Correlating magnetic fabrics with finite strain: Comparing results from mudrocks in the Variscan and Appalachian Orogens

摘要: New magnetic anisotropy data from Variscan mudstones collected in the Cantabrian Arc, N Spain constrain corresponding strain (shortening). The results are based on our previous study of mudrocks Valley and Ridge Province (Appalachians) where independent quantification pencil structures permitted a correlation between fabric tectonic strain. An exponential relationship AMS shape parameter T shortening was found for interval 10-25% shortening: (%)=17*exp(T), that appears to be supported by strains up 40%. describes susceptibility ellipsoid, which pelitic rocks more sensitive than degree P (or P’). In Arc positive deformation intensity, reflected cleavage domains spacing, is observed. Using above relationship, we estimate range mudstones. offers robust magnitude 10-40% weakly moderately deformed clay-rich rocks, other indicators often lacking or poorly preserved.