Standard planktonic foraminiferal zones developed for tropical faunas can be estimated in mid- to high-latitude faunal assemblages of the northeast Pacific on the basis of recognition of major paleoclimatic-paleoceanographic events, quantitative distribution of Neogloboquadrina pachyderma morphotypes, and coiling ratio of this species in addition to the presence of key taxa. The late Neogene foraminiferal assemblages of DSDP site 173, off northern California, have been quantitatively analyzed and zoned by correlation with the central North Pacific DSDP site 310; multiple correlations of other microfossil groups support this correlation. Site 173 can thus serve as a reference section for zonation of sediments...