  We establish the well-posedness of an initial-boundary value problem of mixed
type for a stochastic nonlinear parabolic-hyperbolic equation on a space domain
$\cO=\cO'\X\cO''$ where a Neumann boundary condition is imposed on
$\po\cO'\X\cO"$, the hyperbolic boundary, and a Dirichlet condition is imposed
on $\cO'\X\po\cO"$, the parabolic boundary. Among other points to be
highlighted in our analysis of this problem we mention the new strong trace
theorem for the special class of stochastic nonlinear parabolic-hyperbolic
equations studied here, which is decisive for the uniqueness of the kinetic
solution, and the new averaging lemma for the referred class of equations which
is a vital part of the proof of the strong trace property. We also provide a
detailed analysis of the approximate nondegenerate problems, which is also made
here for the first time, as far as the authors know, whose solutions we prove
to converge to the solution of our initial-boundary value problem.
