法国中央高原的新构造活动研究

STUDY ON THE NEOTECTONIC ACTIVITY OF THE FRENCH CENTRAL PLATEAU

本文论述了法国中央高原及毗邻地区的新生代地层、地貌、构造形迹和火山活动等所反映的新构造活动类型及特征,综合分析了中央高原的隆升和构造应力场的演变。提出了高原强烈抬升时期为中更新世以来的观点,以及新生代各时期高原主要经受南北向挤压作用,其间辅以东西和北西—南东方向挤压作用的新认识。

The French Central Plateau Massif, dipping very gently to the northwest, is located in the west of the Rhone River and between two NNE-tren-ding deep faults. The elevation of its top is 1200m above sea-level. There are many Cenozoic pyroclastic volcanic layers and various NW-SE or N-S grabens in the massif. Also exist are a large number of NW tensile structures and a few NE compressive structures; or a few NW compressive structures and NE tensile structures in the Oligocene of the massif. They were formed respectively in the Pyrenessian type of S-N compressive stress field and the Alpesin E-W compressive stress field. The former played the dominant role during the Cenozoic. The activity of the massif was very strong at the southeast edge, with faults of great vertical displacement and different mechanical behavior and polyperiodic activity. The plateau has experienced intermittent upwarping as a result of successive intensive marginal faulting with the maximam upwarping occurring during and ofter the Middle Pleistocene.