  In this paper we study general torus actions on manifolds with isolated fixed
points from combinatorial point of view. The main object of study is the poset
of face submanifolds of such actions. We introduce the notion of a locally
geometric poset -- the graded poset locally modelled by geometric lattices, and
prove that for any torus action, the poset of its faces is locally geometric.
Next we discuss the relations between posets of faces and GKM-theory. In
particular, we define the face poset of an abstract GKM-graph and show how to
reconstruct the face poset of a manifold from its GKM-graph.
