Characteristics of magnetic fabrics of the Karakoram fault belt and its tectonic significance.

This paper deals with the characteristics of magnetic fabrics of the Karako ram fault belt. The geometric mean values of the susceptibilities vary with minerals and their contents. Most of the susceptibility ellipsoids are str ongly oblate with very accurately defined foliation planes and minimum axis orientations. The corrected anisotropy degree P-1 differs between the less and more deformed racks. The minimum axis directions, which are assumed to reflect the directions of maximum principal stress direction, mostly trend NE-SW. Considering the NNW-SSE striking Karakoram fault, determination of the direction of movement is demonstrated. The overall movement is horizont ally dextral and the west wail in localised units moves vertically upward o r downward with respect to the east one. Isotopic dating shows that this mo vement occurred between 6. 88+/-0. 36 and 8. 75+/-0. 25Ma. This set of new quantitative analyses of anisotropy of magnetic susceptibility, together wi th the structural analysis, is in agreement with the geodynamic evolution o f the Karakoram fault belt.