biostratigraphic unit
biostratigraphic unit
[¦bī·ō‚strad·ə′graf·ik ′yü·nət] (geology)
A stratum or body of strata that is defined and identified by one or more distinctive fossil species or genera without regard to lithologic or other physical features or relations.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.