【摘要】 礼乐盆地位于南海海域南部,是一个形成于中新生代的叠合盆地,长期以来缺乏构造热演化方面研究。本文在认识礼乐盆地构造演化的基础上,选用盆地内地震测线(L2剖面),应用二维横向不均匀拉张模型对礼乐盆地构造热演化史进行了模拟研究。模拟结果揭示了盆地在新生代的构造热演化特征:(1)盆地经历了两次连续的拉张过程,第一期拉张幅度较小,拉张系数在1.05左右,第二次拉张程度较第一次拉张强烈,深水地区拉张系数达到1.3;(2)礼乐盆地两次拉张使得盆地逐步升温,第二次拉张结束时达到历史最高温时期,之后热流持续下降;(3)盆地不同构造部位热流史具有差异性,其中深水区经历的古热流最高,达75mW/m2,礼乐滩最低,仅为63mW/m2。更多还原

【Abstract】 The Lile basin,located in the southern South China Sea,is a complicated superposition basin,for which the research on the tectono-thermal history is little. Based on knowledge of tectonic evolution of the Lile basin,the tectono-thermal history was simulated on seismic profile (L2 section),using a 2D non-uniform model. The thermal evolution of the basin since the Cenozoic era has been attempted by tectono-thermal modeling. The result suggests that(1) The Lile basin has experienced a two-phase extension. The first stretching is lightly with a stretch factor value of 1.05. The second stretching is stronger than the first. The stretch factor value reached 1.3 in deep-water area. (2) The two-phase extension made the basin become hotter and hotter,reaching its climax in paleo-temperature history at the end of the second extension. Then the basin is in the heat flow decreasing period. (3) The heat flow history was diversity in different structure units in the Lile basin. The maximum paleo-heat flow occurred in a deep water area,reaching 75 mW/m2. The minimum was in the Reed bank with a value of 63 mW/m2.更多还原