The Collaborative International Dictionary of English v.0.48:

paleogeology \paleogeology\ n.
   The study of geologic features once at the surface of the
   earth but now buried beneath rocks.

   Syn: palaeogeology.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

paleogeology
    n 1: the study of geologic features once at the surface of the
         earth but now buried beneath rocks [syn: paleogeology,
         palaeogeology]