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甘肃省铜矿床主要类型及其找矿潜力分析 总被引:1,自引:0,他引:1
通过对甘肃铜矿资源现状的分析以及对主要铜矿类型特征的总结,结合铜矿形成的地质背景和时空分布规律,对我省找矿潜力作出合理评价,并提出了找矿方向。研究表明,甘肃找矿的第一主攻类型为火山岩型铜矿,其次为硫化铜镍型;主攻地区为北祁连和碧口地区,其次为北山和龙首山。 相似文献
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阿拉伯地盾主要是由晚元古宙火山-沉积岩系组成,岩系为大规模同时代的花岗岩类岩基和深成岩所侵入。这些岩石保存很完整,基本上能提供该区从9亿年以前至寒武纪阶段地壳演化的连续记录,成为解决阿拉伯地壳演化过程中古环境的一个关键。该火山—沉积岩系与现代岛弧岩系的相似性首先被Jackaman所注意到,然后他以Green—wood等人提出的地壳演化模式为基础,认为地盾南部的成因可看作是由早期拉斑玄武 相似文献
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Widespread in West Qinling are intermediate-acid intrusive rocks, which cover 85% of the total area and involve five geological periods: (1) Caledonian (457---408 m.y.), (2)Variscan (367--278m.y.), (3) Indosinian (231--190m.y.), (4) Yenshanian (186--107m.y.), and (5) Himalayan, with Indosinian and Yenshanian granitic rocks being dominant. The bulk petrochemical composition of these intermediateacid rocks is: SiO2 64.91,TiO2 0.5, Fe2O5 1.19, FeO 3.07, Mn 0.08, MgO 2.38, CaO 3.52, Na2O 3.40, K2O 3.38 and P2O5 0.16, similar to that of granodiorite in China. According to M. A. Peacock‘s classlfication, the intermediate-acid rocks in this region, for the most part, belong to the calci-alkalic series and only a part of them (e.g. Yenshanian) to the alkali-lime series. As for these rocks, two genetic types can be distinguished: remelting-metasomatic granitic rocks (Rb/Sr 0.73---4.2, K/Rb 104--207, K/St 146---463; the principal components including W, Sn, Ta, Pb, Zn, U, Th, Zr, Y, Yb, Nb, La, Rb, etc. ) and upper mantle remelting-magmatic granitic rocks consisting mainly of granodiorite and quartz diorite (Rb/Sr 0.05--0.6, K/Rb 200--726 (the maximum 1000.7), K/St 10--120 (the maximum 152); Cu, As, Mo, Fe, Cr, Ni, Co, Mn, Ti, etc. as the major components). 相似文献
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关于西秦岭中生代花岗岩类的时代期次问题的讨论 总被引:2,自引:0,他引:2
Based on geological observation and isotopic age data, a continuous cycle of granite iatrnsion from Early-Middle Triassic to Cretaceous has been demonstrated for the Mesozoic granitic bodies in western Qinling Range. Six periods can be further recognized within this cycle, i.e., (Ⅰ) Early-Middle Triassic (240--205 my); (Ⅱ) Late Triassic (205-185 my) ; (Ⅲ) Early Jurassic (185--170 my) ; (IV) Middle-Late Jnrassic (170--140my); (V) Early Cretaceous (140--100my); and (Ⅵ) Late Cretaceous( 100--70 my). 相似文献
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引言太古代地壳一般由下列几个单元或其中之一所组成:a)大面积的花岗岩一片麻岩区,b)绿岩带及与其伴生的花岗质深成岩,c)麻粒岩带。这几个单元各自的地质动力学含义及其相互间的关系,至今仍然是个争论不休的问题,而且对太古代地壳演化的成因模式也没有一致意见(Windley,1977)。本文论述芬兰拉普兰太古界中有三个基本组成单元产出的一个较小也区(约55000平方公里)。目的是概述这些岩石类型的分布,讨论它们的变质和构造演化,进而提出一 相似文献