Collaborative Research: Fabric and Seismic Anisotropy within the Lithospheric Mantle: Magnetic and Petrofabric Studies of Shear Zones in the New Caledonia Ophiolite

目前正在研究新喀里多尼亚蛇绿岩自然剪切带地幔橄榄岩组构和各向异性的发展情况，方法是结合使用电子反向散射衍射和高场磁化率各向异性技术，以确定晶格优先取向。电子背散射衍射提供了一个精确的测量晶格择优取向，并产生滑移系和变形温度的信息。高场磁化率各向异性是一种新的方法，它通过分离硅酸盐的磁性贡献来提供组构主轴的取向和各向异性的程度。高场各向异性的磁化率方法是相当快，比电子背散射衍射，因此，允许映射的变形梯度在一个更高的分辨率。该项目正在定量确定高场磁各向异性与矿物组构各向异性之间的相关程度，这是利用电子反向散射衍射和其他公认的方法，如通用台技术确定的。如果成功，新方法将允许更快地研究大面积的地幔组构，从而有助于解释地幔的地震各向异性数据。

The development of fabric and anisotropy in mantle peridotites in natural shear zones of the New Caledonia ophiolite is being studied using a combination of electron backscatter diffraction and high-field anisotropy of magnetic susceptibility techniques to determine lattice preferred orientation. Electron backscatter diffraction provides an accurate measurement of lattice preferred orientation and yields information on slip systems and deformation temperatures. High-field anisotropy of magnetic susceptibility is a new method that provides the orientation of the fabric main axes and the degree of anisotropy by isolating the magnetic contribution of silicates. The high-field anisotropy of magnetic susceptibility method is considerably faster than electron backscatter diffraction and, therefore, allows mapping of deformation gradients at a higher resolution. The project is quantitatively establishing the degree of correlation between high-field magnetic anisotropy and mineral fabric anisotropy determined using electron backscatter diffraction and other well-established methods such as the universal stage technique. If successful, the new method will permit more rapid study of mantle fabrics over a large area, thus aiding interpretation of seismic anisotropy data from the mantle.