Determination of field-independent and field-dependent components of anisotropy of susceptibility through standard AMS measurement in variable low fields II: An example from the ultramafic body and host granulitic rocks at Bory in the Moldanubian Zone of Western Moravia, Czech Republic
Determination of field-independent and field-dependent components of anisotropy of susceptibility through standard AMS measurement in variable low fields II: An example from the ultramafic body and host granulitic rocks at Bory in the Moldanubian Zone of Western Moravia, Czech Republic
复制标题
通过可变低场中的标准 AMS 测量确定磁化率各向异性的场无关和场相关分量 II：捷克共和国西摩拉维亚摩尔多瑙河区 Bory 的超镁铁体和主粒粒岩示例
DOI：
10.1016/j.tecto.2008.10.014
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发表时间：
2009
期刊：
影响因子：
2.9
通讯作者：
Z. Kratinová
中科院分区：
文献类型：
--
作者：
F. Hrouda;S. W. Faryad;M. Chlupáčová;P. Jeřábek;Z. Kratinová
在捷克西摩拉维亚的Moldanubian带，一个大型超镁铁质岩体（石榴单斜辉石岩和石榴橄榄岩）嵌在长英质麻粒岩中，含有多种磁化率载体。磁化率各向异性（AMS）的低场变化使得独立于场和低场相关的AMS分量的分离成为可能。在麻粒岩中，前者是由顺磁性矿物和磁铁矿的次要混合物携带的，而后者是由于磁黄铁矿。在超镁铁岩中，场无关分量由蛇纹石化形成的纯磁铁矿携带，而场相关分量则由磁黄铁矿和次级顺磁矿物携带。尽管有小的差异，所有AMS组件大致同轴内的麻粒岩和超镁铁岩，但非常不同的麻粒岩和超镁铁岩。这种差异表明，施加在后期麻粒岩组构上的力不足以消除超镁铁岩的原始磁性组构。
A large ultramafic body (garnet clinopyroxenite and garnet peridotite) embedded in felsic granulite at Bory (Moldanubian Zone of Western Moravia, Czech Republic) contains multiple carrier of susceptibility. Low-field variation of anisotropy of magnetic susceptibility (AMS) enables the separation of the field independent and low-field dependent AMS components to be made. In granulite, the former is carried by paramagnetic minerals and a subordinate admixture of magnetite, while the latter is due to pyrrhotite. In the ultramafite, the field-independent component is carried by pure magnetite formed by serpentinization, while the field-dependent component is due to pyrrhotite and subordinate paramagnetic minerals. Despite small differences, all AMS components are roughly coaxial both within granulite and within ultramafite, but very different between granulite and ultramafite. The difference indicates that the forces that imposed the later granulite fabric were not strong enough to obliterate the original magnetic fabric of the ultramafites.