摘要:
应用热年代学方法,揭示了燕山南缘盘山岩体的热历史与隆升过程。结果表明,盘山岩体的侵位深度约为10km.岩体侵位以后,经历了快速冷却过程,在226.48Ma~204.95Ma期间,岩体温度由520℃冷却至300℃,平均降温速率为10.22℃/Ma.204.95Ma~118Ma期间为盘山岩体的缓缦隆升时期,平均隆升速率约为0.028mm/a,隆升幅度约2.5km.118Ma~96Ma为盘山岩体较快速隆升时期,隆升速率为0.035mm/a,隆升幅度约0.77km.96Ma~35Ma为盘山岩体与盘山山脉的快速隆升时期,隆升速率约为0.115mm/a,隆升总幅度达7km.35Ma以来,盘山岩体的隆升速率很小,仅约0.014mm/a,隆升幅度约为0.5km.盘山周缘环状构造系统的形成时代略早于226.48Ma,盘山南缘边界正断层的活动时代为中生代末~始新世。
Abstract:
The thermal history and uplifting of the Pangshan pluton at the southern margin of the Yanshan orogenic belt were studied in detail by thermochronological dating.It was revealed that the Panshan pluton was intruded at a depth of about 10km before 226.48Ma. This was followed by a rapid cooling at a rate of 10.22℃/Ma during 226.48~204.95 Ma subsequently, it was uplifted 2.5km in the period of 204.95~118Ma at a rate of 0.028mm/a, 1.33km in the period of 118~80Ma at a rate 0.035mm/a, approximately 7km during 80~35 Ma at a rate of 0.08 mm/a, and about 0.5km since 35Ma at a rate of 0.014mm/a.The ring structures system surrounding the pluton formed a little earlier than 226.48Ma, and the boundary normal fault between it and the North China Basin was formed and became active mainly during 80~35Ma.
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