The Collaborative International Dictionary of English v.0.48:

Unstratified \Un*strat"i*fied\, a. (Geol.)
   Not stratified; -- applied to massive rocks, as granite,
   porphyry, etc., and also to deposits of loose material, as
   the glacial till, which occur in masses without layers or
   strata.
   [1913 Webster]

WordNet (r) 3.0 (2006):

unstratified
    adj 1: not deposited in layers; "glacial till is unstratified"
           [ant: bedded, stratified]