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

• 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: MultiCorer; Gravity corer Kiel type; M23/3; Meteor 1986; South Atlantic in Late Quaternary Reconstruction of Budget and Currents SFB261; NADW; North Atlantic Deep Water; North Atlantic
• Online Access: https://dx.doi.org/10.1594/pangaea.712059; https://doi.pangaea.de/10.1594/PANGAEA.712059

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.