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深处岩浆分异与某地花岗伟晶岩的形成 总被引：1，自引：0，他引：1
Two stages of intrusion have been recognized for Paleozoic pegmatites in this district. The pegmatites occur as several thousands of dikes, with 84 per cent of them distributed within three “thickly concentrated areas”. Similar horizontal zoning, i.e.,from the parental granite outwards the pegmatites vary from type K through type Na to type Li, is observed within these “thickly concentrated areas”, which consist of pegmatites of different stages. Temporally, the pegmatites also evolve in the same sequence of types K-Na-Li, with a series of mineralized dikes produced during this process. The occurrence of this phenomenan is not accidental but a strong indication of deepseated magmatic differentiation. In nature, not all granitic magmatism can bring about pegatite emplacement,nor all the pegmatite dikes are of the same petrological character. These differences indicate that deep-seated magmatic differentiation must be controlled by some factors.It‘s development is believed to be dependent largely on the amounts of both parental and residual magmas and on the extent to which the pressure at their source region has been lowered by the intrusion of granite. The constant movement of the crust results in the continuous upward migration of differentiated magma, so as to promote the differentiation to a greater extent, thereby providing new source materials for subsequent intrusive activity. Such a continuous movement of opposites leads to the formation of a complete series of pegmatites, i.e., from biotite-microcline pegmatite to lepidolite-albite pegmatite, giving rise to the “thickly concentrated areas” as well as a series of mineralized veins. 相似文献
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陈西京 《地球科学与环境学报》1981,(2)
本文研究了某地含铯榴石伟晶岩的分布规律及特征后,认为铯在伟晶岩浆晚期的富集,是由于挥发组分的集中、岩脉局部膨大、致密围岩的作用等条件而引起的。因此,分异晚期形成的锂云母微斜长石纳长石伟晶岩、岩脉的膨大部位、致密块状围岩是寻找铯榴石的重要标志。 相似文献
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论东秦岭某地花岗伟晶岩的分布规律 总被引：1，自引：0，他引：1
陈西京 《地球科学与环境学报》1982,(1)
东秦岭某地花岗伟晶岩主要分布在同源花岗岩一侧,形成密集区。这种密集区受褶皱构造所控制,而伟晶岩脉的分布主要又受褶皱过程中所派生的裂隙构造所控制。伟晶岩浆的侵入作用是在构造运动作用下,脉动式发展,侵位后呈明显的水平分带规律。 相似文献
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云南地矿局坚持以地质-找矿为中心,深化经济运行机制改革,优化队伍结构,确保地质勘查经费的有效投入,提前两年超额完成了部下达的“八五”找矿任务.1994年地矿部和云南省政府联合表彰奖励了云南局三个取得重大突破的找矿项目,有三个地勘单位被授予“找矿有功 相似文献
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