1 research outputs found
South American Hydrological Balance and Paleoceanography during the Late Pleistocene and Holocene (SAMBA) – Cruise No. M125, March 21 – April 15, 2016 - Rio de Janeiro (Brazil) – Fortaleza (Brazil)
R/V METEOR expedition M125 (“SAMBA”) focused on the influence of paleoceanographic
changes off NE Brazil on the continental hydrological cycle. For this purpose, we obtained 202 m
of gravity (24 stations) and piston cores (9) at seven sections on the shelf and continental slope
close to river mouths from Cabo Frio in the south to the Rio Sao Francisco in the north. Coring
stations were determined after intensive echosounder surveys (total: 1221 NM). On-board
foraminiferal biostratigraphy, as well as color and XRF-scanning already provided first
stratigraphic constraints, indicating the preservation of different regional paleoclimatic signals at
the respective sections. Based on the preliminary stratigraphy, we retrieved high-resolution
archives, covering Holocene sediments on the shelf and late Pleistocene sediments on the slope.
These high-resolution archives are complemented by long-term records covering up to 900 ka of
continuous sedimentation at deeper sites at smaller rivers. For proxy-calibration and the study of
present-day sedimentation dynamics and biogeochemical processes, surface sediments were
sampled via multicorer (47), Van Veen Grab (6) and box corer (3). Water samples for
determination of the water chemistry (trace elements, stable and radiogenic isotopes) and nutrient
composition were retrieved by 55 CTD/Rosette casts. In addition, we run multinet-hauls at seven
stations to investigate the planktonic foraminiferal communities in the water column down to 700
m water depth, complemented by filtering water from the ship’s pump twice a day