  Block copolymer (BCP) melt assembly has been the subject of decades of study,
with focus largely on self-organized spatial patterns of periodically-ordered
segment density. In this study, we demonstrate that underlying these otherwise
well-known composition profiles (i.e. ordered lamella, cylinders, spheres and
networks) are generic and heterogeneous patterns of segment orientation that
couple strongly to morphology, even in the absence of specific factors that
promote intra- or inter-chain segment alignment. We employ a combination of
self-consistent field theory and coarse-grained simulation methods to measure
polar and nematic order parameters of segments in a freely-jointed chain model
of diblock melts. We show that BCP morphologies are generically characterized
by a {\it multizone} texture, with segments predominantly aligned normal and
parallel to inter-domain interfaces in the respective brush and interfacial
regions of the microdomain. Further, morphologies with anisotropically-curved
interfaces (i.e. cylinders and networks) exhibit biaxial order that is aligned
to the principal curvature axes of the interface. Understanding these generic
features of intra-domain texture provide new opportunities for manipulating
multi-scale structure and functional properties of BCP assembly.
