摘要
位于我国南海南部南沙海槽东南缘深水逆冲推覆构造系统记录着古南海俯冲与消亡及南海扩张的演化史,为现今仍在活动的构造系统。本文综合阐述了深水逆冲推覆构造的几何学和运动学特征、形成时代和形成过程,并结合区域地质背景探讨其动力学机制,建立构造演化模式。研究结果表明,基于几何学特征差异该构造系统在平面上可划分为南段和北段,垂向上分为上部逆冲推覆构造体系和下部逆冲推覆构造体系。受控于动力学机制,北段褶皱构造变形强度明显大于南段,体现在相邻逆冲褶皱排列间距明显小于南段。综合区域地质背景分析认为:下部逆冲推覆构造体系变形机制为晚白垩世—早中新世古南海俯冲消亡于婆罗洲之下的地壳缩短作用,而上部逆冲推覆构造体系变形机制为中中新世以来三角洲推进的重力滑脱作用与苏禄海盆扩张的地壳缩短作用的叠加结果。
Located in southeastern Nansha Trough,Deep-water Fold and Thrust Tectonics （DFTT） which is still active at the present-day,recorded tectonic history of subduction of proto-South China Sea and seafloor spreading of the South China Sea.Geometry,kinematics,age and development of DFTT are discussed in this paper.Combined with regional geological settings,dynamic mechanism is discussed,and the tectonic evolution model is established.The results show that DFTT is divided into southern part and northern part in lateral,and into upper fold and thrust system and lower fold and thrust system in vertical.Controlled by different dynamic mechanisms,anticline intervals and deformation degree are much more intense in the southern part than that of the northern part.The lower fold and thrust system was formed because of subduction of proto-South China Sea beneath the Borneo continental block during Late Cretaceous to Early Miocene.And the formation of upper fold and thrust system is associated with delta gravitational gliding and crustal shortening of seafloor spreading of Sulu Sea during Middle Miocene to present-day.
出处
《地质论评》
CAS
CSCD
北大核心
2015年第5期1061-1067,共7页
Geological Review
基金
国土资源部海底矿产资源重点实验室开放基金项目(编号KLMMR-2013-A-12)
国家自然科学基金项目(编号41276054)
国家地质调查专项(编号GZH201300503)
国家基础地质数据更新与集成工程专项(编码12120115071001)的成果
关键词
逆冲推覆构造
构造演化
南沙海槽
南海
fold and thrust tectonics
tectonic evolution
Nansha Trough
the South China Sea
