overthrust nappe in a sentence

1. To do the investigating and studying work about the achievements of tackling key problem of the quondam exploration of front - zone of mountain , to analyze and study the applicability about the gathering technology used in the seismic exploration of the complicated construction belt of front - zone of mountainous ; 2 . combining the quondam achievements , researching the design method of observation system objective of the complicated construction belt based on seismic - geology model , firstly , building the surface level and deep layer seismic - geology model of complicated construction belt and analyzing the forward model , secondly , designing the observation system aiming at the overthrust nappe structure in section and in area ; 3 . aiming at the complicated earth ' s surface condition of front - zone of mountain , how to select the exciting method and the parameter , how to optimize the environment of exciting method and reception , how to pledge the normal combination of the datum of different exciting method ; 4
2. Owing to complicated earth ' s surface condition such as the steep stratum outcropping of front - zone of mountain or the huge thick gravel stratum ' s overlay and earth ' s surface large undulation , complicated underground geology structure developed extremely such as thrust and overthrust nappe , and violent change of the lateral velocity , etc . in front - zone of mountain there are a series of problems such as serious secondary disturbance and low signal - to - noise ratio in seismic exploration gathering
3. This paper analyzes the sedimentation and the occurrence of the strata in wuxia area and suggests that wuxia area underwent the development of foreland basin of early permian , the overthrust nappe of late permian , the strong structural uplift of late triassic , the weak structural activity of late jurassic and the structural shape of cretaceous followed by finally forming the configuration nowadays
4. It's difficult to find overthrust nappe in a sentence.