摘要
对黄陵花岗岩基英云闪长岩的黑云母、角闪石单矿物进行阶段加热法^(40)Ar-^(39)Ar定年,获得黑云母和角闪石坪年龄分别为837.3±4.2～838.7±4.0Ma和844.0±4.2Ma,属于晋宁运动晚期事件。结合黄陵花岗岩基已有的年龄资料作出英云闪长岩的冷却曲线,显示英云闪长岩经历了850Ma～800Ma的一个岩浆活动时期,并在840Ma～830Ma之间存在一个快速冷却的过程,指示当时处于一种伸展的构造背景下,这一事件可能与位于华南的约825Ma的地幔柱上隆导致的Rodinia超级大陆的裂解事件相互响应,之后岩体经历了一个长期的演化过程,到≈800Ma该期岩浆活动基本结束。
Biotite and amphibole samples from tonalite of Huangling granitoids give ^40 Ar-^39 Ar plateau ages of 837.3 ± 4.2 - 838.7 ± 4.0Ma and 844.0 ± 4.2Ma after the incremental heating, respectively, which is the late stage of Jinning movement. Combined with the age data of Huangling granitoids, we get the cooling curve of the tonalite, which reveals a magma activity period of 850Ma - 800Ma, the results also show a fast cooling process during 840Ma - 830Ma and indicate a extending tectonic background, which may be related to the rifting of Rodinia supercontinent caused by the uplift of the mantle plume existed in South China, about 825Ma ago, After a long evolution stage the magma activity disappeared at≈800Ma.
出处
《岩石学报》
SCIE
EI
CAS
CSCD
北大核心
2007年第5期1067-1074,共8页
Acta Petrologica Sinica
基金
国家自然科学基金重点项目(40032010B)
