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铜陵地区中酸性侵入岩及其岩石包体的成因与Fe, Cu成矿作用和长江中下游岩石圈动力学演化关系密切. 本文以铜陵地区代表性的中生代中酸性侵入岩铜官山岩体及其岩石包体为研究对象, 进行了仔细的岩相学研究、矿物化学电子探针成分分析和LA-ICPMS锆石U-Pb同位素定年. 铜官山角闪 石-辉石堆积岩包体中辉石、角闪石矿物的化学成分与寄主岩中相应矿物的化学成分呈明显的线性变化, 但Al含量高, 是岩浆侵位前结晶的产物. 铜官山寄主岩及微粒闪长岩包体中辉石、角闪石矿物化学成分相似, 说明它们有密切的成因联系, 形成压力相仿. 铜官山石英闪长岩中锆石颗粒的定年结果表明该岩体的结晶年龄为137.5 1.1 Ma, 与以往不同方法的定年结果十分一致, 但本次锆石U-Pb同位素LA-ICPMS定年同时揭示了晚太古代残留锆石的存在, 证实该地区中生代岩浆作用有古老下地壳物质的参与. 定年结果还表明微粒闪长岩包体的结晶年龄为137.52.4 Ma, 与寄主岩浆的结晶年龄完全一致. 此外, 本文还结合以往的Sr-Nd-Pb同位素资料, 讨论了铜官山石英闪长岩及其包体的成因.
The genesis of the intermediate-acid intrusive rock and its rock inclusions in Tongling area is closely related to the Fe and Cu mineralization and the evolution of lithospheric dynamics in the middle and lower reaches of the Yangtze River.Based on the Mesozoic intermediate-acidic intrusive rocks, The rock inclusions were studied, and meticulous petrography studies, mineral chemical electron probe composition analysis and LA-ICPMS zircon U-Pb zircon dating were performed. The chemical composition of pyroxene and hornblende minerals show a linear change with the chemical composition of the corresponding minerals in the host rocks, but the Al content is high, which is the product of crystallization before the emplacement of magma.The Tongguanshan host rock and the microparticle diorite pack The pyroxene and hornblende minerals in the body are similar in chemical composition, indicating that they are closely related to each other in formation pressure.The dating of zircon grains in Tonggoushan quartz diorite shows that the rock age is 137.5 1.1 Ma , Which is consistent with the dating results of different methods in the past. However, the dating of zircon U-Pb isotope LA-ICPMS reveals the existence of Late Archean remnant zircon, confirming that the Mesozoic magmatism in the area is ancient The results also show that the crystallization age of the microparticle diorite inclusions is 137.52.4 Ma, which is completely consistent with the host rock’s age of crystallization.In addition, based on the previous Sr-Nd-Pb isotope data, Causes of Guanshan quartz diorite and its inclusions.