  We calculate the (super)decomposition matrix for a RoCK block of a double
cover of the symmetric group with abelian defect, verifying a conjecture of the
first author. To do this, we exploit a theorem of the second author and Livesey
that a RoCK block $\mathcal B^{\rho,d}$ is Morita superequivalent to a wreath
superproduct of a certain quiver (super)algebra with the symmetric group
$\mathfrak S_d$. We develop the representation theory of this wreath
superproduct to compute its Cartan invariants. We then directly construct
projective characters for $\mathcal B^{\rho,d}$ to calculate its decomposition
matrix up to a triangular adjustment, and show that this adjustment is trivial
by comparing Cartan invariants.
