天津周边海-陆过渡地区航空重力调查及主要成果

Achievements of airborne gravity survey in sea-land transition area around Tianjin

随着人类对海洋矿产资源需求的日益增加,海洋基础地质调查对海洋矿产资源勘探具有重要意义。我国海洋地质地球物理调查起步较晚,整体工作程度较低,而航空重力测量作为一种快速高效的地球物理测量方法,对加强海洋基础地质调查研究具有重要作用。2006年我国引进了国际先进的GT-1A航空重力测量系统,并于2011年首次在天津周边海-陆过渡地区开展了1∶20万比例尺航空重力测量工作,完成了高质量的航空重力测量数据3万测线公里,在海-陆过渡地区实现了海-陆连续测量,填补了研究区内高精度航空重力测量的空白。阐述了本次航空重力调查工作取得的主要成果,并从航空重力的角度对研究区内石臼坨凸起进行了研究,认为石臼坨凸起基底具有分段性,并圈定出新的基岩凸起构造,为石臼坨凸起油气资源的进一步勘探提供方向;同时对渤中凹陷正高磁异常体可能的地质成因进行了探讨。对海-陆过渡地区主要构造单元的重力场特征进行研究,在基底和断裂研究方面取得的新认识对海-陆过渡地区基础地质和环境研究具有重要意义。

Marine geological survey is significant important for the exploration of marine minerals,along with the increasing of human demands for marine mineral resources. The marine geological and geophysics survey in our country started late and is in a lower level now. However,as a quick and effective geophysics measurement,the airborne gravity survey plays an important role in the marine geological survey. The advanced GT- 1 A airborne gravity measurement system was introduced in 2006 and the airborne gravity survey at 1 ∶ 200 000 scale was carried out in sea- land transition region around Tianjin for the first time in 2011. This survey collected 30 thousands kilometers measure data with high quality,implemented the sea- land continuous measurement in the sea- land transition area and filled the blank in the high- precision airborne gravity measure in this area. This paper has given a detailed description of the achievements in airborne gravity survey,and studied the Shijiutuo Salient in the study area from the view of airborne gravity. The basement of Shijiutuo Salient was concluded to be possessed segmentation and the new basement salient was outlined to give a conclusion for further oil and gas exploration. The high magnetic anomaly in Bozhong Depression was also discussed. In addition,some important recognitions were achieved by studying gravity character of the main structural units,basement and fractures in the sea- land transition region,which are important for basic geology and environment research.