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铜陵矿集区燕山期中酸性侵入岩由橄榄玄粗质系列和高钾钙碱性系列岩石组成,两者的岩石化学和地球化学特征存在差异,相互间不存在岩浆分异演化关系。稀土和微量元素以及O、Pb、Sr、Nd同位素研究表明,高钾钙碱性系列侵入岩的原始岩浆以下地壳深变质岩部分熔融岩浆为主,在有幔源玄武质岩浆注入的情况下先于橄榄玄粗质系列岩浆侵位形成;起源于富集地幔的碱性玄武岩与有限的地壳物质发生同化混染并通过结晶分异作用(AFC)形成了橄榄玄粗质系列侵入岩。下地壳或岩石圈地幔拆沉继而环流热幔上涌是本区侵入岩形成的直接起因;同时,侵入岩浆的强烈活动也是本区构造环境由挤压向伸展转换的标志。
The intermediate-acid intrusive rocks of the Yanshanian Period in the Tongling Ore Concentration Area consist of Oligocene-rich series and high-K calc-alkaline series of rocks. There is a difference in petrochemical and geochemical characteristics between the two rocks. There is no mutual differentiation between magmas. REE, trace elements and O, Pb, Sr and Nd isotopes indicate that the main magmas in the high-K calc-alkaline intrusive rocks are mainly composed of partially molten magmas of crustal deep metamorphic rocks. In the case of mantle-derived basaltic magma Formed in the Oligocene series of magmatic emplacements; alkaline basalts enriched in the mantle are assimilated and mixed with limited crustal material and crystallized into a series of Oligocene intrusive rocks by means of crystallization differentiation (AFC). In the lower crust or lithosphere, the mantle subsidence followed by the upwelling of hot mantle over the circulation is the direct cause of the formation of intrusive rocks in this area. At the same time, the intense activity of intruded magma is also a sign that the tectonic environment in this area changes from extrusion to extension.