Bromine counts from XRF scanning as an estimate of the marine organic carbon content of sediment cores

• Published in: Geochemistry, geophysics, geosystems : G3 Vol. 9; no. 5; pp. Q05009 - n/a
• Main Authors: Ziegler, Martin, Jilbert, Tom, de Lange, Gert J., Lourens, Lucas J., Reichart, Gert-Jan
• Format: Journal Article
• Language: English
• Published: American Geophysical Union 01.05.2008; Blackwell Publishing Ltd
• Subjects: bromine; Geochemistry; Instruments and techniques; Marine Geology and Geophysics; Ocean drilling; sediment chemistry; Sedimentary geochemistry; sedimentary organic carbon; X-ray fluorescence; XRF core scanner; ISW, Arabian Sea; MED; bromine; X-ray fluorescence; sediment chemistry; XRF core scanner; sedimentary organic carbon
• ISSN: 1525-2027; 1525-2027
• DOI: 10.1029/2007GC001932

XRF sediment core scanning technology is increasingly used to quantify sediment composition. The overall good correlation between biophilic halogen bromine (Br) and sedimentary total organic carbon (TOC) potentially allows the fast estimation of down core TOC profiles by XRF scanning. In order to test this approach we present data from the Arabian Sea and a Mediterranean brine basin, comparing XRF core scanning Br data with discrete sample TOC analyses. Overall, Br counts and TOC show a clear correlation, except when stable carbon isotope and C/N data indicate intervals characterized by enhanced input of terrestrial organic matter. Hence, solid phase Br is exclusively associated with marine organic matter (MOC) and can be used as a direct estimate of this parameter after a calibration is established. High pore water Br in the brine core steepens the Br/TOC correlation but after salt correction shows a nearly identical gradient to that of the Arabian Sea core.