U.S. Geological Survey

Global Change Research Program

Arctic ostracode database: An introduction

T.M. Cronin,
T.R. Holtz, Jr.,
E.M. Brouwers,
W.M. Briggs, Jr.,
R.C. Whatley, and
A. Wood

Introduction

The Arctic Ostracode Database provides species census data for about 100 species of benthic marine Ostracoda from modern surface and late Quaternary sediments from various parts of the Arctic Ocean and adjacent seas. This readme file describes the sources of the ostracode data provided in the accompanying data files. Ostracodes are a microfossil group of bivalved Crustacea that secrete a calcareous shell commonly preserved in sediments in the Arctic region. Because many ostracode species have ecological limits controlled by temperature, salinity, oxygen, food and other factors, they can provide an important tool for paleoceanographic reconstruction in the Arctic. Some recent applications of ostracodes to understanding Arctic Ocean history include Briggs (1983), Reimnitz et al. (1983, 1992), McDougall et al. (1986), Clark et al. (1990), Pak et al. (1992), Brouwers et al. (1991), Cronin et al. (1993, 1994, 1995), Penney (1993a,b), Nurnberg et al. (1994), and Briggs and Mudie (in prep.).

The information given here is supplemented by an annotated list of digital files and formal metadata in FAQ-style HTML and indented text formats.

Ostracode Data Files

All files are tab-delimited ASCII text, meaning that columns are separated by the tab character (ASCII 9). It should be straightforward to import these data into a spreadsheet or database application, provided the tab characters are preserved during the transfer across the network. To ensure that the tabs are preserved, load the files directly to your local disk, don't save them from a web browser's display window.

taxa.txt Taxonomic name table

This file lists the names of 103 taxon categories used in the other three files containing the species census counts. Most of the 103 categories represent individual ostracode species; a few (i.e., Polycope) are genus- level categories, used because the taxonomy of a particular genus is not well understood. Category 100 represents "other", unidentified species. Category 101 includes ice-rafted ostracodes (IRO) representing shallow water species believed to be transported into deeper water sediments by Arctic Ocean sea-ice. Category 103 in ostarcfos file represents taxa from the Atlantic Ocean. Twenty-one species have the designation "SCD", which stands for Squared Chord Distance. These are those species used in the Modern Analog Technique quantitative analyses described in Cronin et al. (1995).

The contributors to the Arctic Ostracode Database generally agree on the taxonomic identification of most Arctic ostracodes, although additional work is required in some groups such as Cytheropteron. Readers are referred to the following sources and the references therein for formal taxonomic treatment of Arctic taxa: Sars (1866, 1922-28), Elofson (1941), Neale and Howe (1975), Joy and Clark (1977), Cronin (1981; 1988), Whatley (1982), Penney (1989), Hartmann (1992), Whatley and Coles (1987), and Whatley and Eynon (1995).

location.txt Sample location data

Sample identifiers, geographic location, and water depth are given in this file. The identifiers given here are those used in the other data files. A question mark is shown where locality information is not known.

modern.txt Modern census data

This file contains species census data from 403 modern ostracode assemblages obtained from coretops, grab and surface sediment samples. Taxon numbers 1-101 in the column headings are keyed to the taxonomic name table (taxon numbers 102 and 103 are not recognized in coretop samples and are only used in the fossil census data in file fossil.txt and the multicore (MUC) census data in file multicor.txt). The published sources of species occurrence data and the repositories of the faunal slides are as follows. Cronin et al. (1991) compiled a Modern Arctic Ostracode Database (MAOD) that included mostly shallow water samples from four repository laboratories: Aberystwyth (Institute of Earth Studies, University College Wales, R.C. Whatley and A. Wood), Boulder, Colorado (INSTAAR, University of Colorado, W.M. Briggs, Jr.), Denver, Colorado (U.S. Geological Survey, E.M. Brouwers), Reston, Virginia (U.S. Geological Survey, T.M. Cronin). MAOD gave the longitude, latitude, water depth of the samples and the repository for each. Most of the shallow water samples from MAOD containing more than 20 individual specimens of ostracodes are included in this modern sample database (several sites from latitudes below 50°N were excluded); taxonomy for a few species was updated and a few typographical errors were corrected. Cronin et al. (1994) provided species census data from 43 coretop samples obtained during the 1991 cruise of the Polarstern to the Arctic Ocean. Station data for these are given in Fütterer (1992). Cronin et al (1995) provided additional coretop ostracode census data from other deep water regions of the Arctic and the adjacent Nordic Seas obtained during several Polarstern and Meteor cruises and the 1992 Polar Star cruise to the Northwind Ridge region, Canada Basin. Surface sample ostracode assemblages from the 1993 Polarstern cruise to the Barents and Laptev Seas (Fütterer, 1994) are given in Cronin (in press; special volume on Arctic Ocean surface sediments, Stein et al., eds.).

