Cevennes盆地北坳陷区独特的沉积与构造演化的耦合关系

Sedimentary and tectonic evolution of the North Depression in the Cevennes coal basin,France

发育于法国Cevennes聚煤盆地北坳陷区斯蒂芬期 (Stephanian)同沉积断层在空间上局部控制了碎屑体及煤层的形态、厚度 ,且在时间上完成了构造反转。盆缘断层控制了盆地自身的几何形态及其岩相古地理格局 ,它们的活动性及强度的差异致使盆地沉降或沉积中心、富煤带的侧向迁移 ,使盆地整体的构造格架发生了由半地堑 地堑 新型式的半地堑的转化。在不同的演化时期 ,盆地独特的沉积、充填作用对构造的活动与演化给予了积极的响应 ,体现了两者间清楚的耦合关系。盆地的充填与构造的活动方式及强度又与盆地周围古构造应力场在斯蒂芬期所发生的变化息息相关。

Exemplified by the North Depression of the Stephanian Cevennes coal basin on the Massif Central in France,this paper discusses the sedimentary dynamics and synsedimentary structures in relations to basin tectonism.Spatially,the synsedimentary faults control the morphology and thickness of clastic rock bodies and coal seams,and the peribasinal faults control the geometry and sedimentary facies and palaeogeographic framework of the basin.The differences in fault actvity and intensity lead to the basin subsidence or the laternal migration of the depocentres and coal rich zones, and to the tectonic evolution of the basin from a half graben through a graben to a new type of half graben. The deposition and filling of the basin during different stages are interpreted to be in response to tectonic activity,and the modes and intensity of basin filling and tectonism are in turn closely bound up with the variations in the Stephanian peribasinal palaeostructural stress fields.