Selecting two geologic models:dome model with homogeneous overlying medium and dome and fault model with overlying fractured formation,over which a ordinary 3 D seismic data acquisition,processing and analysis have been done and following results are obtained:① seismic physical model experiment can fully model 3 D geologic structural body;② wavefield feature of eac.

This paper introduces various data about Longshan dome (brachy-anticline) in Xinshaocounty, Hunan Province, China, and demonstrates that the dome (brachy-anticline) doesnot exist there on the basis of the definitions of dome and brachy-anticline, geologic sectionsand occurrence of the strata of Longshan area, as well as proposes a new viewpoint on thestructure of the district.