Fig. 3
From: Transient hydrodynamic effects influence organic carbon signatures in marine sediments
Deglacial trends in down-core records at SHAK06-5K and vicinal Iberian Margin ocean cores. Comparison of down-core sedimentary proxies at Iberian margin sites during glacial termination and Holocene. a Radiocarbon age offset between grain-size sediment fractions (clay [C], fine silt [FS], coarse silt [CS], foraminifera [F]; Rx–y = Rx – Ry, where x and y represent discrete sediment fractions [c.f., eq. 1]) isolated from the same sediment core intervals of SHAK06-5K. Also shown are propagated 1σ (s.d.) uncertainties of differences in radiocarbon age among grain-size sediment fractions (c.f., Supplementary Data 1). b Average sedimentation rates of the sediments at SHAK06-5K (black line [c.f., Supplementary Data 1]), together with bulk percent total organic carbon (TOC%) for respective sediments (N.B., the axis reversal for improved down-core comparisons). c Relative sea-level (RSL) fluctuations of the southeast Portuguese margin27,28 (blue solid line) beside corresponding global RSL data with depth uncertainties85. The rate of sea-level change is also shown, as modeled in Monte Carlo experiments with 6 m coral depth uncertainty86. d Zirconium-to-Aluminum (Zr/Al) ratios of bulk sediments at SHAK06-5K (green solid line). Raw values are natural-log transformed to improve data normality. Also shown are relative abundance (percentage) of reworked nannofossils in down-core sediments at SHAK06-5K (c.f., Supplementary Data 4). e Manganese-to Aluminum (Mn/Al) ratios of bulk sediments at SHAK06-5K, which serve as a relative indicator of benthic redox conditions22. f Difference between normalized Zr/Al ratios at U1386 and U1389 (ref. 40) that theoretically presents a surrogate measure of MOW flow depth43. g Radiocarbon age offset between co-occurring grain-size classes as compared to clays at SHAK06-5K. Again, corresponding propagated 1σ uncertainties of differences in radiocarbon age among grain-size sediment fractions are also shown (c.f., Supplementary Data 1). g Alkenone concentrations (C37:2 + C37:3 [light blue solid line]) for at MD95-2042 (ref. 14); higher values indicate increasing primary production or increases in organic matter preservation55. Also shown is excess 231Pa-to-230Th ratio at SU18-81 (green solid line), demonstrative of bottom-water circulation strength2. h Parallel down-core reconstructions of sea-surface temperature at MD95-2042 derived from coincident foraminifera assemblages67 (purple solid line), alkenones (light blue67 and dark blue14 solid lines, respectively) and tetraethers14 (green solid line). Also shown is calculated orbital precession (dashed black line), which equals the product of calculated eccentricity (e) and the sine function of longitude of the perihelion (ω). Dashed lines connecting points represent intervals of low data resolution and high meltwater release, which could drive anomalous radiocarbon values1,83. BA Bølling/Allerød, HE1 Heinrich Event 1, LGM Last Glacial Maximum, YD Younger Dryas
