Aragonite distribution and preservation of sediment cores from the Brazilian Continental Slope
Cobertura |
MEDIAN LATITUDE: -8.601190 * MEDIAN LONGITUDE: -34.146905 * SOUTH-BOUND LATITUDE: -8.735000 * WEST-BOUND LONGITUDE: -34.345000 * NORTH-BOUND LATITUDE: -8.528333 * EAST-BOUND LONGITUDE: -34.021667 * DATE/TIME START: 1993-03-22T00:00:00 * DATE/TIME END: 1993-03-23T00:00:00 |
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Data(s) |
29/01/2000
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Resumo |
We present late Quaternary records of aragonite preservation determined for sediment cores recovered on the Brazilian Continental Slope (1790-2585 m water depth) where North Atlantic Deep Water (NADW) dominates at present. We have used various indirect dissolution proxies (carbonate content, aragonite/calcite contents, and sand percentages) as well as gastropodal abundances and fragmentation of Limacina inflata to determine the state of aragonite preservation. In addition, microscopic investigations of the dissolution susceptibility of three Limacina species yielded the Limacina Dissolution Index which correlates well with most of the other proxies. Excellent preservation of aragonite was found in the Holocene section, whereas aragonite dissolution gradually increases downcore. This general pattern is attributed to an overall increase in aragonite corrosiveness of pore waters. Overprinted on this early diagenetic trend are high-frequency fluctuations of aragonite preservation, which may be related to climatically induced variations of intermediate water masses. |
Formato |
application/zip, 7 datasets |
Identificador |
https://doi.pangaea.de/10.1594/PANGAEA.712059 doi:10.1594/PANGAEA.712059 |
Idioma(s) |
en |
Publicador |
PANGAEA |
Relação |
Gerhardt, Sabine (2001): Late Quaternary water mass variability derived from the pteropod preservation state in sediments of the western South Atlantic Ocean and the Caribbean Sea. Berichte aus dem Fachbereich Geowissenschaften der Universität Bremen, 171, 109 pp, urn:nbn:de:gbv:46-ep000102968 |
Direitos |
CC-BY: Creative Commons Attribution 3.0 Unported Access constraints: unrestricted |
Fonte |
Supplement to: Gerhardt, Sabine; Groth, H; Rühlemann, Carsten; Henrich, Rüdiger (2000): Aragonite preservation in late Quaternary sediment cores on the Brazilian Continental Slope: implications for intermediate water circulation. International Journal of Earth Sciences, 88(4), 607-618, doi:10.1007/s005310050291 |
Palavras-Chave | #% carbonate; absolute; absoulte; Aragonite; Arg; Brazil Basin; CaCO3; Calcium carbonate; Calculated; Counting; Depth; DEPTH, sediment/rock; Element analyser CHN; Foraminifera, planktic; Foram plankt; fragments; Gastropoda; GeoB2204-1; GeoB2204-2; GeoB2205-4; GeoB2207-2; Grain size, sieving/settling tube; Gravity corer (Kiel type); L. bulimoides; L. inflata; L. inflata; (g+b)/(g+b+f); L. lesueuri; LDX; LFX; Limacina dissolution index; Limacina fragmentation index; Limacinidae; M23/3; Meteor (1986); MUC; MultiCorer; Sand; SFB261; SL; South Atlantic in Late Quaternary: Reconstruction of Budget and Currents; whole tests + damaged tests; X-ray diffraction (XRD) |
Tipo |
Dataset |