Remanent magnetization and magnetic susceptibility anisotropy measurements in Lac des Mille Lacs area of northwestern Ontario: Discussion

摘要: In their recent paper on the magnetic susceptibility anisotropy of some metavolcanic rocks in northwestern Ontario, Nwachukwu and Currie concluded that prolateness factor (P) ellipsoid increases with increasing amount paleostrain, P "can be used qualitatively to determine areal variations magnitude deformation ..." (1975, p. 743, 1.7). A similar conclusion, based reciprocal values P, had been reached by Khan (1962) thirteen years ago. He suggested "deformations intense enough produce large (susceptibility) anisotropies tend (magnetically) linear rather than planar structures" (1962, 2879, 1.50). But this generalization is at variance results conventional strain analysis. reliable parameter for any (Nye 1957, 47) should independent anisotropy. I will attempt show above greatly affected amounts anisotropy, not as a measure if these are unknown. Furthermore, label has attached different parameters literature which was recognized (1975). Only suite deformed constant proleteness ellipsoid, may magnitude. The shape triaxial principal semi-axes K, > K2 K3 can described combination two : (1) (departure from sphericity), (2) ratio. generally specified K,/K3 or 100(K, K3)/K,, but variety expressions (2). For instance,