View source for BGS Zone 18 (=uppermost UKB14 and lower UKB15 of Hart et al., 1989)

'''Base: '''Inception of ''Gavelinella cristata''.

'''Top: '''Inception of ''Bolivinoides culverensis. ''

'''Biomarkers:'''

* ''Stensioeina granulata polonica'' extinction at Peake’s Sponge Bed.

* ''Stensioeina exsculpta gracilis'' inception in the middle part of the foraminiferal zone, at the ''Echinocorys'' ''elevata'' Band and lateral equivalents at the base of the ''M. testudinarius'' macrofaunal zone.

'''Subzones:'''

'''18i'''. (un-named subzone). Inception of ''Gavelinella cristata'' and ''Gavelinella stelligera'' to the inception of ''Stensioeina granulata perfecta''

'''18ii'''. ''<u>Stensioeina granulata perfecta</u>''<u> Subzone</u>: marked by the inception of the index species in the ‘mid’ ''U.'' ''socialis'' macrofaunal zone.

'''18iii'''. ''<u>Bolivinoides strigillatus</u>''<u> Subzone:</u> marked by the inception of the subzonal index in the upper ''U. socialis'' macrofaunal zone, a little below Hawks Brow Flint and lateral equivalents.

'''18iv'''. (un-named subzone). Inception of ''Rosita fornicata, Rugoglobigerina pilula, Archaeoglobigerina cretacea'' and ''Heterohelix striata'' at the base of the ''U. anglicus'' macrofaunal zone.

'''Macrofaunal correlation''': topmost ''M. coranguinum'' Zone (immediately below Peake’s Sponge Bed and lateral equivalents), ''U. socialis'' Zone, ''M. testudinarius'' Zone & ''U. anglicus'' Zone.

'''Age: '''Late Santonian & Early Campanian

[[Category:Foraminiferal zonation | 018]]