东海陆架盆地及其周边海域地质、地球物理场特征

THE CHARACTERS OF GEOLOGY AND GEOPHYSICS OF SHELL BASINS OF EAST CHINA SEA AND ADJACENT SEA AREA

分析了东海陆架盆地及其周边海域的重、磁场特征 ,对研究区域的地球物理场资料进行了小波变换与多尺度分析与计算 ,计算了研究海域重、磁资料的 1～ 4阶小波变换逼近、细节 .根据分析与计算可知 ,在东海陆架盆地及其周边区域 ,重、磁异常的主要特征没有内陆盆地那样明显 ,但盆地内的绝大部分地区均位于异常相对缓变区 ,在盆地内部有时有局部异常的圈闭及剧变区 ,但总的特征为缓变的 .而周边区域多为相对剧变区 ,但也存在局部区域的缓变带 .重、磁场特征表明 ,盆地基底相对盆地周边区域主要由密度较大、磁性较强的岩石组成 ,因此盆地中部以高正磁异常为主 ,布格重力异常也相对周边地区高 .东海陆架盆地及其周边海域的重力场的主要走向为NNE向 ,局部重力异常变化较为平缓 .磁异常走向没有重力异常明显 ,但主要也为NNE向 .重、磁场的分布特征表明 ,东海陆架盆地及其邻域的地质构造为大陆架构造的延伸 .

This paper analyzed the characters of gravity and magnetic fields of shell basins of East China sea and adjacent area. Wavelet transform and multiresolution analysis of gravity and magnetic data of the study area were calculated. According to results of calculation, the characters of gravity and magnetic fields of the study area are not distinctness compared with main land basins. But the main part of basin is also situated in relatively relaxed changed area of anomalies. In interior of basin there are a few local upheaval area of anomalies. But the main characters are relaxed. In border area of basin is mostly relatively upheaval area of anomalies. But there are local relaxed areas in border area. The characters of gravity and magnetic fields show that floor of basin relative border area are high density and magnetism rocks. In middle part of basin, magnetic anomaly is positive and high. Buger gravitational anomaly is high compared with border area. Main tend towards of gravity field is NNE. Local gravitational anomaly changed smoothly. Tend towards of magnetic anomaly is not distinctness compared with gravity anomaly. But it is also NNE. The characters of gravity and magnetic fields show that geological construct of East China sea and adjacent area is extension of continent structure frame.