论文部分内容阅读
铜陵狮子山地区中酸性侵入岩锆石 SHRIMP U-Pb 定年结果表明,白茫山辉石二长闪长岩、鸡冠山和大团山石英二长闪长岩以及胡村花岗闪长岩的年龄分别为:138.21±0.82Ma、139.9±1.1Ma、139.3±1.2Ma 和140.9±1.2Ma。岩浆侵位顺序为花岗闪长岩→石英二长闪长岩→辉石二长闪长岩。根据锆石 SHRIMP U-Pb 年龄变化范围,推测该区岩浆活动持续的时间约为15Ma,且岩浆属脉动式多次侵位,后期岩浆侵位的热使早期岩体中已结晶的锆石发生熔解、重结晶,形成新的锆石。地下深部岩浆活动频繁,形成了多级岩浆房,使得本区的莫霍面界线不明显。
The SHRIMP U-Pb dating of the intermediate-acid intrusive rocks in the Shizishan area of Tongling shows that the ages of the Baomengxuan diphosgene, the Jiguanshan and the Daquanshan quartz monzodiorite and the Hucun granodiorite Respectively: 138.21 ± 0.82Ma, 139.9 ± 1.1Ma, 139.3 ± 1.2Ma and 140.9 ± 1.2Ma. The sequence of magma emplacement is granodiorite → quartz monzodiorite → pyroxene diorite. Based on the SHRIMP U-Pb age range of zircons, it is presumed that the duration of magmatic activity in this area is about 15Ma, and the magma is pulsatile and multiple emplacement. The heat of magma emplacement in the later period led to the occurrence of crystallized zircon in early rock mass Melting, recrystallization, the formation of new zircon. Deep underground magmatic activity is frequent, forming a multi-level magmatic chamber, making the area of Moho surface boundary is not obvious.