  We show that if $\mathcal{F}_1$ and $\mathcal{F}_2$ are two transverse
minimal foliations on $M = T^1S$ then either they intersect in an Anosov
foliation or there exists a Reeb-surface in the intersection foliation. The
existence of a Reeb surface is incompatible with partially hyperbolic
foliations so we deduce from this that certain partially hyperbolic
diffeomorphisms in unit tangent bundles are collapsed Anosov flows. We also
conclude that every volume preserving partially hyperbolic diffeomorphism of a
unit tangent bundle is ergodic.
