Aragonite distribution and preservation of sediment cores from the Brazilian Continental Slope, 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

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, aragoni...

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Bibliographic Details
Main Authors: Gerhardt, Sabine, Groth, H, Rühlemann, Carsten, Henrich, Rüdiger
Format: Article in Journal/Newspaper
Language:English
Published: PANGAEA - Data Publisher for Earth & Environmental Science 2000
Subjects:
Online Access:https://dx.doi.org/10.1594/pangaea.712059
https://doi.pangaea.de/10.1594/PANGAEA.712059
Description
Summary: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.