摘要
通过大地电磁探测发现,在海口地区地下深部存在两个低阻体(层),其一位于马鞍岭火山及其以西地区地下深部约5km以上,为浅部低阻层,推测为火山喷出玄武岩覆盖体、地下水及其它低阻物质,该低阻层以下为一正在退化的岩浆通道;其二位于琼山7．5级地震区深部约15km以下,为一直通到上地幔的深部低阻体,推测其为一正在上升的岩浆热源,即岩浆囊。另外还发现,琼州海峡南北两侧的地壳和上地幔结构在电性上具有连续性,推测整个雷琼火山区属于同一地质体,佐证了海南岛属于华南古陆的一部分。
It is discovered there exist two kinds of objects （layers） with low resistance by means of magnetotelluric surveying. One of them locates in the place within 5km far from the earth＇s surface in Ma＇anling volcano and its west. It is a shallow layer with low resistance and consists by inference of basalt cover ejected by volcano, underground water and other substance with low resistance. There is a degenerating magma chunnel. Another of them locates in the place under 15km far from the earth＇s surface in the M7.5 Qiongshan earthquake area. It is a deep layer with low resistance which connects the upper mantle, and is by inference an ascending magma heat-source. In addition, it is found there is electrical continuity from the crust to the upper mantle in the north and south sides of Qiongzhou Straits. It is accordingly inferred that the whole Leiqiong volcanic area is belong to a same geological unit and proved that the Hainan island is one part of the South China ancient continent.
出处
《华南地震》
2007年第1期1-7,共7页
South China Journal of Seismology
基金
地震科学联合基金资助(104123).
关键词
岩浆囊
电性
大地电磁
低阻体
雷琼火山区
Magma bursa
Electricity
Telluric electromagnetism
Low resistance object
Leiqiong volcanic area
