Here we present new results on the sedimentation rates and vertical mixing in the deep-water region (966–3741 m) of the southern Gulf of Mexico, from a collection of 42 cores retrieved from the continental slopes and the abyssal plain. These cores were dated with the aid of accelerator mass spectrometry (AMS) ¹⁴C determinations on planktic foraminifera. We applied the Modified Mixing Box Model (MMBM) to evaluate the mean sedimentation rates (S_m), to estimate the age of surface sediments (T₀) that result from mixing processes. S_m range between 5 and 9 cm kyr⁻¹ in cores from the abyssal plain and the continental slopes, highest rates are consistently observed in specific locations on the slopes (17–24 cm kyr⁻¹). T₀ values range between 1000 and 2000 years, in cores from the abyssal plain and the continental slope sites, most probably as a result from the relatively low sedimentation rates and consequent mixing of older sediments. However, some cores from the continental slopes show consistently higher sedimentation rates, and T₀ values that are close to zero age. Here we further show ²¹⁰Pb profiles from 15 cores to evaluate the non-homogeneous mixing processes in surface sediments (0–10 cm). Biodiffusion coefficients (D_b) derived from the solution of advection-diffusion model range between 14 and 51 cm² kyr⁻¹ on the abyssal plain and between 42 and 158 cm² kyr⁻¹ on the continental slopes.

Fluxes of ²¹⁰Pb_ex range between 60 and 111 Bq m⁻² yr⁻¹ on the abyssal plain, and higher values are consistently found on the continental slopes (158–247 Bq m⁻² yr⁻¹). We find the age of surface sediments (T₀; derived from the MMBM of ¹⁴C) are linked with the transit time in the mixed layer through biodiffusion processes, derived from ²¹⁰Pb profiles. One of the implications of these results is the relative low importance of benthic macrofauna in respect to the meio- and microfauna bioturbation processes to explain sediment mixing patterns in the deep-sea sediments of the Gulf of Mexico, most probably reflecting a low export of organic carbon to the sediments controlled by the oligotrophic conditions of its surface waters.

在这里，我们从墨西哥湾南部和深海平原取回的42个岩心中，得出了墨西哥湾南部深水区（966–3741 m）的沉积速率和垂直混合的新结果。这些核是通过对板状有孔虫的加速器质谱（AMS）¹⁴ C测定确定日期的。我们应用了改进的混合箱模型（MMBM）来评估平均沉降速率（S _m），以估计混合过程产生的表面沉积物的年龄（T ₀）。S _m范围介于5到9 cm kyr ^-1之间在深海平原和大陆斜坡的岩心中，在斜坡的特定位置（17–24 cm kyr ^-1）始终观察到最高比率。T ₀值的范围在1000年到2000年之间，位于深海平原和大陆斜坡部位的核心地带，最可能的原因是相对较低的沉积速率和随后的较旧沉积物的混合。但是，大陆斜坡的一些岩心始终显示出较高的沉积速率，T ₀值接近于零年龄。在这里，我们进一步显示了来自15个岩心的²¹⁰ Pb剖面，以评估表层沉积物（0-10 cm）中的非均匀混合过程。生物扩散系数（D _b）源自对流扩散模型的解，在深海平原上介于14和51 cm ² kyr ^-1之间，在大陆斜坡上介于42和158 cm ² kyr ^-1之间。

²¹⁰ Pb _ex的通量在深海平原上介于60和111 Bq m ^-2  yr ^-1之间，并且在陆坡（158-247 Bq m ^-2  yr ^-1）上始终发现较高的值。我们发现表面沉积物的年龄（T ₀；源自¹⁴ C的MMBM ）与通过生物扩散过程（从²¹⁰得出）在混合层中的传播时间有关。铅剖面。这些结果的含义之一是，底栖大型动物相对于中，微型动物生物扰动过程的重要性相对较低，以解释墨西哥湾深海沉积物中的沉积物混合模式，这很可能反映了有机物的低排放。碳到受其表层水的贫营养条件控制的沉积物中。