Gravity field characteristics and orogenic belt structure of the Qinling-Dabie orogenic belt (Hubei section)

On the basis of regional gravity data and through gravity anomaly separation and potential field transformation, the authors revealed the deep structural features of the orogenic belt. In this study, the authors found that the positive linear gravity and magnetic anomaly belt and the details of each order wavelet can clearly reflect the location of the suture belt at the southern edge of the Tongbai-Dabie and East Qinling orogenic belt. The fourth order approximation of the gravity anomaly wavelet can especially obviously reveal the deep structural features. In the"overpass style" two-tier structure displayed in the lithosphere in northwest Hubei, the free space gravity, the isostatic gravity, the residual gravity anomaly and the wavelet details of each order can reflect the nearly EW-extending structural features of the relatively shallow orogenic belts clearly. Each order approximation result reflects the north-south stretching structural features of the relatively deep crust-lithosphere mantle. The analysis and study of the gravity field space form of the orogen belt are of important scientific and practical significance for the study of tectonic deformation of the central orogenic processes, the reconstruction of ancient suture position, the detection of the tectonic framework of the central orogenic belt and the recovery of the flatten process of the North China and South China Plates.