Abstract
Quantitative knowledge about the burial of sedimentary components at the
seafloor has wide-ranging implications in ocean science, from global
climate to continental weathering. The use of 230 Th-normalized fluxes
reduces uncertainties that many prior studies faced by accounting for
the effects of sediment redistribution by bottom currents and minimizing
the impact of age model uncertainty. Here we employ a recently compiled
global dataset of 230 Th-normalized fluxes with an updated database of
seafloor surface sediment composition to derive global maps of the
burial flux of calcium carbonate, biogenic opal, total organic carbon
(TOC), non-biogenic material, iron, mercury, and excess barium (Baxs).
The spatial patterns of burial of the major components are mainly
consistent with prior work, but the new quantitative estimates allow
evaluations of global deep-sea burial. Our integrated deep-sea burial
fluxes are 136 Tg C/yr CaCO3, 153 Tg Si/yr opal, 20Tg C/yr TOC, 220 Mg
Hg/yr, and 2.6 Tg Baxs/yr. Sedimentary Fe fluxes reflect a mixture of
sources including lithogenic material, hydrothermal inputs and
authigenic phases. The fluxes of some commonly used paleo-productivity
proxies (TOC, biogenic opal, and Baxs) are not well-correlated
geographically with satellite-based productivity estimates. Our new
compilation of sedimentary fluxes provides more detailed information on
burial fluxes, which should lead to improvements in the understanding of
how preservation affects these paleoproxies.