江西永丰-崇仁盆地晚白垩世构造-沉积演化

The late Cretaceous tectonic-sedimentary evolution of Yongfeng-Chongren basin in Jiangxi Province

本文分析了江西永丰-崇仁盆地上白垩统河口组、塘边组和莲荷组的沉积特征及沉积环境,认为其主要为一套洪冲积扇-辫状河-滨浅湖相沉积;研究了永丰-崇仁盆地晚白垩世沉积与构造的耦合过程,识别出3个构造-沉积演化期,即河口期、塘边期及莲荷期。河口期在剧烈断陷拉张作用下发育河流-冲积扇相沉积;塘边期构造相对稳定,断陷拉张作用减弱,发育河流-湖泊相沉积;莲荷期构造以盆地西北侧地层相对隆升为主,发育河流-冲积扇相沉积。本文认为永丰-崇仁红盆的形成和演化明显受到构造运动、气候及物源的控制。

This paper analyzes the sedimentary characteristics and depositional environments of the upper Cretaceous Hekou Formation, Tangbian Formation and Lianhe Formation of Yongfeng-Chongren basin in Jiangxi Province. It is regarded that the sedimentary facies are mainly consisted of fluvial-alluvial fan-braided river-coastal shallow-lake facies. By studying the Late Cretaceous sedimentary and tectonic coupling process of Yongfeng-Chongren basin, three tectonic-sedimentary evolution periods, including Hekou peri- od, Tangbian period and Lianhe period are recognized. Affected by fault-extension tectonics, fluvial-alluvi- al fan depositional system was developed in the Hekou period; in the Tangbian period, the tectonic movement was relatively stable and the fault-extension tectonics was decreased, fluvial-lacustrine depositional system was developed; it was developed fluvial-alluvial depositional system in the Lianhe period when the strata in the west-north basin was relatively rising. It is considered that the formation and evolution of Yongfeng-Chongren red basin was significantly controlled by tectonic movement, climate and provenance.