应用大地电磁资料识别塔中地区火山岩
|
摘要
由于塔中地区的火山岩层及基底火山岩丘发育,采用地震勘探方法通常难以在火山岩内部及其以下获得比较好的地震资料(主要是火山岩层的屏蔽作用),而利用MT勘探则无此问题,因为电磁波不受高阻地层屏蔽,尤其是火山岩具有高磁化率和高电阻率的特征,从而为在该区应用大地电磁和磁力方法识别火山岩薄层及基底火山岩丘提供了得天独厚的条件。本文利用大地电磁资料高分辨率处理技术,在该区获得了研究区薄层火山岩分布的信息,并结合磁力资料对区内岩浆侵入体基底构造特征进行了刻画、分析,指出了研究区所在的两个局部磁异常区的深层构造均为基底岩浆侵入型构造,为该区钻探部署提供了重要依据。
Since development of volcanic layers and volcanic mounds in basement in Tazhong area, using seismic exploration is usually difficult to acquire better seismic data in the interior of vocatine and below(mainly caused by shield of volcanic layer), but using MT exploration may not produce such problem, because the electromagnetic wave does not suffered from the shield of higher resistance layer; especially the volcanite has the feature of higher magnetic susceptibility and impedance, which provides excellent condition for application of MT and magnetic approaches to identify thin layer of volcanite and volcanic mound in basement. Using high-resolution MT data processing technique,the paper acquires the information of volcanite distribution in studied area,describes and analyzes the structural feature of magmatic intrusive mass basement in the area in combination with magnetic data,which points out that the deep structures of two local magnetic anomalous zones where the studied area is situated are magmatic intrusion structures of basement,which provides an important basis for drilling deployment in that area.
Since development of volcanic layers and volcanic mounds in basement in Tazhong area, using seismic exploration is usually difficult to acquire better seismic data in the interior of vocatine and below(mainly caused by shield of volcanic layer), but using MT exploration may not produce such problem, because the electromagnetic wave does not suffered from the shield of higher resistance layer; especially the volcanite has the feature of higher magnetic susceptibility and impedance, which provides excellent condition for application of MT and magnetic approaches to identify thin layer of volcanite and volcanic mound in basement. Using high-resolution MT data processing technique,the paper acquires the information of volcanite distribution in studied area,describes and analyzes the structural feature of magmatic intrusive mass basement in the area in combination with magnetic data,which points out that the deep structures of two local magnetic anomalous zones where the studied area is situated are magmatic intrusion structures of basement,which provides an important basis for drilling deployment in that area.
引文
[1]周熙襄,钟本善.电法勘探数值模拟技术.四川成都:四川科学技术出版社,1986
[2]王家映.大地电磁拟地震解释法.北京:石油工业出版社,1995
[3]王家映.石油电法勘探.北京:石油工业出版社,1992
[4]Zhdanov MS,Traynin O.Inversion versus migrationin2D geoelectrical problems.Expanded Abstracts of67th SEG Int Meetting,1997,253~256
[5]Constable S C,Parker R L,Constable C G.Occam's in-version:A practical algorithm for generating smooth models from electromagnetic sounding data.Geophys-ics,1987,52(3):289~300
[6]SmithJ T,BookerJ R.Rapidinversionoftwo-and three-di mensional magnetotelluric data.J Geophys Res,1991,96:3905~3922
[2]王家映.大地电磁拟地震解释法.北京:石油工业出版社,1995
[3]王家映.石油电法勘探.北京:石油工业出版社,1992
[4]Zhdanov MS,Traynin O.Inversion versus migrationin2D geoelectrical problems.Expanded Abstracts of67th SEG Int Meetting,1997,253~256
[5]Constable S C,Parker R L,Constable C G.Occam's in-version:A practical algorithm for generating smooth models from electromagnetic sounding data.Geophys-ics,1987,52(3):289~300
[6]SmithJ T,BookerJ R.Rapidinversionoftwo-and three-di mensional magnetotelluric data.J Geophys Res,1991,96:3905~3922
版权所有：© 2023 中国地质图书馆 中国地质调查局地学文献中心