  We study the intersection of the Torelli locus with the Newton polygon
stratification of the modulo $p$ reduction of certain PEL-type Shimura
varieties. We develop a clutching method to show that the intersection of the
open Torelli locus with some Newton polygon strata is non-empty. This allows us
to give a positive answer, under some compatibility conditions, to a question
of Oort about smooth curves in characteristic $p$ whose Newton polygons are an
amalgamate sum. As an application, we produce infinitely many new examples of
Newton polygons that occur for smooth curves that are cyclic covers of the
projective line. Most of these arise in inductive systems which demonstrate
unlikely intersections of the open Torelli locus with the Newton polygon
stratification in Siegel modular varieties. In addition, for the twenty special
PEL-type Shimura varieties found in Moonen's work, we prove that all Newton
polygon strata intersect the open Torelli locus (if $p>>0$ in the supersingular
cases).
