  We study prime ideals in skew power series rings $T:=R[[y;\tau,\delta]]$, for
suitably conditioned right noetherian complete semilocal rings $R$,
automorphisms $\tau$ of $R$, and $\tau$-derivations $\delta$ of $R$. These
rings were introduced by Venjakob, motivated by issues in noncommutative
Iwasawa theory. Our main results concern "Cutting Down" and "Lying Over." In
particular, under the additional assumption that $\delta = \tau - id$ (a basic
feature of the Iwasawa-theoretic context), we prove: If $I$ is an ideal of $R$,
then there exists a prime ideal $P$ of $S$ contracting to $I$ if and only if
$I$ is a $\delta$-stable $\tau$-prime ideal of $R$. Our approach essentially
depends on two key ingredients: First, the algebras considered are zariskian
(in the sense of Li and Van Oystaeyen), and so the ideals are all topologically
closed. Second, topological arguments can be used to apply previous results of
Goodearl and the author on skew polynomial rings.
