Modern and fossil ostracode census data from the Western Pacific Ocean and seas around Japan

This data set is part of the Pliocene Research, Interpretation, and Synoptic
Mapping (PRISM) Project.

This data set describes marine ostracode species and related sample and
stratigraphic information produced as part of the USGS PRISM Project (Pliocene
Research, Interpretation, and Synoptic Mapping). The general goals of PRISM
are to reconstruct global climate during a period of extreme warmth about 3
million years ago and to determine the causes of the warmth and the subsequent
climatic change towards colder climates about 2.5 million years ago. To do
this, PRISM has been studying Pliocene deposits and their microfaunas and, by
comparison with modern assemblages, estimating past boundary conditions such as
ocean temperatures. To obtain more reliable estimates of past environments in
paleoclimate studies, the use of ecologically sensitive species requires extensive modern datasets on living species with limited environmental tolerances. Thus, much of the data generated by PRISM consists of species
counts from modern samples that form a "coretop" dataset applicable not only to
PRISM Pliocene assemblages but also to Quaternary assemblages as well.

This situation was especially true for ostracodes, a group of Crustacea that
includes many species that have limited range of water temperatures required
for survival, reproduction, or both. Fossil assemblages of ostracodes can
therefore yield information on past bottom water conditions on continental
shelves in the mixed ocean layer above the thermocline and they are especially
useful where planktic foraminifers are rare or absent. However comprehensive
datasets with quantitative ostracode data were not available for application to
regional paleoceanographic studies. Further, because of the endemic nature of
ostracodes living on continental shelves, separate modern datasets needed to be
developed for regions of the Pacific, Atlantic and Arctic Oceans. The data
contained in the files in this folder come from the western North Pacific
Ocean, mainly the seas around Japan. These regions encompass subtropical to
cold temperate and subfrigid marine climate zones and include faunas from the
major Western North Pacific water masses such as the Oyashio and Kuroshio
current systems.

The ostracode data sets were developed in collaboration with Prof. Noriyuki
Ikeya, Institute of Geosciences, Shizuoka University, Shizuoka, Japan, Prof.
Ikeya's students, and other Japanese colleagues, with support from the USGS
Global Change and Climate History Program and grants from the National Science
Foundation (NSF grant INT: LTV-9013402) and the Japanese Society for the
Promotion of Science (JSPS grant EPAR- 093). Most of the faunal slides are
housed at Shizuoka University.

Separate PRISM ostracode data sets contain modern and Pliocene species data
from continental shelves of the Arctic and Atlantic Oceans and from deep sea
environments.

Among the various types of quantitative analyses used to evaluate the
ostracode data, the Squared Chord Distance (SCD) coefficient of dissimilarity
was found to be useful in identifying modern analog assemblages for fossil
assemblages on the basis of the proportions of shared species between two
samples.

The ostracode data and analyses of them are discussed in detail in the
following published scientific papers:

Ikeya, Noriyuki and Cronin, Thomas. M., 1993, Quantitative analysis of
Ostracoda and water masses around Japan: Application to Pliocene and
Pleistocene paleoceanography: Micropaleontology, v. 39, p. 263-281.

Cronin, T.M., Kitamura, A., Ikeya, N., Watanabe, M., and Kamiya, T.,
in press. Late Pliocene climate change 3.4-2.3 Ma: Paleoceanographic
record from the Yabuta Formation, Sea of Japan: Palaeogeography,
Palaeoclimatology, Palaeoecology.