We examined 75 samples from Unit I, Hole 1149A for diatoms. Fifty samples ranging from early Pliocene to late Pleistocene in age contained 139 diatom species and were attributable to the Neodenticula kamtschatica through Neodenticula seminae zones of the North Pacific diatom zonation and to the Nitzschia jouseae through Pseudoeunotia doliolus zones of the equatorial Pacific diatom zonation. Patterns of diatom abundance in Unit I correlate well with the diatom events of Barron. The data seem to show Barron's Events C and D and increases in diatom sedimentation in the late Pleistocene not specifically named by Barron but shown in his data. Inconsistencies of species ranges compared to published data suggest either extensive reworking or biogeographic control of first and last occurrences for some zonal indicator species. The presence of displaced Miocene, neritic, and benthic taxa strongly suggests aqueous or eolian transport of materials from coastal environments and/or land-based outcrops.

Sediment depth is given in mbsf. Abundance estimate as follows: A = abundant (15% or greater), C = common (4-14.9%), F= frequent (1-3.9%), and R = rare (<1%), - = not found. A known quantity of Lycopodium sp. pollen grains and Rose Bengal dye were added to each sample to permit later estimations of diatom abundance (diatom number/g). All diatom species were identified and counted at 1250x using the ribbon counting method, until at least 500 specimens were counted or 15 traverses (ribbons) were completed, whichever came first.

Supplement to: Olschesky, Karyn S; Laws, Richard A (2002): Data report: Pliocene-late Pleistocene diatom biostratigraphic data from ODP Leg 185, Hole 1149A. In: Ludden, JN; Plank, T; Escutia, C (eds.) Proceedings of the Ocean Drilling Program, Scientific Results, College Station, TX (Ocean Drilling Program), 185, 1-31