Silt grain-size analysis of ODP holes from the western equatorial Atlantic ...

• Main Authors: Gröger, Matthias, Henrich, Rüdiger, Bickert, Torsten
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 2003
• Subjects: Drilling/drill rig; Leg154; Joides Resolution; Geosciences, University of Bremen GeoB; Ocean Drilling Program ODP; North Atlantic Deep Water; North Atlantic
• Online Access: https://dx.doi.org/10.1594/pangaea.736009; https://doi.pangaea.de/10.1594/PANGAEA.736009

Grain-size records of the terrigenous and calcareous silt fraction, preservation of planktic foraminifera, and benthic foraminiferal stable-isotope data (delta13C, delta18O values of C. wuellerstorfi) at ODP Site 927 on the Ceará Rise (5°27.7'N, 44°28.8'W), are used to reconstruct variations in the history of bottom current strength, ventilation, and carbonate corrosiveness of deep waters during the time interval from 0.8 to 0.3 Ma. Glacial periods are characterized by generally smaller mean sizes of the terrigenous sortable silt fraction (mean(SS)), lower delta13C values, and poorer preservation of planktic foraminifera compared to interglacials. This indicates lower bottom current speeds, larger nutrient contents and more corrosive deep water. By contrast, larger mean(SS) sizes, higher delta13C values, and well preserved planktic foraminifera indicate strong circulation and a well ventilated deep-water mass during interglacials. The observed changes are most likely related to the weakening and ... : Supplement to: Gröger, Matthias; Henrich, Rüdiger; Bickert, Torsten (2003): Glacial-interglacial variability in lower North Atlantic deep water: inference from silt grain-size analysis and carbonate preservation in the western equatorial Atlantic. Marine Geology, 201(4), 321-332 ...