  Multiple initial state parton interactions in p(d)+Au collisions are
calculated in a Glauber-Eikonal formalism. The convolution of perturbative QCD
parton-nucleon cross sections predicts naturally the competing pattern of
low-pT suppression due geometrical shadowing, and a moderate-pT Cronin
enhancement of hadron spectra. The formal equivalence to recent classical
Yang-Mills calculations is demonstrated, but our approach is shown to be more
general in the large x>0.01 domain because it automatically incorporates the
finite kinematic constraints of both quark and gluon processes in the
fragmentation regions, and accounts for the observed spectra in elementary
pp-->\pi+X processes in the RHIC energy range, sqrt{s} = 20-200 GeV. The
Glauber-Eikonal formalism can be used as a baseline to extract the magnitude of
dynamical shadowing effects from the experimental data at differente
centralities and pseudo-rapidities.
