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为了绘制Brittany南部(法国西部)的Guerande 浅色花岗岩同构造期岩浆构造图,采用了以下的综合方法:一方面,进行广泛的野外调查工作和室内镜下观察;另一方面,开展详细的磁性组构调查。通过前一项研究,得出岩浆流面的走向一般为ENE—WSW,向北缓倾;而岩浆流动方向为NNE,倾角中等。并由此推断该岩体为一个根基不深的叶片状体。由磁化率各向异性所确定的磁性组构主要与赤铁矿—钛铁矿晶粒有关,而它们的平均岩石磁化率约为3.10~(-6)克/奥斯特。磁性条带(Kmax)与岩浆流动方向非常吻合,而磁性层(Kmax—Kint面)与岩浆流面的吻合性较差。磁化率各向异性的定量分析使我们有可能把数据分成两个区域:一个呈面线状椭球体,与主要呈粘性流动的花岗岩体的中心部分相当;另一个压扁域与北部边缘区有关,在那里出现初始阶段的正片麻岩化,即固态条件下的某种变形。与传统构造方法的这种有效对比。将鼓舞我们在岩石的显微构造状况已经十分清楚的情况下,可以把磁化率各向异性方法作为花岗岩岩体构造填图的较为常规的方法加以使用。
In order to map the magmatic tectonic maps of the Guerande light-colored granites in the southern Brittany (western France), the following synthetic methods were used: on the one hand extensive field investigation and microscopic observations in the interior; on the other hand detailed magnetic Organization survey. According to the previous study, it is concluded that the trend of magmatic flow surface is generally ENE-WSW, easterly toward the north; and magmatic flow direction is NNE with moderate dip angle. It is deduced that the rock mass is a leaf-shaped body that is not deeply rooted. The magnetic structure determined by susceptibility anisotropy is mainly related to the hematite-ilmenite grains, and their average rock magnetic susceptibility is about 3.10-6 grams / oersted. The magnetic band (Kmax) is in good agreement with the magma flow direction, while the magnetic layer (Kmax-Kint surface) is less consistent with the magma flow surface. Quantitative analysis of magnetic susceptibility anisotropy has made it possible to divide the data into two areas: a surface-line-shaped ellipsoid that is comparable to the central part of a mainly viscous-flowing granite body and the other crushed area that is related to the northern margin area , Where there is a positive gneiss at the initial stage, a deformation under solid conditions. This is an effective comparison with the traditional method of construction. Will encourage us to use the magnetic susceptibility anisotropy method as a more conventional method of mapping granitic rock mass structures, given that the microstructural conditions of the rock are well established.