Abstract:

⁴⁰Ar-³⁹Ar analyses and MDD(multiple diffusion domain)model treatements were performed for 9 K-feldspar samples.They were collected from gneiss and mylonite of North Jiangsu-Jiaonan-Dabie tectonic melange belt and Tancheng-Lujiang fault zone.The thermal evolution history exhibits five fast ccoling stages found in these samples.In relation with their possible tectonic implications a recovery process after the collision of the North China plate with the Yangtze plate is suggested here.

Key words: Metamorphic belt, Themal history, Geological, Geological age determina-tion, MDD moddel

摘要：

对采自苏北-胶南-大别高压变质构造混杂岩带的片麻岩、糜棱岩和郯庐断裂带上的片麻岩中9个钾长石进行了⁴⁰Ar-³⁹Ar年龄测定和多重扩散域(MDD)模式处理,9个样品的热演化史表明上述地区存在5个不同的快速冷却时段,并就其可能的构造含义,提出了华北与扬子板块碰撞后的折返历史过程。

关键词: 变质带, 热历史, 地质年代测定, MDD模式