lith·o·stra·tig·ra·phy 
(lĭth′ō-strə-tĭgrə-fē)
(lĭth′ō-strə-tĭgrə-fē)n.
1. Stratigraphy based on the physical and petrographic properties of rocks.
2. Interpretation of the physical characters of sedimentary rocks.
lith′o·strat′i·graphic (-străt′ĭ-grăfĭk) adj.