fossil.txt Fossil census data

fossil.tab Fossil census data

This file contains the downcore ostracode census counts from Cronin et al. (1994) for 18 GKG boxcores and 1 KAL kastenlot core from the 1991 Polarstern cruise (Fütterer, 1992). Ostracode faunal slides from these cores are housed in the U.S. Geological Survey, Reston, Virginia. Columns 2 and 3 are the top and bottom core depths for each sample. Taxon numbers 1-103 are keyed to the taxonomic name table.

multicor.txt Multicore (MUC) census data

This file contains the downcore ostracode species census counts from Cronin et al. (1995) for eight multicores (MUC) from the Eurasian Basin of the Arctic Ocean obtained during the 1991 Polarstern cruise (Fütterer, 1992). Ostracode faunal slides from these cores are housed in the U.S. Geological Survey, Reston, Virginia. Columns 2 and 3 are the top and bottom core depths for each sample. Taxon numbers 1-103 are keyed to the taxonomic name table.

Acknowledgements

sWe are grateful to the shipboard scientists and crews of cruises who obtained Arctic cores and samples that provided the material for this database. We are also especially appreciative of the following colleagues who have freely and kindly provided material for ostracode study: Dr. J. T. Andrews, K. Foley, Prof. D. Fütterer, Dr. A. Grantz, Dr. S. Ishman, Dr. E. Reimnitz, Dr. P. Barnes, Dr. S. Lehman, Dr. A. Mackensen, Dr. D. Nurnberg, Dr. L. Polyak, Dr. R.Z. Poore, Dr. R. Spielhagen, Dr. R. Stein, Prof. J. Thiede, Dr. C. Vogt, Dr. J. Wollenburg. Much of the ostracode research was supported by the U.S. Geological Survey (USGS) Global Change and Climate History Program, in collaboration with INSTAAR (University of Colorado) and the Institute of Earth Studies, Aberystwyth, (University College, Wales), and with assistance from the Alfred Wegener Institute (Bremerhaven) and GEOMAR (Kiel). Most of the taxonomy of this database was agreed upon at a conference on deep-sea Ostracoda held in summer, 1993, at the USGS in Reston, Virginia, sponsored by the USGS Global Change and Climate History Program.

References

Contacts

Thomas M. Cronin
  Mail Stop 955
  U.S. Geological Survey
  Reston, Virginia 22092

  Tel: (703) 648-6363
  FAX: (703) 648-6688
  email: tcronin@geochange.er.usgs.gov

Thomas R. Holtz, Jr.
  Department of Geology
  University of Maryland
  College Park, MD 20742

  Tel: (301) 405-4084
  FAX: (301) 314-9661
  email: Thomas_R_Holtz@umail.umd.edu

Elisabeth M. Brouwers
  Mail Stop 919
  U.S. Geological Survey
  Box 25046, Denver Federal Center
  Denver, CO 80225-0046

  Tel: (303) 236-5667
  FAX:
  email: brouwers@usgs.gov

William M. Briggs, Jr.
  Institute for Arctic and Alpine Research
  Campus Box 450
  University of Colorado
  Boulder, CO 80309

  Tel: (303) 492-8971
  FAX:
  email: briggs@spot.colorado.edu

Robin C. Whatley
  Institute for Earth Studies
  University of Wales
  Dyfed, Aberystwyth SY23 3DB
  Wales, UK

  Tel: 044-970-62-3111
  FAX:
  email: riw@aberystwyth.ac.uk

Adrian Wood
  School of Natural and Environmental Sciences
  Division of Geography
  Coventry University
  Priory Street,
  Coventry CV1 5FB, UK

  Tel: 1203 83 87 57
  FAX: 1203 83 87 53
  email apx071@coventry.ac.uk
This page is <URL:http://geochange.er.usgs.gov/pub/data/PRISM/ostracodes/arctic/Core/meta/report.html>
Maintained by Peter Schweitzer
Last updated 25-Jan-1995