In this paper we deal with
codimension-1 measured laminations whose leaves are minimal surfaces in geometric
3-manifolds with either SL2R or H2× E structures. We call such measured
laminations minimal measured laminations. Our main theorem states that in a
geometric 3-manifold with an SL2R-structure every class in R𝒮 containing
incompressible measured laminations is represented uniquely by a minimal measured
lamination. This implies that every incompressible lamination in such a 3-manifold is
equivalent to a unique minimal measured lamination, which is vertical with respect to
geometric fibering structure.