Modern major element concentrations and ratios measured in Atlantic surface sediments (36°N-49°S)


Numerous studies use major element concentrations measured on continental margin sediments to reconstruct terrestrial climate variations. The choice and interpretation of climate proxies however differ from site to site. Here we map the concentrations of major elements (Ca, Fe, Al, Si, Ti, K) in Atlantic surface sediments (36°N-49°S) to assess the factors influencing the geochemistry of Atlantic hemipelagic sediments and the potential of elemental ratios to reconstruct different terrestrial climate regimes. High concentrations of terrigenous elements and low Ca concentrations along the African and South American margins reflect the dominance of terrigenous input in these regions. Single element concentrations and elemental ratios including Ca (e.g., Fe/Ca) are too sensitive to dilution effects (enhanced biological productivity, carbonate dissolution) to allow reliable reconstructions of terrestrial climate. Other elemental ratios reflect the composition of terrigenous material and mirror the climatic conditions within the continental catchment areas. The Atlantic distribution of Ti/Al supports its use as a proxy for eolian versus fluvial input in regions of dust deposition that are not affected by the input of mafic rock material. The spatial distributions of Al/Si and Fe/K reflect the relative input of intensively weathered material from humid regions versus slightly weathered particles from drier areas. High biogenic opal input however influences the Al/Si ratio. Fe/K is sensitive to the input of mafic material and the topography of Andean river drainage basins. Both ratios are suitable to reconstruct African and South American climatic zones characterized by different intensities of chemical weathering in well-understood environmental settings.

Supplement to: Govin, Aline; Holzwarth, Ulrike; Heslop, David; Ford Keeling, Lara; Zabel, Matthias; Mulitza, Stefan; Collins, James A; Chiessi, Cristiano Mazur (2012): Distribution of major elements in Atlantic surface sediments (36°N–49°S): Imprint of terrigenous input and continental weathering. Geochemistry, Geophysics, Geosystems, 13(1), Q01013

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Creator Govin, Aline ORCID logo; Holzwarth, Ulrike; Heslop, David ORCID logo; Ford Keeling, Lara; Zabel, Matthias ORCID logo; Mulitza, Stefan ORCID logo; Collins, James A; Chiessi, Cristiano Mazur ORCID logo
Publisher PANGAEA
Publication Year 2012
Rights Creative Commons Attribution 3.0 Unported;
OpenAccess true
Resource Type Supplementary Dataset; Dataset
Format text/tab-separated-values
Size 1687 data points
Discipline Earth System Research
Spatial Coverage (-60.092W, -48.912S, 18.091E, 36.023N); West Angola Basin; Brazil Basin; Amazon Fan; Guinea Basin; off Kunene; Namibia continental slope; Angola Diapir Field; Angola Benguela Front; Slope off Argentina; Uruguay continental margin; Santos Plateau; Western Equatorial Atlantic; Sierra Leone Rise; Southern Cape Basin; Northern Cape Basin; Mid Atlantic Ridge; Northeast Brasilian Margin; Atlantic Caribbean Margin; Agadir Canyon; Midatlantic Ridge; Northern Brasil Basin; Ceara Rise; Guayana continental slope; Eastern Niger fan; NE off San Thome; off northern Gabun; off Cameroon; off Gabun; off Angola; Angola Basin; Central Brazil Basin; Central South Atlantic; Congo Fan; Walvis Bay/Namibia; off Northwest Africa; Mauritania Canyon; off NW Africa
Temporal Coverage Begin 1991-04-16T00:00:00Z
Temporal Coverage End 2005-07-20T13:59:00Z