,矿液沿层间裂隙灌入形成似层状型白钨矿。 相似文献
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《南方金属》2021,(2)
包金山Au-Sb-W矿床位于湘中成矿区的东北部。该矿床中W以白钨矿的形式产出,产于石英脉中。白钨矿的形成分为两个阶段。第一阶段白钨矿产于乳白色石英脉脉壁两侧,呈对称带状;第二阶段白钨矿以团块状产于烟灰色石英脉中及脉壁。两期白钨矿的晶体化学式分别为Ca_(0.890)[W_(1.035)O_4]和Ca_(0.886)[W_(1.037)O_4]。微量元素种类相似,以类质同象的形式存在。通过分析认为,岩体和地层共同为矿床白钨矿提供了成矿物质来源,最终与围岩中Ca结合沉淀,形成白钨矿。在这一过程中,断裂构造连同地层一起起到了控制作用,岩浆活动为成矿提供了能量。 相似文献
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倪志安 《Canadian Metallurgical Quarterly》2011,23(3)
马克思主义唯物论是一种物本主义形态的唯物论,还是一种超越物本主义形态、从实践理解世界的本质相关问题的实践的唯物主义的唯物论?这是一个我们必须搞清楚的有关马克思主义唯物论的本质规定性和精神实质的重大问题.在考察物本主义的唯物论及其思维方式的局限性的基础上,揭示了马克思主义唯物论是现代的、实践的唯物主义,并重点研讨了马克思主义唯物论关于从实践理解世界的物质性和自然世界的先在性的原理,以期为马克思主义唯物论进一步阐明人类世界的实践性原理奠定基础. 相似文献
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D. N. Reznikov 《Metallurgist》1962,6(12):535-537
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The data are presented on changes in the rat arcuate nuclear neuron ultrastructure after using cyproheptadine (peritol, Egyt Pharmaceutical Works, Hungary) in a water suspension at a dose of 20 mg/kg once daily during 7 successive days and twice a day within 10 days. It was shown that cyproheptadine decreases the functional activity of the arcuate nuclear neurons, depending on the total amount of the drug used. Cyproheptadine-induced inhibition of the forming neurohormone release from neurons is likely to be one of the mechanisms of its therapeutic effect in Itsenko-Cushing's disease. 相似文献
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Vasomotor responses from the nasal mucosa and tongue, and contractions of the nictitating membrane, were recorded on stimulation of the cervical sympathetic or internal carotid nerves. Preganglionic sympathetic nerve fibres which elicited a membrane response possessed a lower threshold than those which evoked nasal vasoconstriction, while the latter displayed a lower threshold than fibres which evoked tongue vasoconstriction. The sympathetic vasodilator fibres to the tongue whose activity was revealed after alpha-receptor blockade, had a similar threshold to the vasoconstrictor fibres. Membrane contraction, nasal vasoconstriction and occasionally tongue vasoconstriction could be evoked by stimulating the internal carotid nerve. The postganglionic fibres innervating the nasal mucosa had a similar threshold to those of the nictitating membrane, which may indicate that there are small myelinated fibres innervating the mucosa. The preganglionic compound nerve action potential had four major components, S1-S4. S1, S2 and usually S3 fibres were associated with membrane contraction; S2, S3 and sometimes S1 fibres were associated with nasal vasoconstriction; and S3, usually S2 and occasionally S1 fibres were associated with vasoconstriction in the tongue. It is concluded that each of these three groups of nerve fibres, but not S4 fibres, may include fibres associated functionally with the three effectors. There was a considerable difference between the relative amplitude of the responses of the three effectors elicited by stimulation of the cervical sympathetic nerve at frequencies between 0.2 and 2 Hz. Vasoconstrictor responses were relatively larger than membrane contractions suggesting differences in the mechanisms of neurotransmission at the neuroeffector junctions. 相似文献
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