用解析信号计算化极磁场   总被引：3，自引：0，他引：3  

秦葆瑚 《物探化探计算技术》1997,19(1):78-82

本文论述了二度磁界面上ＡＳ异常与磁化方向无关的证明，并在较复杂的模型上做进一步试算，通过对湘南一个反磁化的应用实例表明：用ＡＳ异常及对ＡＳ异常积分得出化极磁场的方法有较大推广价值  相似文献   

Origin of a magnetic lineation on Kyushu Island, Japan     

Yasukuni  Okubo  Hiroshi  Kanaya  Akitsura  Shibuya Kimio  Okumura 《Island Arc》1997,6(4):386-395

Abstract Several linear magnetic anomalies over continental crust have been identified in and around the Japanese Islands. The anomalies are probably related to island arc tectonic structures, but identifying specific sources has been difficult. Several deep holes were drilled in and around Aso caldera, where a linear anomaly occurs along an active fault. One drillhole located on the linear anomaly encountered a zone of highly magnetized and altered basement rocks at least 100 m thick at a depth of ∼1000 m. The other hole was located away from the anomaly and did not encounter any high-magnetic zones. Rocks from the zone have exceptionally strong remanent magnetization (several tens of A/m) sub-parallel to the present field. AF demagnetization experiments indicated that the magnetization is hard and stable. Magnetic modeling indicates that the linear anomaly is caused mainly by this layer. Microscopic examination of core samples shows that the highly magnetized zone includes secondary magnetic minerals and abundant hydrothermal alterations. Temperatures determined by fluid inclusions and down-hole temperatures show that the temperature of the highly magnetized zone was elevated in the past relative to surrounding rocks. The high temperature could destroy primary magnetic minerals and replace them with secondary magnetic minerals. Thus, the past hydrothermal system may have enhanced thermo-chemical remanent magnetization. The results can produce a model indicating that there was a past hydrothermal system related to the tectonic structure.  相似文献   

Palaeomagnetism of Permian red beds from south Kazakhstan: DRM inclination error or CRM shallowed directions?     

Mikhail L. Bazhenov  Valerian L. Klishevich  Vladimir A. Tselmovich 《Geophysical Journal International》1995,120(2):445-452

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The roles of steady and alternating fields playing in the anhysteretic process   总被引：1，自引：0，他引：1  

Zongyang Liu 《Geophysical Journal International》1995,121(2):354-358

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Analysis of Multi-Component Natural Remanent Magnetization Based on the Thermal Demagnetisation Spectrum     

Man  Otakar 《Studia Geophysica et Geodaetica》2003,47(2):359-370

Natural remanent magnetization as a differentiable vector function of temperature is estimated from thermal demagnetization data. Its first derivative is crucial to the interpretation, since the local maxima of its absolute value reveal the temperature intervals where the magnetization is changing most rapidly, but the direction of a partial thermoremanent magnetization may be relatively stable.  相似文献   

等温剩磁获得曲线的累积对数高斯模型在泥河湾盆地磁组分识别中的运用   总被引：3，自引：0，他引：3  

王喜生  李学军 《地学前缘》2003,10(1):163-169

基于饱和等温剩磁(SIRM)获得曲线遵循累积对数高斯模型(CLG)的假设，利用改进的CLG模型分析，成功地对采自泥河湾河—湖相层上部的许家窑剖面样品所含的主要载磁组分进行了分离；结合先前的岩石磁学结果，进一步验证了高矫顽力的赤铁矿和低矫顽力的磁铁矿／磁赤铁矿为许家窑样品的主要载磁矿物，并对各磁组分对SIRM的贡献进行了定量估算；对CLG模型的优缺点和实用性进行了探讨；结合剩磁矫顽力曲线特征，尝试提出了X参数的概念。  相似文献   

Rock magnetic properties of Nihewan sediments at Xujiayao     

王喜生  Lφvlie Reidar  苏朴 《中国科学D辑(英文版)》2002,45(10):939-948

Rock magnetic measurements of Nihewan sediments from Xujiayao section demonstrate that magnetite, hematite and maghemite are dominant remanent magnetization carriers. Monitoring the variations of magnetic susceptibility (MS) and saturating isothermal remanent magnetization (SIRM) at low temperature are the attractive ways of detecting the presence of magnetite, maghemitization and superparamagnetic grain sizes. Low-temperature MS investigations suggest that susceptibility enhancement for Xujiayao samples is mainly due to the remarkable presence of SD/MD magnetite to some degree though some magnetite grains have been partially oxidized at some depths. It is tentatively concluded that both SD/MD magnetite and hematite are of detrital origin and carry a characteristic remanent magnetization (ChRM), whereas maghemite can be attributed to be chemical origin, overprinting a reversed polarity component of Matuyama age.  相似文献   

Axial magnetic anomalies over slow-spreading ridge segments: insights from numerical 3-D thermal and physical modelling     

Sébastien Gac  Jérôme Dyment  Chantal Tisseau  Jean Goslin 《Geophysical Journal International》2003,154(3):618-632

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A lock-in model for the complex Matuyama-Brunhes boundary record of the loess/palaeosol sequence at Lingtai (Central Chinese Loess Plateau)   总被引：1，自引：0，他引：1  

S. Spassov  F. Heller  M. E. Evans  L. P. Yue  T. von Dobeneck 《Geophysical Journal International》2003,155(2):350-366

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Drilling-induced remanent magnetization in basalt drill cores     

Haraldur Audunsson  Shaul Levi 《Geophysical Journal International》1989,98(3):613-622

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