Publication Date:
2024-06-25
Description:
We explored the potential to use the stable isotopic compositions of planktonic foraminifera as a proxy for the position of the Brazil-Malvinas Confluence (BMC) in the Argentine Basin. For this purpose, we measured the oxygen and carbon isotopic compositions of Globigerinoides ruber (pink and white varieties measured separately), Globigerinoides trilobus, Globigerina bulloides, Globorotalia inflata and Globorotalia truncatulinoides (left- and right-coiling forms measured separately) from a latitudinal transect of 56 surface sediment samples from the continental slope off Brazil, Uruguay and Argentina between 20 and 48°S. Lowest oxygen isotopes values were found in G. ruber (pink), followed by G. ruber (white) and G. trilobus reflecting the highly stratified near surface water conditions north of the BMC. Globigerina bulloides was present mainly south of the BMC and records subsurface conditions supporting earlier plankton tow studies. Globorotalia inflata and G. truncatulinoides (left and right) were both available over the whole transect and calcify in the depth level with the steepest temperature change across the BMC. Accordingly, the delta18O of these species depict a sharp gradient of 2‰ at the confluence with remarkably stable values north and south of the BMC. Our data show that the oxygen isotopic composition of G. inflata and G. truncatulinoides (left and right) are the most reliable indicators for the present position of the BMC and can therefore be used to define the past migration of the front if appropriate cores are available.
Keywords:
Brazil Basin; Center for Marine Environmental Sciences; DEPTH, sediment/rock; Elevation of event; Event label; GeoB2102-1; GeoB2104-1; GeoB2105-3; GeoB2106-1; GeoB2107-5; GeoB2109-3; GeoB2119-2; GeoB2124-1; GeoB2126-1; GeoB2130-1; GeoB2707-4; GeoB2712-1; GeoB2714-5; GeoB2715-1; GeoB2718-1; GeoB2719-2; GeoB2722-2; GeoB2723-2; GeoB2726-3; GeoB2727-1; GeoB2802-2; GeoB2803-1; GeoB2804-2; GeoB2805-1; GeoB3205-2; GeoB3207-2; GeoB6202-5; GeoB6203-1; GeoB6204-2; GeoB6205-1; GeoB6208-1; GeoB6209-2; GeoB6210-1; GeoB6214-5; GeoB6216-1; GeoB6217-2; GeoB6218-1; GeoB6220-1; GeoB6222-2; GeoB6231-1; GeoB6232-1; GeoB6233-1; GeoB6234-1; GeoB6309-2; GeoB6310-1; GeoB6311-2; GeoB6312-1; GeoB6313-2; GeoB6314-2; GeoB6317-2; GeoB6330-1; GeoB6334-2; GeoB6336-2; GeoB6908-1; GeoB6909-2; GeoB6911-2; Giant box corer; GKG; Globigerina bulloides, δ13C; Globigerina bulloides, δ18O; Globigerinoides ruber pink, δ13C; Globigerinoides ruber pink, δ18O; Globigerinoides ruber white, δ13C; Globigerinoides ruber white, δ18O; Globigerinoides trilobus, δ13C; Globigerinoides trilobus, δ18O; Globorotalia inflata, δ13C; Globorotalia inflata, δ18O; Globorotalia truncatulinoides dextral, δ13C; Globorotalia truncatulinoides dextral, δ18O; Globorotalia truncatulinoides sinistral, δ13C; Globorotalia truncatulinoides sinistral, δ18O; Gravity corer (Kiel type); JOPSII-8; Latitude of event; Longitude of event; M23/2; M29/1; M29/2; M46/2; M46/3; M49/3; MARUM; Mass spectrometer Finnigan MAT 252; Meteor (1986); MUC; MultiCorer; off Macaé; SL; Slope off Argentina; Stratigraphy; Uruguay continental margin; Victor Hensen; western South Atlantic
Type:
Dataset
Format:
text/tab-separated-values, 556 data points
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