  We generalize purity of the Newton stratification to purity for a single
break point of the Newton point in the context of local G-shtukas respectively
of elements of the loop group of a reductive group. As an application we prove
that elements of the loop group bounded by a given dominant coweight satisfy a
generalization of Grothendieck's conjecture on deformations of p-divisible
groups with given Newton polygons.
