Calcium Carbonate Database: README NGDC Data Set # 0998 (LDEO data) NGDC Data Set # 1021 (Brown Univ. data) obtained from: U.S. Department of Commerce National Environmental Satellite, Data, and Information Service National Oceanic and Atmospheric Administration U.S. National Geophysical Data Center (NGDC) (http://www.ngdc.noaa.gov/mgg/mggd.html) & collocated World Data Center for Marine Geology & Geophysics This data set also available from WDC Paleoclimatology _______________________________________________________________________ NOTE: PLEASE CITE ORIGINAL REFERENCE WHEN USING THESE DATA _______________________________________________________________________ CONTRIBUTORS: William Ruddiman, Lamont-Doherty Earth Observatory John Farrell, Brown University NAME OF DATA SET: Calcium Carbonate Database LAST UPDATE: 1/92 (Addition of Farrell sites) GEOGRAPHIC REGION: Global PERIOD OF RECORD: 0 - 3,000,000 YBP DATA VOLUME: approxmately 2.3 mbytes MGG IDENTIFIER : MGG01995005 (LDEO carbonate) MGG44995002 (Brown University carbonate) LIST OF FILES *.tot (313 files, CaCO3 %, total sediment), *.fin (53 files, CaCO3 %, fine sediment fraction), table* (7 files, Farrell age models), README (this file) Additional files available from WDC-Paleoclimatology = 6 program files. SUMMARY This data set contains calcium carbonate percentage data from marine sediment cores, plus C14 dates or age models as available. Display software is available from the WDC Paleoclimatology via anonymous ftp, as are the data files. Analyses were done for the CLIMAP project, and for numerous regional studies. On average, the cores span 100,000 to 200,000 years, sampled at intervals averaging 3,000 to 10,000 years. Numerous cores span only the last deglaciation, while a few cover intervals up to 3,000,000 years. Samples analyzed consisted of either bulk sediment, or fine-fraction sediment passed through either a 63 or 74 micron sieve. There is no significant difference in analyses based on these two fine fractions, and the sieve size is not recorded in the files. There is also little difference between fine and total fraction analyses, but the two types are distinguished by file extension. C14 ages for the LDEO data are in the LDEO C14 data set. Age models for the Farrell data are found in Tables 1-3, and in the respective data files. AVAILABILITY Data are available at no charge from NGDC's Web server. Files are also available on other media through NGDC's Marine Geology & Geophysics Division (WDC for Marine Geology and Geophysics): WDC Paleoclimatology Technical Contact: Dr. David Anderson NOAA/NGDC E/GC 325 Broadway Boulder, CO 80305 USA phone: 303-497-6237 fax: 303-497-6513 DATA FILE COMMENTS Core k708-6 carb ff: turbidite between, approximately, 910-960 cm. Core k708-1 carb: turbidite between, approximately, 750-758 cm. References: (Analysis Techniques) Mercury Rig, Hulsemann, Journal of Sedimentary Petrology, 1966 Vacuum Precision, Jones and Kaiteris, Journal of Sedimentary Petrology, 1983 LDEO DATA SUMMARY LDEO Carbonate data were compiled under the direction of A. Esmay and W.F. Ruddiman at the Lamont-Doherty Earth Observatory of Columbia University. Data include CaCO3 percentages by interval down core for 328 sediments cores, principally from the Atlantic ocean. Data are derived primarily from two sources. First, cores analyzed during the CLIMAP project to generate stratigraphic control on cores from key deep-sea regions. Second, cores analyzed using almost entirely National Science Foundation funds, but through smaller grants to individuals and institutions. On average, cores span intervals of time of 100,000 to 200,000 years and have been analyzed at time steps of a few thousand years. Several cores span only the last deglaciation; a few cores cover much longer intervals, up to 3 million years. Samples are annotated as either bulk sediment, or fine-fraction (<63 or 74 micron) subsets. Station information is included. BROWN DATA SUMMARY Weight percentages of calcium carbonate in the Brown file were compiled by J. Farrell and W. L. Prell of Brown University for 17 equatorial Pacific Ocean sediment cores. Cores are identified by cruise and core id. Depth-in-core information and estimates of sediment age, by depth, in millions of years (Ma) are included. Carbonate percentages are weight percent of bulk samples, rounded to the nearest integer. Models used to generate (by linear interpolation) ages also included in table form. Ages are based primarily on paleomagnetic stratigraphy, refined by oxygen isotope stratigraphy, and correlation of CaCO3 events among cores, and range from 0 to 4 million years. Comments on biostratigraphy, delta oxygen 18, calcium carbonate events, and core quality are also included on age model tables. LDEO DOCUMENTATION RECEIVED WITH DATA LDGO Carbonate Files - 1990: explanation by Dr. William Ruddiman, LDGO The 1990 entry in the LDGO carbonate files consists of CaCO3 analyses from several hundred cores from the world ocean, mainly in the Atlantic but also in the other oceans. These analyses derive mainly from two sources. First, numerous cores were analysed for the CLIMAP project in the 1970's and early 1980's. These analyses were run to generate initial stratigraphic control on deep-sea cores from key deep-sea regions. Prior to the wide use of oxygen-isotopic signals, CaCO3 curves provided a means of correlating locally among cores with various degrees of chronologic control. All analyses were made under NSF funding. The second group of cores represents analyses carried out under funding of smaller grants to individuals or groups, also run almost entirely on NSF funding. These projects involved regional paleoceano- graphic studies in regions of strong frontal contrasts and marked glacial-interglacial variability. On average, the cores span intervals of time of about 100,000-200,000 years and have been analysed at time steps averaging a few thousand years (~3,000-10,000). Numerous cores span only the last deglaciation; a small number of records cover much longer intervals (up to ~3 million years). Almost all cores were analysed by one of two techniques: Equipment Publication Reproducibility "Mercury rig" Hulsemann (1966) 3-4% (J. Sed. Pet.) Vacuum precision Jones & Kaiteris (1983) 1% (J. Sed. Pet.) A few records were analysed by the "Karbonate Bomb" method (Muller and Gastner, 1971, N. Jahrb. Mineral. Monatsh). The samples analysed consisted either of bulk sediment, or of fine- fraction sediment that passed through a 63 or 74 micron seive. There is no significant difference between analyses based on these fine fractions, and so that size distinction is not made in these listings. For most cores, there is also little difference between fine-fraction and whole-sediment analyses, but these two types are distinguished here. There will be some additional entries made in the next year, mainly of data from sources outside Lamont and CLIMAP; however, there are no long- term plans to archive future CaCO3 data except that generated under normal funding. rec'd June 1, 1990 by NGDC/WDC for MGG.