Sediment accumulation rates and vertical mixing of deep-sea sediments derived from14C and 210Pb in the southern Gulf of Mexico

• DOI: 10.1016/j.margeo.2020.106288
• Publication Date: 2020-08-01T17:14:53Z
• Authors: Misael Díaz-Asencio; Juan Carlos Herguera; Patrick T. Schwing; Rebekka A. Larson; Gregg R. Brooks; John Southon; Patrick Rafter
• Keywords: Abyssal plain; Abyssal zone; Sedimentation

Here we present new results on the sedimentation rates and vertical mixing in deep-water region (966–3741 m) of southern Gulf Mexico, from a collection 42 cores retrieved continental slopes abyssal plain. These were dated with aid accelerator mass spectrometry (AMS) 14C determinations planktic foraminifera. We applied Modified Mixing Box Model (MMBM) to evaluate mean (Sm), estimate age surface sediments (T0) that result processes. Sm range between 5 9 cm kyr−1 plain slopes, highest are consistently observed specific locations (17–24 kyr−1). T0 values 1000 2000 years, slope sites, most probably as relatively low consequent older sediments. However, some show higher rates, close zero age. further 210Pb profiles 15 non-homogeneous processes (0–10 cm). Biodiffusion coefficients (Db) derived solution advection-diffusion model 14 51 cm2 158 slopes. Fluxes 210Pbex 60 111 Bq m−2 yr−1 plain, found (158–247 yr−1). find (T0; MMBM 14C) linked transit time mixed layer through biodiffusion processes, profiles. One implications these is relative importance benthic macrofauna respect meio- microfauna bioturbation explain sediment patterns deep-sea reflecting export organic carbon controlled by oligotrophic conditions its waters.