Sedimentology and planktonic foraminiferal dissolution during the latest Cretaceous in the South Atlantic ...

• Main Authors: Kucera, Michal, Malmgren, Bjorn, Sturesson, U
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 1997
• Subjects: Drilling/drill rig; Leg72; Leg74; Glomar Challenger; Deep Sea Drilling Project DSDP; Malmgren; Planktonic foraminifera; South Atlantic Ocean
• Online Access: https://dx.doi.org/10.1594/pangaea.703254; https://doi.pangaea.de/10.1594/PANGAEA.703254

A high-resolution (10-20 kyr) record of variations in CaCO3 content and dissolution was established for latest Cretaceous (last 0.7 Myr) deep-sea sediments from the South Atlantic Ocean (DSDP Site 516 from the Rio Grande Rise, and sites 525 and 527 from the Walvis Ridge). The degree of fragmentation of planktonic foraminifera (DFP) was used as a measure of calcite dissolution. High negative correlations between DFP and other independent measures of carbonate dissolution (percentage of sand fraction, absolute abundance of planktonic foraminifera, and planktonic/benthic foraminiferal ratio) validate its use as a sensitive index of calcite dissolution in upper Maastrichtian deep-sea sediments.Very high DFP and a significant negative correlation between DFP and CaCO 3 content suggest that Site 516 was located below the foraminiferal lysocline during the entire interval studied. Such a shallow position of the lysocline (paleodepth of Site 516 was 1.2 km) may be explained by "upwelling" of corrosive deep waters ... : Supplement to: Kucera, Michal; Malmgren, Bjorn; Sturesson, U (1997): Foraminiferal dissolution at shallow depths of the Walvis Ridge and Rio Grande Rise during the latest Cretaceous: Inferences for deep-water circulation in the South Atlantic. Palaeogeography, Palaeoclimatology, Palaeoecology, 129(3-4), 195-212 ...