新疆阿尔泰铁热克提岩体热历史的磷灰石裂变径迹法研究

Thermal History of the Tiereketi Batholith in Altay Mountains,Northern Xinjiang:Evidence from Apatite Fission Track Analysis

通过对新疆阿尔泰铁热克提岩体 4个磷灰石裂变径迹样品分析研究表明 ,具有 3个阶段的热演化模式 :①大约 12 0Ma之前 ,温度为 10 5～ 130℃或 90～ 12 0℃ ,属于较高温稳定期 ;② 6 0～ 12 0Ma,温度为 90～ 12 0℃或 2 0～ 6 5℃ ,系快速冷却与隆升期 ;③ 6 0Ma以来为 2 0～ 6 5℃或 12～ 18℃ ,属低温稳定期。第 2阶段 (6 0～ 90Ma期间 ) ,冷却速率为 2 .5～ 3.2 3℃ /Ma ,相当于抬升速率为 83.3～ 10 7.7m/Ma。 6 0～ 12 0Ma的快速隆升作用以及 80 .4～ 91.9Ma的裂变径迹年龄 ,证实燕山晚期发生过新的陆内挤压造山活动。

Fission track analysies of 4 apatite samples from Tiereketi granite batholith in the Altay Mountains of northern Xinjiang show three stages of thermal history. Before 120 Ma,the temperatures were 105～130℃ to 90～120 ℃;during 60～120 Ma,the temperatures ranged from 90～120 ℃to 20～65 ℃;since 60 Ma,the temperatures have varied in the range of 20～65 ℃ to 12～18 ℃.The 60～90 Ma period was a rapid cooling and uplifting stage,with the cooling rate being 2.5～3.23 ℃/Ma and uplifting rate 3.3～107.7 m/Ma. The rapid uplift during the 60～120 Ma and the apatite fission track ages of 80.4～91.9 Ma indicate that there once existed an intracontinental compressional orogeny in about 60～120 Ma.