地球物理学进展
地毬物理學進展
지구물이학진전
PROGRESS IN GEOPHYSICS
2009年
6期
1987-1994
,共8页
西沙海槽%反磁化%航磁%残留洋壳%缝合带
西沙海槽%反磁化%航磁%殘留洋殼%縫閤帶
서사해조%반자화%항자%잔류양각%봉합대
Xisha trough%reverse magnetic induction%aeromagnetic data%residual oceanic crust%sutural zone
南海北部西沙海槽存在东西向正磁异常带,长约350 km,前人推测为基性或超基性物质反磁化的反映.通过对西沙海槽大比例尺高精度航磁资料分带化极处理和反演拟合,发现西沙海槽正磁异常带由海槽北缘隐伏强磁性体斜磁化引起.磁性体埋深超过9 km,推测是残留洋壳(蛇绿岩),为海南岛昌江-琼海断裂带或海南岛九所-陵水断裂带所代表的缝合带在南海北部的延伸段.
南海北部西沙海槽存在東西嚮正磁異常帶,長約350 km,前人推測為基性或超基性物質反磁化的反映.通過對西沙海槽大比例呎高精度航磁資料分帶化極處理和反縯擬閤,髮現西沙海槽正磁異常帶由海槽北緣隱伏彊磁性體斜磁化引起.磁性體埋深超過9 km,推測是殘留洋殼(蛇綠巖),為海南島昌江-瓊海斷裂帶或海南島九所-陵水斷裂帶所代錶的縫閤帶在南海北部的延伸段.
남해북부서사해조존재동서향정자이상대,장약350 km,전인추측위기성혹초기성물질반자화적반영.통과대서사해조대비례척고정도항자자료분대화겁처리화반연의합,발현서사해조정자이상대유해조북연은복강자성체사자화인기.자성체매심초과9 km,추측시잔류양각(사록암),위해남도창강-경해단렬대혹해남도구소-릉수단렬대소대표적봉합대재남해북부적연신단.
There is an EW positive magnetic anomaly zone in the Xisha trough of the northern South China Sea which is about 350km long.It is inferred that it results from basic or ultra-basic rock with reverse magnetic induction in the Xisha trough.Based on the large-scale and high-resolution aeromagnetic data reduced to the pole and inversion,it is revealed that the positive magnetic anomaly zone in the Xisha trough is caused by high-magnetic blocks located in the northern margin of the Xisha trough.The high-magnetic blocks are 9 km under ground and possibly residual oceanic crusts(or ophiolites).It is probably a part of the sutural lone that is marked by the Cangjiang-Qionghai fault lone or Jiusuo-Lingshui fault zone in the Hainan Island.
