佳木斯地块花岗质片麻岩的独居石年龄及其地质意义  

Monazite Ages and Its Geological Significance of Granitoid Gneiss in the Jiamusi Massif

作　　者：温泉波[1] 刘永江[1] 李伟民[1] 韩国卿[1] 丁凌[1] 

机构地区：[1]吉林大学地球科学学院,长春130026

出　　处：《吉林大学学报（地球科学版）》2008年第2期187-193,共7页Journal of Jilin University：Earth Science Edition

基　　金：国家油气专项(XQ-2004-07)

摘　　要：依据电子探针独居石Th-U-Pb化学法(CHIME)对分布于佳木斯地块北部花岗质片麻岩进行定年,其中独居石415 Ma年龄值报道了佳木斯地块北部存在志留纪晚期的岩浆热事件,(494.35±23.6)Ma、(506.96±52.20)Ma(、481.04±23.19)Ma的独居石年龄值表明,佳木斯地块北部存在500 Ma(晚泛非期)的高级变质事件,结合南部的锆石SHRIMP年龄数据,认为整个佳木斯地块都存在500 Ma(晚泛非期)的高级变质事件。该时期佳木斯地块和松嫩地块可能已经拼贴到一起,共同遭受了500 Ma(晚泛非期)变质事件的影响。The granitoid gneisses in the northern Jiamusi massif is suitable for dating by Chemical Th - U - Total Pb isochron method （CHIME）. Monazite dating of 415 Ma indicates a magmato-thermal event in the Late Silurian. The dating results of （494. 36 ± 23. 6 ）Ma, （506. 96 ± 52. 20）Ma and （481.04±23.19）Ma provide the conclusive evidence for a 500 Ma Late Pan-African high-grade metamorphic event in the northern Jiamusi massif. Combined with the SHRIMP U - Pb zircon dating results from the southern Jiamusi massif, it is concluded that the entire Jiamusi massif has undergone a 500 Ma high- grade metamorphic event. The Jiamusi massif and Songnen massif could have amalgamated and linked together before and were affected variously by metamorphic event during 500 Ma.

关 键 词：佳木斯地块 花岗质片麻岩 独居石(CHIME法)定年 

分 类 号：P542.2[天文地球—构造地质学] P588.3[天文地球—地质学]